From 4edc6bf3eed92fc5a5547406dec6760c9b062fcf Mon Sep 17 00:00:00 2001
From: dan <dan@noemail.net>
Date: Tue, 10 May 2011 17:31:29 +0000
Subject: [PATCH 01/30] Add experimental support for read-only connections to
 WAL databases.

FossilOrigin-Name: bb59f9862da45d25fb51d7821130854828c91c98
---
 manifest             |  26 ++++++----
 manifest.uuid        |   2 +-
 src/os_unix.c        |  51 +++++++++++++-----
 src/sqlite.h.in      |   4 ++
 src/test1.c          |   3 ++
 src/wal.c            |  59 +++++++++++++++------
 test/lock_common.tcl |   4 +-
 test/walro.test      | 121 +++++++++++++++++++++++++++++++++++++++++++
 8 files changed, 227 insertions(+), 43 deletions(-)
 create mode 100644 test/walro.test

diff --git a/manifest b/manifest
index daee9754e7..50889411e1 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Return\sa\ssuitable\serror\smessage\sif\sthe\smode=\sargument\sto\sa\sURI\sspecifies\na\shigher\smode\sthan\swhat\sis\sallowed\sby\scontext.\s\sOther\sminor\scleanups\sfor\nthe\sURI\sparsing\slogic.
-D 2011-05-09T19:20:17.775
+C Add\sexperimental\ssupport\sfor\sread-only\sconnections\sto\sWAL\sdatabases.
+D 2011-05-10T17:31:29.338
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 7a4d9524721d40ef9ee26f93f9bd6a51dba106f2
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -163,7 +163,7 @@ F src/os.c 22ac61d06e72a0dac900400147333b07b13d8e1d
 F src/os.h 9dbed8c2b9c1f2f2ebabc09e49829d4777c26bf9
 F src/os_common.h a8f95b81eca8a1ab8593d23e94f8a35f35d4078f
 F src/os_os2.c 4a75888ba3dfc820ad5e8177025972d74d7f2440
-F src/os_unix.c 2c67d126874b78eb427371db4793f0e8fbc7448b
+F src/os_unix.c 03630dd062c3d1fb9f25e2a227048b709c5babff
 F src/os_win.c ff0e14615a5086fa5ba6926e4ec0dc9cfb5a1a84
 F src/pager.c 24b689bc3639d534f5fb292d2c68038b1e720527
 F src/pager.h 3f8c783de1d4706b40b1ac15b64f5f896bcc78d1
@@ -179,14 +179,14 @@ F src/resolve.c 1c0f32b64f8e3f555fe1f732f9d6f501a7f05706
 F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
 F src/select.c d9d440809025a58547e39f4f268c2a296bfb56ff
 F src/shell.c 72e7e176bf46d5c6518d15ac4ad6847c4bb5df79
-F src/sqlite.h.in 41a0e4bc842917226e170273f64b95717a63270a
+F src/sqlite.h.in e7bbcb330ced6b5e25c9db8089c2c77aaefadf7d
 F src/sqlite3ext.h c90bd5507099f62043832d73f6425d8d5c5da754
 F src/sqliteInt.h b34bd64a7ade4808fcc301e0bb67ef5051ea49c6
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac64842c86cec2fc1a1d0e5c16d3beb8ad332bf
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
 F src/tclsqlite.c 501c9a200fd998a268be475be5858febc90b725b
-F src/test1.c f506164085bc4cbbb4b5c14b9c6de153f1aeafc5
+F src/test1.c 6ae026cd9d2b1b1e95a372a7460d091705db645d
 F src/test2.c 80d323d11e909cf0eb1b6fbb4ac22276483bcf31
 F src/test3.c 124ff9735fb6bb7d41de180d6bac90e7b1509432
 F src/test4.c d1e5a5e904d4b444cf572391fdcb017638e36ff7
@@ -245,7 +245,7 @@ F src/vdbeblob.c c3ccb7c8732858c680f442932e66ad06bb036562
 F src/vdbemem.c 0498796b6ffbe45e32960d6a1f5adfb6e419883b
 F src/vdbetrace.c 5d0dc3d5fd54878cc8d6d28eb41deb8d5885b114
 F src/vtab.c 48dcef8bc757c2e7b488f68b5ddebb1650da2450
-F src/wal.c 7334009b396285b658a95a3b6bc6d2b016a1f794
+F src/wal.c 2574b16ee88b1934e97f63ae38025dc48ef45327
 F src/wal.h 7a5fbb00114b7f2cd40c7e1003d4c41ce9d26840
 F src/walker.c 3112bb3afe1d85dc52317cb1d752055e9a781f8f
 F src/where.c 55403ce19c506be6a321c7f129aff693d6103db5
@@ -547,7 +547,7 @@ F test/lock4.test c82268c031d39345d05efa672f80b025481b3ae5
 F test/lock5.test b2abb5e711bc59b0eae00f6c97a36ec9f458fada
 F test/lock6.test ad5b387a3a8096afd3c68a55b9535056431b0cf5
 F test/lock7.test 64006c84c1c616657e237c7ad6532b765611cf64
-F test/lock_common.tcl d279887a0ab16cdb6d935c1203e64113c5a000e9
+F test/lock_common.tcl 0c270b121d40959fa2f3add382200c27045b3d95
 F test/lookaside.test 93f07bac140c5bb1d49f3892d2684decafdc7af2
 F test/main.test 9d7bbfcc1b52c88ba7b2ba6554068ecf9939f252
 F test/make-where7.tcl 05c16b5d4f5d6512881dfec560cb793915932ef9
@@ -883,6 +883,7 @@ F test/walfault.test 58fce626359c9376fe35101b5c0f2df8040aa839
 F test/walhook.test ed00a40ba7255da22d6b66433ab61fab16a63483
 F test/walmode.test 22ddccd073c817ac9ead62b88ac446e8dedc7d2c
 F test/walnoshm.test a074428046408f4eb5c6a00e09df8cc97ff93317
+F test/walro.test 0fb4c79a9dfa1d14f46859e469d3b4844480cd9d
 F test/walshared.test 6dda2293880c300baf5d791c307f653094585761
 F test/walslow.test d21625e2e99e11c032ce949e8a94661576548933
 F test/walthread.test a25a393c068a2b42b44333fa3fdaae9072f1617c
@@ -935,7 +936,10 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P ca3797d4967361e31a8a5ce1ce8190b095f3ed4c
-R fbfaa47316ae48b91e92f26cbe2f2742
-U drh
-Z 82e3dc394cc5052bfb9a5a6a21e4f298
+P d9bc1c7fe0ca5f6973a85827330958f4d09f8171
+R 864e9c4ee7a6cf5f8240415fb38d1af8
+T *branch * wal-readonly
+T *sym-wal-readonly *
+T -sym-trunk *
+U dan
+Z 321776a9f8d852e48652ad186c3a479b
diff --git a/manifest.uuid b/manifest.uuid
index 2b8787f1e2..e39ce5418f 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-d9bc1c7fe0ca5f6973a85827330958f4d09f8171
\ No newline at end of file
+bb59f9862da45d25fb51d7821130854828c91c98
\ No newline at end of file
diff --git a/src/os_unix.c b/src/os_unix.c
index a760e2c147..d463e5917f 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -212,6 +212,7 @@ struct unixFile {
   UnixUnusedFd *pUnused;              /* Pre-allocated UnixUnusedFd */
   const char *zPath;                  /* Name of the file */
   unixShm *pShm;                      /* Shared memory segment information */
+  int readOnlyShm;                    /* True to open shared-memory read-only */
   int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */
 #if SQLITE_ENABLE_LOCKING_STYLE
   int openFlags;                      /* The flags specified at open() */
@@ -3452,6 +3453,10 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
     case SQLITE_FCNTL_SIZE_HINT: {
       return fcntlSizeHint((unixFile *)id, *(i64 *)pArg);
     }
+    case SQLITE_FCNTL_READONLY_SHM: {
+      ((unixFile*)id)->readOnlyShm = (pArg!=0);
+      return SQLITE_OK;
+    }
 #ifndef NDEBUG
     /* The pager calls this method to signal that it has done
     ** a rollback and that the database is therefore unchanged and
@@ -3541,6 +3546,7 @@ struct unixShmNode {
   char **apRegion;           /* Array of mapped shared-memory regions */
   int nRef;                  /* Number of unixShm objects pointing to this */
   unixShm *pFirst;           /* All unixShm objects pointing to this */
+  u8 readOnly;               /* True if this is a read-only mapping */
 #ifdef SQLITE_DEBUG
   u8 exclMask;               /* Mask of exclusive locks held */
   u8 sharedMask;             /* Mask of shared locks held */
@@ -3780,29 +3786,48 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
     }
 
     if( pInode->bProcessLock==0 ){
-      pShmNode->h = robust_open(zShmFilename, O_RDWR|O_CREAT,
-                               (sStat.st_mode & 0777));
+      int flags = (pDbFd->readOnlyShm ? O_RDONLY : O_RDWR|O_CREAT);
+      pShmNode->h = robust_open(zShmFilename, flags, (sStat.st_mode & 0777));
       if( pShmNode->h<0 ){
         rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShmFilename);
         goto shm_open_err;
       }
+      pShmNode->readOnly = pDbFd->readOnlyShm;
   
       /* Check to see if another process is holding the dead-man switch.
-      ** If not, truncate the file to zero length. 
-      */
-      rc = SQLITE_OK;
-      if( unixShmSystemLock(pShmNode, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
-        if( robust_ftruncate(pShmNode->h, 0) ){
-          rc = unixLogError(SQLITE_IOERR_SHMOPEN, "ftruncate", zShmFilename);
+      ** If not, zero the first few bytes of the shared-memory file to make
+      ** sure it is not mistaken for valid by code in wal.c. Except, if this 
+      ** is a read-only connection to the shared-memory then it is not possible
+      ** to check check if another process is holding a read-lock on the DMS
+      ** byte, as we cannot attempt a write-lock via a read-only file 
+      ** descriptor. So in this case, we just assume the shared-memory 
+      ** contents are Ok and proceed.  */
+      if( pShmNode->readOnly==0 ){
+        rc = SQLITE_OK;
+        if( unixShmSystemLock(pShmNode, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
+          if( pDbFd->readOnlyShm ){
+            rc = SQLITE_IOERR_SHMOPEN;
+          }else if( 4!=osWrite(pShmNode->h, "\00\00\00\00", 4) ){
+            rc = unixLogError(SQLITE_IOERR_SHMOPEN, "ftruncate", zShmFilename);
+          }
         }
+        if( rc==SQLITE_OK ){
+          rc = unixShmSystemLock(pShmNode, F_RDLCK, UNIX_SHM_DMS, 1);
+        }
+        if( rc ) goto shm_open_err;
       }
-      if( rc==SQLITE_OK ){
-        rc = unixShmSystemLock(pShmNode, F_RDLCK, UNIX_SHM_DMS, 1);
-      }
-      if( rc ) goto shm_open_err;
     }
   }
 
+  /* If the unixShmNode is read-only, but SQLITE_FCNTL_READONLY_SHM has not
+  ** been set for file-descriptor pDbFd, return an error. The wal.c module
+  ** will then call this function again with SQLITE_FCNTL_READONLY_SHM set.
+  */
+  else if( pShmNode->readOnly && !pDbFd->readOnlyShm ){
+    rc = SQLITE_IOERR_SHMOPEN;
+    goto shm_open_err;
+  }
+
   /* Make the new connection a child of the unixShmNode */
   p->pShmNode = pShmNode;
 #ifdef SQLITE_DEBUG
@@ -3923,7 +3948,7 @@ static int unixShmMap(
     while(pShmNode->nRegion<=iRegion){
       void *pMem;
       if( pShmNode->h>=0 ){
-        pMem = mmap(0, szRegion, PROT_READ|PROT_WRITE, 
+        pMem = mmap(0, szRegion, PROT_READ|(!pShmNode->readOnly?PROT_WRITE:0), 
             MAP_SHARED, pShmNode->h, pShmNode->nRegion*szRegion
         );
         if( pMem==MAP_FAILED ){
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index d78daa7672..af88e4e726 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -454,6 +454,9 @@ int sqlite3_exec(
 #define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
 #define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
 
+#define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
+#define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
+
 /*
 ** CAPI3REF: Flags For File Open Operations
 **
@@ -742,6 +745,7 @@ struct sqlite3_io_methods {
 #define SQLITE_FCNTL_CHUNK_SIZE       6
 #define SQLITE_FCNTL_FILE_POINTER     7
 #define SQLITE_FCNTL_SYNC_OMITTED     8
+#define SQLITE_FCNTL_READONLY_SHM     9
 
 
 /*
diff --git a/src/test1.c b/src/test1.c
index 8e30123433..c25fd2289d 100644
--- a/src/test1.c
+++ b/src/test1.c
@@ -163,6 +163,9 @@ const char *sqlite3TestErrorName(int rc){
     case SQLITE_IOERR_CHECKRESERVEDLOCK:
                                zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
     case SQLITE_IOERR_LOCK:          zName = "SQLITE_IOERR_LOCK";        break;
+
+    case SQLITE_READONLY_RECOVERY:   zName = "SQLITE_READONLY_RECOVERY"; break;
+    case SQLITE_READONLY_CANTLOCK:   zName = "SQLITE_READONLY_CANTLOCK"; break;
     default:                         zName = "SQLITE_Unknown";           break;
   }
   return zName;
diff --git a/src/wal.c b/src/wal.c
index 51ea18fb21..707fe12976 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -420,6 +420,7 @@ struct Wal {
   u8 writeLock;              /* True if in a write transaction */
   u8 ckptLock;               /* True if holding a checkpoint lock */
   u8 readOnly;               /* True if the WAL file is open read-only */
+  u8 readOnlyShm;            /* True if the SHM file is open read-only */
   WalIndexHdr hdr;           /* Wal-index header for current transaction */
   const char *zWalName;      /* Name of WAL file */
   u32 nCkpt;                 /* Checkpoint sequence counter in the wal-header */
@@ -528,6 +529,16 @@ static int walIndexPage(Wal *pWal, int iPage, volatile u32 **ppPage){
       rc = sqlite3OsShmMap(pWal->pDbFd, iPage, WALINDEX_PGSZ, 
           pWal->writeLock, (void volatile **)&pWal->apWiData[iPage]
       );
+      if( rc==SQLITE_CANTOPEN && iPage==0 ){
+        sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_READONLY_SHM, (void*)1);
+        rc = sqlite3OsShmMap(pWal->pDbFd, iPage, WALINDEX_PGSZ, 
+            pWal->writeLock, (void volatile **)&pWal->apWiData[iPage]
+        );
+        if( rc==SQLITE_OK ){
+          pWal->readOnly = pWal->readOnlyShm = 1;
+        }
+        sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_READONLY_SHM, (void*)0);
+      }
     }
   }
 
@@ -772,6 +783,7 @@ static void walUnlockShared(Wal *pWal, int lockIdx){
 }
 static int walLockExclusive(Wal *pWal, int lockIdx, int n){
   int rc;
+  assert( pWal->readOnlyShm==0 );
   if( pWal->exclusiveMode ) return SQLITE_OK;
   rc = sqlite3OsShmLock(pWal->pDbFd, lockIdx, n,
                         SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE);
@@ -781,6 +793,7 @@ static int walLockExclusive(Wal *pWal, int lockIdx, int n){
   return rc;
 }
 static void walUnlockExclusive(Wal *pWal, int lockIdx, int n){
+  assert( pWal->readOnlyShm==0 );
   if( pWal->exclusiveMode ) return;
   (void)sqlite3OsShmLock(pWal->pDbFd, lockIdx, n,
                          SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE);
@@ -1056,6 +1069,7 @@ static int walIndexRecover(Wal *pWal){
   assert( WAL_ALL_BUT_WRITE==WAL_WRITE_LOCK+1 );
   assert( WAL_CKPT_LOCK==WAL_ALL_BUT_WRITE );
   assert( pWal->writeLock );
+  assert( pWal->readOnlyShm==0 );
   iLock = WAL_ALL_BUT_WRITE + pWal->ckptLock;
   nLock = SQLITE_SHM_NLOCK - iLock;
   rc = walLockExclusive(pWal, iLock, nLock);
@@ -1904,24 +1918,31 @@ static int walIndexReadHdr(Wal *pWal, int *pChanged){
   badHdr = (page0 ? walIndexTryHdr(pWal, pChanged) : 1);
 
   /* If the first attempt failed, it might have been due to a race
-  ** with a writer.  So get a WRITE lock and try again.
+  ** with a writer. So lock the WAL_WRITE_LOCK byte and try again.
   */
   assert( badHdr==0 || pWal->writeLock==0 );
-  if( badHdr && SQLITE_OK==(rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1)) ){
-    pWal->writeLock = 1;
-    if( SQLITE_OK==(rc = walIndexPage(pWal, 0, &page0)) ){
-      badHdr = walIndexTryHdr(pWal, pChanged);
-      if( badHdr ){
-        /* If the wal-index header is still malformed even while holding
-        ** a WRITE lock, it can only mean that the header is corrupted and
-        ** needs to be reconstructed.  So run recovery to do exactly that.
-        */
-        rc = walIndexRecover(pWal);
-        *pChanged = 1;
+  if( badHdr ){
+    if( pWal->readOnlyShm ){
+      if( SQLITE_OK==(rc = walLockShared(pWal, WAL_WRITE_LOCK)) ){
+        walUnlockShared(pWal, WAL_WRITE_LOCK);
+        rc = SQLITE_READONLY_RECOVERY;
       }
+    }else if( SQLITE_OK==(rc = walLockExclusive(pWal, WAL_WRITE_LOCK, 1)) ){
+      pWal->writeLock = 1;
+      if( SQLITE_OK==(rc = walIndexPage(pWal, 0, &page0)) ){
+        badHdr = walIndexTryHdr(pWal, pChanged);
+        if( badHdr ){
+          /* If the wal-index header is still malformed even while holding
+          ** a WRITE lock, it can only mean that the header is corrupted and
+          ** needs to be reconstructed.  So run recovery to do exactly that.
+          */
+          rc = walIndexRecover(pWal);
+          *pChanged = 1;
+        }
+      }
+      pWal->writeLock = 0;
+      walUnlockExclusive(pWal, WAL_WRITE_LOCK, 1);
     }
-    pWal->writeLock = 0;
-    walUnlockExclusive(pWal, WAL_WRITE_LOCK, 1);
   }
 
   /* If the header is read successfully, check the version number to make
@@ -2108,7 +2129,7 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
   }
   /* There was once an "if" here. The extra "{" is to preserve indentation. */
   {
-    if( mxReadMark < pWal->hdr.mxFrame || mxI==0 ){
+    if( pWal->readOnlyShm==0 && (mxReadMark < pWal->hdr.mxFrame || mxI==0) ){
       for(i=1; i<WAL_NREADER; i++){
         rc = walLockExclusive(pWal, WAL_READ_LOCK(i), 1);
         if( rc==SQLITE_OK ){
@@ -2123,7 +2144,8 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
     }
     if( mxI==0 ){
       assert( rc==SQLITE_BUSY );
-      return WAL_RETRY;
+      assert( rc==SQLITE_BUSY || (pWal->readOnlyShm && rc==SQLITE_OK) );
+      return rc==SQLITE_BUSY ? WAL_RETRY : SQLITE_READONLY_CANTLOCK;
     }
 
     rc = walLockShared(pWal, WAL_READ_LOCK(mxI));
@@ -2359,6 +2381,7 @@ int sqlite3WalBeginWriteTransaction(Wal *pWal){
   if( pWal->readOnly ){
     return SQLITE_READONLY;
   }
+  assert( pWal->readOnlyShm==0 );
 
   /* Only one writer allowed at a time.  Get the write lock.  Return
   ** SQLITE_BUSY if unable.
@@ -2748,6 +2771,10 @@ int sqlite3WalCheckpoint(
   assert( pWal->writeLock==0 );
 
   WALTRACE(("WAL%p: checkpoint begins\n", pWal));
+  if( pWal->readOnlyShm ){
+    return SQLITE_READONLY;
+  }
+
   rc = walLockExclusive(pWal, WAL_CKPT_LOCK, 1);
   if( rc ){
     /* Usually this is SQLITE_BUSY meaning that another thread or process
diff --git a/test/lock_common.tcl b/test/lock_common.tcl
index 21f584264a..bc1eb86bdc 100644
--- a/test/lock_common.tcl
+++ b/test/lock_common.tcl
@@ -55,8 +55,8 @@ proc do_multiclient_test {varname script} {
     uplevel set $varname $tn
     uplevel $script
 
-    code2 { db2 close }
-    code3 { db3 close }
+    catch { code2 { db2 close } }
+    catch { code3 { db3 close } }
     catch { close $::code2_chan }
     catch { close $::code3_chan }
     catch { db close }
diff --git a/test/walro.test b/test/walro.test
new file mode 100644
index 0000000000..b558622cad
--- /dev/null
+++ b/test/walro.test
@@ -0,0 +1,121 @@
+# 2011 May 09
+#
+# The author disclaims copyright to this source code.  In place of
+# a legal notice, here is a blessing:
+#
+#    May you do good and not evil.
+#    May you find forgiveness for yourself and forgive others.
+#    May you share freely, never taking more than you give.
+#
+#***********************************************************************
+#
+# This file contains tests for using WAL databases in read-only mode.
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+source $testdir/lock_common.tcl
+set ::testprefix walro
+
+
+do_multiclient_test tn {
+  # These tests are only going to work on unix.
+  #
+  if {$tcl_platform(platform) != "unix"} continue
+
+  # Do not run tests with the connections in the same process.
+  #
+  if {$tn==2} continue
+  
+  # Close all connections and delete the database.
+  #
+  code1 { db close  }
+  code2 { db2 close }
+  code3 { db3 close }
+  forcedelete test.db
+  forcedelete walro
+
+  file mkdir walro
+
+  do_test 1.1.1 {
+    code2 { sqlite3 db2 test.db }
+    sql2 { 
+      PRAGMA journal_mode = WAL;
+      CREATE TABLE t1(x, y);
+      INSERT INTO t1 VALUES('a', 'b');
+    }
+    file exists test.db-shm
+  } {1}
+
+  do_test 1.1.2 {
+    file attributes test.db-shm -permissions r--r--r--
+    code1 { sqlite3 db test.db }
+  } {}
+
+  do_test 1.1.3 { sql1 "SELECT * FROM t1" }                {a b}
+  do_test 1.1.4 { sql2 "INSERT INTO t1 VALUES('c', 'd')" } {}
+  do_test 1.1.5 { sql1 "SELECT * FROM t1" }                {a b c d}
+
+  # Check that the read-only connection cannot write or checkpoint the db.
+  #
+  do_test 1.1.6 { 
+    csql1 "INSERT INTO t1 VALUES('e', 'f')" 
+  } {1 {attempt to write a readonly database}}
+  do_test 1.1.7 { 
+    csql1 "PRAGMA wal_checkpoint"
+  } {1 {attempt to write a readonly database}}
+
+  do_test 1.1.9  { sql2 "INSERT INTO t1 VALUES('e', 'f')" } {}
+  do_test 1.1.10 { sql1 "SELECT * FROM t1" }                {a b c d e f}
+
+  do_test 1.1.11 { 
+    sql2 {
+      INSERT INTO t1 VALUES('g', 'h');
+      PRAGMA wal_checkpoint;
+    }
+    set {} {}
+  } {}
+  do_test 1.1.12 { sql1 "SELECT * FROM t1" }                {a b c d e f g h}
+  do_test 1.1.13  { sql2 "INSERT INTO t1 VALUES('i', 'j')" } {}
+
+  do_test 1.2.1 {
+    code2 { db2 close }
+    code1 { db close }
+    list [file exists test.db-wal] [file exists test.db-shm]
+  } {1 1}
+  do_test 1.2.2 {
+    code1 { sqlite3 db test.db }
+    sql1 { SELECT * FROM t1 }
+  } {a b c d e f g h i j}
+
+  do_test 1.2.3 {
+    code1 { db close }
+    file attributes test.db-shm -permissions rw-r--r--
+    hexio_write test.db-shm 0 01020304 
+    file attributes test.db-shm -permissions r--r--r--
+    code1 { sqlite3 db test.db }
+    csql1 { SELECT * FROM t1 }
+  } {1 {attempt to write a readonly database}}
+  do_test 1.2.4 {
+    code1 { sqlite3_extended_errcode db } 
+  } {SQLITE_READONLY_RECOVERY}
+
+  do_test 1.2.5 {
+    file attributes test.db-shm -permissions rw-r--r--
+    code2 { sqlite3 db2 test.db }
+    sql2 "SELECT * FROM t1" 
+  } {a b c d e f g h i j}
+  file attributes test.db-shm -permissions r--r--r--
+  do_test 1.2.6 { sql1 "SELECT * FROM t1" } {a b c d e f g h i j}
+
+  do_test 1.2.7 { 
+    sql2 {
+      PRAGMA wal_checkpoint;
+      INSERT INTO t1 VALUES('k', 'l');
+    }
+    set {} {}
+  } {}
+  do_test 1.2.8 { sql1 "SELECT * FROM t1" } {a b c d e f g h i j k l}
+}
+
+finish_test

From b6d2f9c5ef0d6fa71b744bf5ccfb8ac83b5ed060 Mon Sep 17 00:00:00 2001
From: dan <dan@noemail.net>
Date: Wed, 11 May 2011 14:57:33 +0000
Subject: [PATCH 02/30] Only open a read-only connection to shared-memory if
 the "readonly_shm=1" option is specified as part of the database file URI
 (and if a read-write connection fails).

FossilOrigin-Name: 671ba5fc59f7a958e5a4138d2425b1173a442ad7
---
 manifest        | 31 ++++++++++++++-----------------
 manifest.uuid   |  2 +-
 src/attach.c    |  6 ++++--
 src/btree.h     |  1 +
 src/main.c      | 13 +++++++++++--
 src/pager.c     |  7 +++++--
 src/pager.h     |  1 +
 src/sqliteInt.h |  2 +-
 src/wal.c       | 14 +++++++++++---
 src/wal.h       |  4 ++--
 test/walro.test | 13 ++++++++++---
 11 files changed, 61 insertions(+), 33 deletions(-)

diff --git a/manifest b/manifest
index 50889411e1..3d33b8171b 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\sexperimental\ssupport\sfor\sread-only\sconnections\sto\sWAL\sdatabases.
-D 2011-05-10T17:31:29.338
+C Only\sopen\sa\sread-only\sconnection\sto\sshared-memory\sif\sthe\s"readonly_shm=1"\soption\sis\sspecified\sas\spart\sof\sthe\sdatabase\sfile\sURI\s(and\sif\sa\sread-write\sconnection\sfails).
+D 2011-05-11T14:57:33.029
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 7a4d9524721d40ef9ee26f93f9bd6a51dba106f2
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -117,13 +117,13 @@ F sqlite3.1 6be1ad09113570e1fc8dcaff84c9b0b337db5ffc
 F sqlite3.pc.in ae6f59a76e862f5c561eb32a380228a02afc3cad
 F src/alter.c 280f5c04b11b492703a342222b3de0a999445280
 F src/analyze.c a425d62e8fa9ebcb4359ab84ff0c62c6563d2e2a
-F src/attach.c 12c6957996908edc31c96d7c68d4942c2474405f
+F src/attach.c a87bfb77a720f7aa02791434aacfd9bc8feb50cc
 F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
 F src/backup.c 986c15232757f2873dff35ee3b35cbf935fc573c
 F src/bitvec.c af50f1c8c0ff54d6bdb7a80e2fceca5a93670bef
 F src/btmutex.c 976f45a12e37293e32cae0281b15a21d48a8aaa7
 F src/btree.c 26f8a9d6169413c5682b89b5397d20437b653154
-F src/btree.h f5d775cd6cfc7ac32a2535b70e8d2af48ef5f2ce
+F src/btree.h d796dc4030b3cce7f5a0cc4f2f986d2befa6b8ac
 F src/btreeInt.h 67978c014fa4f7cc874032dd3aacadd8db656bc3
 F src/build.c 0132bc6631fa617a1d28ef805921f6dbac18a514
 F src/callback.c 0425c6320730e6d3981acfb9202c1bed9016ad1a
@@ -144,7 +144,7 @@ F src/journal.c 552839e54d1bf76fb8f7abe51868b66acacf6a0e
 F src/legacy.c a199d7683d60cef73089e892409113e69c23a99f
 F src/lempar.c 7f026423f4d71d989e719a743f98a1cbd4e6d99e
 F src/loadext.c 3ae0d52da013a6326310655be6473fd472347b85
-F src/main.c f00cee5a27f5df5ed536e7043cb451b3c85ce65c
+F src/main.c 167fb3285720917e4d1a5c633f558c81b751eca3
 F src/malloc.c 591aedb20ae40813f1045f2ef253438a334775d9
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c 00bd8265c81abb665c48fea1e0c234eb3b922206
@@ -165,8 +165,8 @@ F src/os_common.h a8f95b81eca8a1ab8593d23e94f8a35f35d4078f
 F src/os_os2.c 4a75888ba3dfc820ad5e8177025972d74d7f2440
 F src/os_unix.c 03630dd062c3d1fb9f25e2a227048b709c5babff
 F src/os_win.c ff0e14615a5086fa5ba6926e4ec0dc9cfb5a1a84
-F src/pager.c 24b689bc3639d534f5fb292d2c68038b1e720527
-F src/pager.h 3f8c783de1d4706b40b1ac15b64f5f896bcc78d1
+F src/pager.c 4056376f83f85cea9922a11161087c529e39f7dc
+F src/pager.h 34c6b029446f06f40847746d22faac0d354dd909
 F src/parse.y 12b7ebd61ea54f0e1b1083ff69cc2c8ce9353d58
 F src/pcache.c 09d38c44ab275db581f7a2f6ff8b9bc7f8c0faaa
 F src/pcache.h c683390d50f856d4cd8e24342ae62027d1bb6050
@@ -181,7 +181,7 @@ F src/select.c d9d440809025a58547e39f4f268c2a296bfb56ff
 F src/shell.c 72e7e176bf46d5c6518d15ac4ad6847c4bb5df79
 F src/sqlite.h.in e7bbcb330ced6b5e25c9db8089c2c77aaefadf7d
 F src/sqlite3ext.h c90bd5507099f62043832d73f6425d8d5c5da754
-F src/sqliteInt.h b34bd64a7ade4808fcc301e0bb67ef5051ea49c6
+F src/sqliteInt.h 798fb09648cefc159ac9b3ce5e00f5ada1377ed1
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac64842c86cec2fc1a1d0e5c16d3beb8ad332bf
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -245,8 +245,8 @@ F src/vdbeblob.c c3ccb7c8732858c680f442932e66ad06bb036562
 F src/vdbemem.c 0498796b6ffbe45e32960d6a1f5adfb6e419883b
 F src/vdbetrace.c 5d0dc3d5fd54878cc8d6d28eb41deb8d5885b114
 F src/vtab.c 48dcef8bc757c2e7b488f68b5ddebb1650da2450
-F src/wal.c 2574b16ee88b1934e97f63ae38025dc48ef45327
-F src/wal.h 7a5fbb00114b7f2cd40c7e1003d4c41ce9d26840
+F src/wal.c adc6c83b650e67e32159e11d557a46594834853e
+F src/wal.h c1e05cdf3d42ed7c9263739ca8f5cdd8761e7de3
 F src/walker.c 3112bb3afe1d85dc52317cb1d752055e9a781f8f
 F src/where.c 55403ce19c506be6a321c7f129aff693d6103db5
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
@@ -883,7 +883,7 @@ F test/walfault.test 58fce626359c9376fe35101b5c0f2df8040aa839
 F test/walhook.test ed00a40ba7255da22d6b66433ab61fab16a63483
 F test/walmode.test 22ddccd073c817ac9ead62b88ac446e8dedc7d2c
 F test/walnoshm.test a074428046408f4eb5c6a00e09df8cc97ff93317
-F test/walro.test 0fb4c79a9dfa1d14f46859e469d3b4844480cd9d
+F test/walro.test c204f62fb6a77839bc6ce5adbdcc9df2aac877ca
 F test/walshared.test 6dda2293880c300baf5d791c307f653094585761
 F test/walslow.test d21625e2e99e11c032ce949e8a94661576548933
 F test/walthread.test a25a393c068a2b42b44333fa3fdaae9072f1617c
@@ -936,10 +936,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P d9bc1c7fe0ca5f6973a85827330958f4d09f8171
-R 864e9c4ee7a6cf5f8240415fb38d1af8
-T *branch * wal-readonly
-T *sym-wal-readonly *
-T -sym-trunk *
+P bb59f9862da45d25fb51d7821130854828c91c98
+R 04ad06f1f1eb20213db6e513d8bb75aa
 U dan
-Z 321776a9f8d852e48652ad186c3a479b
+Z 112f0ce43ba9dc957c26d5146ee2fe50
diff --git a/manifest.uuid b/manifest.uuid
index e39ce5418f..e0664d4e86 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-bb59f9862da45d25fb51d7821130854828c91c98
\ No newline at end of file
+671ba5fc59f7a958e5a4138d2425b1173a442ad7
\ No newline at end of file
diff --git a/src/attach.c b/src/attach.c
index 18f8823b31..4b8ea77917 100644
--- a/src/attach.c
+++ b/src/attach.c
@@ -76,6 +76,8 @@ static void attachFunc(
   Db *aNew;
   char *zErrDyn = 0;
   sqlite3_vfs *pVfs;
+  const char *zVfs = db->pVfs->zName;       /* Name of default (main) VFS */
+  int btflags = 0;
 
   UNUSED_PARAMETER(NotUsed);
 
@@ -129,7 +131,7 @@ static void attachFunc(
   ** or may not be initialised.
   */
   flags = db->openFlags;
-  rc = sqlite3ParseUri(db->pVfs->zName, zFile, &flags, &pVfs, &zPath, &zErr);
+  rc = sqlite3ParseUri(zVfs, zFile, &flags, &btflags, &pVfs, &zPath, &zErr);
   if( rc!=SQLITE_OK ){
     if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
     sqlite3_result_error(context, zErr, -1);
@@ -138,7 +140,7 @@ static void attachFunc(
   }
   assert( pVfs );
   flags |= SQLITE_OPEN_MAIN_DB;
-  rc = sqlite3BtreeOpen(pVfs, zPath, db, &aNew->pBt, 0, flags);
+  rc = sqlite3BtreeOpen(pVfs, zPath, db, &aNew->pBt, btflags, flags);
   sqlite3_free( zPath );
   db->nDb++;
   if( rc==SQLITE_CONSTRAINT ){
diff --git a/src/btree.h b/src/btree.h
index 9e3a73b3b6..c5abc9c865 100644
--- a/src/btree.h
+++ b/src/btree.h
@@ -61,6 +61,7 @@ int sqlite3BtreeOpen(
 #define BTREE_MEMORY        4  /* This is an in-memory DB */
 #define BTREE_SINGLE        8  /* The file contains at most 1 b-tree */
 #define BTREE_UNORDERED    16  /* Use of a hash implementation is OK */
+#define BTREE_READONLYSHM  32  /* Read-only SHM access is acceptable */
 
 int sqlite3BtreeClose(Btree*);
 int sqlite3BtreeSetCacheSize(Btree*,int);
diff --git a/src/main.c b/src/main.c
index 5b46f4b736..e986f83225 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1818,6 +1818,7 @@ int sqlite3ParseUri(
   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
   const char *zUri,               /* Nul-terminated URI to parse */
   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
+  int *pBtflags,                  /* IN/OUT: BTREE_XXX flags */
   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */ 
   char **pzFile,                  /* OUT: Filename component of URI */
   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
@@ -1933,6 +1934,12 @@ int sqlite3ParseUri(
 
       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
         zVfs = zVal;
+      }else if( nOpt==12 && memcmp("readonly_shm", zOpt, 12)==0 ){
+        if( sqlite3Atoi(zVal) ){
+          *pBtflags |= BTREE_READONLYSHM;
+        }else{
+          *pBtflags &= ~BTREE_READONLYSHM;
+        }
       }else{
         struct OpenMode {
           const char *z;
@@ -2036,6 +2043,7 @@ static int openDatabase(
   int isThreadsafe;               /* True for threadsafe connections */
   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
+  int btflags = 0;                /* Mask of BTREE_XXX flags */
 
   *ppDb = 0;
 #ifndef SQLITE_OMIT_AUTOINIT
@@ -2163,7 +2171,8 @@ static int openDatabase(
                   nocaseCollatingFunc, 0);
 
   /* Parse the filename/URI argument. */
-  rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
+  rc = sqlite3ParseUri(
+      zVfs, zFilename, &flags, &btflags, &db->pVfs, &zOpen, &zErrMsg);
   if( rc!=SQLITE_OK ){
     if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
     sqlite3Error(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
@@ -2173,7 +2182,7 @@ static int openDatabase(
 
   /* Open the backend database driver */
   db->openFlags = flags;
-  rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
+  rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, btflags,
                         flags | SQLITE_OPEN_MAIN_DB);
   if( rc!=SQLITE_OK ){
     if( rc==SQLITE_IOERR_NOMEM ){
diff --git a/src/pager.c b/src/pager.c
index 8ad6984f8a..56dae06040 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -620,6 +620,7 @@ struct Pager {
   u8 tempFile;                /* zFilename is a temporary file */
   u8 readOnly;                /* True for a read-only database */
   u8 memDb;                   /* True to inhibit all file I/O */
+  u8 readOnlyShm;             /* True if read-only shm access is Ok */
 
   /**************************************************************************
   ** The following block contains those class members that change during
@@ -3017,6 +3018,7 @@ static int pagerWalFrames(
 static int pagerBeginReadTransaction(Pager *pPager){
   int rc;                         /* Return code */
   int changed = 0;                /* True if cache must be reset */
+  Wal *pWal = pPager->pWal;
 
   assert( pagerUseWal(pPager) );
   assert( pPager->eState==PAGER_OPEN || pPager->eState==PAGER_READER );
@@ -3026,9 +3028,9 @@ static int pagerBeginReadTransaction(Pager *pPager){
   ** are in locking_mode=NORMAL and EndRead() was previously called,
   ** the duplicate call is harmless.
   */
-  sqlite3WalEndReadTransaction(pPager->pWal);
+  sqlite3WalEndReadTransaction(pWal);
 
-  rc = sqlite3WalBeginReadTransaction(pPager->pWal, &changed);
+  rc = sqlite3WalBeginReadTransaction(pWal, pPager->readOnlyShm, &changed);
   if( rc!=SQLITE_OK || changed ){
     pager_reset(pPager);
   }
@@ -4414,6 +4416,7 @@ int sqlite3PagerOpen(
   }
   pPager->pVfs = pVfs;
   pPager->vfsFlags = vfsFlags;
+  pPager->readOnlyShm = (flags & PAGER_READONLYSHM)!=0;
 
   /* Open the pager file.
   */
diff --git a/src/pager.h b/src/pager.h
index eab7ddaf80..c6cb8bcb55 100644
--- a/src/pager.h
+++ b/src/pager.h
@@ -60,6 +60,7 @@ typedef struct PgHdr DbPage;
 #define PAGER_OMIT_JOURNAL  0x0001    /* Do not use a rollback journal */
 #define PAGER_NO_READLOCK   0x0002    /* Omit readlocks on readonly files */
 #define PAGER_MEMORY        0x0004    /* In-memory database */
+#define PAGER_READONLYSHM   0x0020    /* Read-only SHM access is acceptable */
 
 /*
 ** Valid values for the second argument to sqlite3PagerLockingMode().
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 4a3e45d7c0..cedd780779 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2673,7 +2673,7 @@ void sqlite3AddColumnType(Parse*,Token*);
 void sqlite3AddDefaultValue(Parse*,ExprSpan*);
 void sqlite3AddCollateType(Parse*, Token*);
 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
-int sqlite3ParseUri(const char*,const char*,unsigned int*,
+int sqlite3ParseUri(const char*,const char*,unsigned int*,int*,
                     sqlite3_vfs**,char**,char **);
 
 Bitvec *sqlite3BitvecCreate(u32);
diff --git a/src/wal.c b/src/wal.c
index 707fe12976..3d6baf21c8 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -529,7 +529,8 @@ static int walIndexPage(Wal *pWal, int iPage, volatile u32 **ppPage){
       rc = sqlite3OsShmMap(pWal->pDbFd, iPage, WALINDEX_PGSZ, 
           pWal->writeLock, (void volatile **)&pWal->apWiData[iPage]
       );
-      if( rc==SQLITE_CANTOPEN && iPage==0 ){
+      if( rc==SQLITE_CANTOPEN && pWal->readOnlyShm>1 ){
+        assert( iPage==0 );
         sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_READONLY_SHM, (void*)1);
         rc = sqlite3OsShmMap(pWal->pDbFd, iPage, WALINDEX_PGSZ, 
             pWal->writeLock, (void volatile **)&pWal->apWiData[iPage]
@@ -541,9 +542,10 @@ static int walIndexPage(Wal *pWal, int iPage, volatile u32 **ppPage){
       }
     }
   }
-
   *ppPage = pWal->apWiData[iPage];
+
   assert( iPage==0 || *ppPage || rc!=SQLITE_OK );
+  if( pWal->readOnlyShm>1 ) pWal->readOnlyShm = 0;
   return rc;
 }
 
@@ -1909,6 +1911,7 @@ static int walIndexReadHdr(Wal *pWal, int *pChanged){
     return rc;
   };
   assert( page0 || pWal->writeLock==0 );
+  assert( pWal->readOnlyShm==0 || pWal->readOnlyShm==1 );
 
   /* If the first page of the wal-index has been mapped, try to read the
   ** wal-index header immediately, without holding any lock. This usually
@@ -2200,13 +2203,18 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
 ** Pager layer will use this to know that is cache is stale and
 ** needs to be flushed.
 */
-int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){
+int sqlite3WalBeginReadTransaction(Wal *pWal, int readOnlyShm, int *pChanged){
   int rc;                         /* Return code */
   int cnt = 0;                    /* Number of TryBeginRead attempts */
 
+  if( pWal->nWiData==0 || pWal->apWiData[0]==0 ){
+    assert( readOnlyShm==0 || readOnlyShm==1 );
+    pWal->readOnlyShm = readOnlyShm*2;
+  }
   do{
     rc = walTryBeginRead(pWal, pChanged, 0, ++cnt);
   }while( rc==WAL_RETRY );
+  assert( rc || pWal->readOnlyShm==0 || (readOnlyShm && pWal->readOnlyShm==1) );
   testcase( (rc&0xff)==SQLITE_BUSY );
   testcase( (rc&0xff)==SQLITE_IOERR );
   testcase( rc==SQLITE_PROTOCOL );
diff --git a/src/wal.h b/src/wal.h
index 2039c701cf..aca5a56a56 100644
--- a/src/wal.h
+++ b/src/wal.h
@@ -22,7 +22,7 @@
 #ifdef SQLITE_OMIT_WAL
 # define sqlite3WalOpen(x,y,z)                   0
 # define sqlite3WalClose(w,x,y,z)                0
-# define sqlite3WalBeginReadTransaction(y,z)     0
+# define sqlite3WalBeginReadTransaction(x,y,z)   0
 # define sqlite3WalEndReadTransaction(z)
 # define sqlite3WalRead(v,w,x,y,z)               0
 # define sqlite3WalDbsize(y)                     0
@@ -56,7 +56,7 @@ int sqlite3WalClose(Wal *pWal, int sync_flags, int, u8 *);
 ** write to or checkpoint the WAL.  sqlite3WalCloseSnapshot() closes the
 ** transaction and releases the lock.
 */
-int sqlite3WalBeginReadTransaction(Wal *pWal, int *);
+int sqlite3WalBeginReadTransaction(Wal *pWal, int, int *);
 void sqlite3WalEndReadTransaction(Wal *pWal);
 
 /* Read a page from the write-ahead log, if it is present. */
diff --git a/test/walro.test b/test/walro.test
index b558622cad..1025f00e33 100644
--- a/test/walro.test
+++ b/test/walro.test
@@ -35,6 +35,13 @@ do_multiclient_test tn {
   forcedelete test.db
   forcedelete walro
 
+  foreach c {code1 code2 code3} {
+    $c {
+      sqlite3_shutdown
+      sqlite3_config_uri 1
+    }
+  }
+
   file mkdir walro
 
   do_test 1.1.1 {
@@ -49,7 +56,7 @@ do_multiclient_test tn {
 
   do_test 1.1.2 {
     file attributes test.db-shm -permissions r--r--r--
-    code1 { sqlite3 db test.db }
+    code1 { sqlite3 db file:test.db?readonly_shm=1 }
   } {}
 
   do_test 1.1.3 { sql1 "SELECT * FROM t1" }                {a b}
@@ -84,7 +91,7 @@ do_multiclient_test tn {
     list [file exists test.db-wal] [file exists test.db-shm]
   } {1 1}
   do_test 1.2.2 {
-    code1 { sqlite3 db test.db }
+    code1 { sqlite3 db file:test.db?readonly_shm=1 }
     sql1 { SELECT * FROM t1 }
   } {a b c d e f g h i j}
 
@@ -93,7 +100,7 @@ do_multiclient_test tn {
     file attributes test.db-shm -permissions rw-r--r--
     hexio_write test.db-shm 0 01020304 
     file attributes test.db-shm -permissions r--r--r--
-    code1 { sqlite3 db test.db }
+    code1 { sqlite3 db file:test.db?readonly_shm=1 }
     csql1 { SELECT * FROM t1 }
   } {1 {attempt to write a readonly database}}
   do_test 1.2.4 {

From a96a399ec95667f268c135e74a16bef517b1fca2 Mon Sep 17 00:00:00 2001
From: dan <dan@noemail.net>
Date: Wed, 11 May 2011 17:36:17 +0000
Subject: [PATCH 03/30] Add missing comments associated with readonly shm
 changes.

FossilOrigin-Name: 6a2ea52e6c09a570428161090c2f087c66f714ec
---
 manifest        | 16 ++++++++--------
 manifest.uuid   |  2 +-
 src/main.c      |  5 +++++
 src/sqlite.h.in | 39 ++++++++++++++++++++++++++++++++++++++-
 src/wal.c       |  8 ++++++++
 5 files changed, 60 insertions(+), 10 deletions(-)

diff --git a/manifest b/manifest
index d15e2a3497..15dda4253a 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Merge\slatest\strunk\schanges.\sAdd\sa\scouple\sof\sreadonly\sshm\stests.
-D 2011-05-11T15:53:16.929
+C Add\smissing\scomments\sassociated\swith\sreadonly\sshm\schanges.
+D 2011-05-11T17:36:17.276
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 7a4d9524721d40ef9ee26f93f9bd6a51dba106f2
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -144,7 +144,7 @@ F src/journal.c 552839e54d1bf76fb8f7abe51868b66acacf6a0e
 F src/legacy.c a199d7683d60cef73089e892409113e69c23a99f
 F src/lempar.c 7f026423f4d71d989e719a743f98a1cbd4e6d99e
 F src/loadext.c 3ae0d52da013a6326310655be6473fd472347b85
-F src/main.c 951a1af49d13083da09be9d2464052e49fc25830
+F src/main.c a145cea130adfe945ab1fa7e9543c492e3f2f419
 F src/malloc.c 591aedb20ae40813f1045f2ef253438a334775d9
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c 00bd8265c81abb665c48fea1e0c234eb3b922206
@@ -179,7 +179,7 @@ F src/resolve.c 1c0f32b64f8e3f555fe1f732f9d6f501a7f05706
 F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
 F src/select.c d9d440809025a58547e39f4f268c2a296bfb56ff
 F src/shell.c 72e7e176bf46d5c6518d15ac4ad6847c4bb5df79
-F src/sqlite.h.in 059514ec27c8f9e11c73695aa57e55d354973e1e
+F src/sqlite.h.in adeb2c8019a3851a10e3872f44b34c95c6e409f2
 F src/sqlite3ext.h c90bd5507099f62043832d73f6425d8d5c5da754
 F src/sqliteInt.h 798fb09648cefc159ac9b3ce5e00f5ada1377ed1
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
@@ -245,7 +245,7 @@ F src/vdbeblob.c c3ccb7c8732858c680f442932e66ad06bb036562
 F src/vdbemem.c 0498796b6ffbe45e32960d6a1f5adfb6e419883b
 F src/vdbetrace.c 5d0dc3d5fd54878cc8d6d28eb41deb8d5885b114
 F src/vtab.c 48dcef8bc757c2e7b488f68b5ddebb1650da2450
-F src/wal.c adc6c83b650e67e32159e11d557a46594834853e
+F src/wal.c 6d8ee757f62bca9b0b713724677878dff5bf7e79
 F src/wal.h c1e05cdf3d42ed7c9263739ca8f5cdd8761e7de3
 F src/walker.c 3112bb3afe1d85dc52317cb1d752055e9a781f8f
 F src/where.c 55403ce19c506be6a321c7f129aff693d6103db5
@@ -936,7 +936,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 671ba5fc59f7a958e5a4138d2425b1173a442ad7 3e490915301216e242a5cdeb0febaff12ed53cb9
-R 1feba9025b47c541dc5cefaffc74e97e
+P cde45a033ee6834900f5f5c272c383408883a74c
+R 77f3671cb0a1ec2771484489a2a100be
 U dan
-Z af31082504210cb42f7a67f58917a8ef
+Z 826df29e354d14eb64673fd89c39c62e
diff --git a/manifest.uuid b/manifest.uuid
index 8bb70d0669..68e3f5666d 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-cde45a033ee6834900f5f5c272c383408883a74c
\ No newline at end of file
+6a2ea52e6c09a570428161090c2f087c66f714ec
\ No newline at end of file
diff --git a/src/main.c b/src/main.c
index 45ee8fbd5b..f4cf735e3c 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1803,6 +1803,11 @@ int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
 ** *pFlags may be updated before returning if the URI filename contains 
 ** "cache=xxx" or "mode=xxx" query parameters.
 **
+** The third argument, pBtflags, points to an integer containing the flags
+** that will be passed as the 5th argument to sqlite3BtreeOpen (BTREE_XXX
+** flags). This value will be edited if the URI filename contains a
+** "readonly_shm=1" or "readonly_shm=0" query parameter.
+**
 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
 ** the VFS that should be used to open the database file. *pzFile is set to
 ** point to a buffer containing the name of the file to open. It is the 
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index bafd322264..a002a8b4ea 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -736,6 +736,27 @@ struct sqlite3_io_methods {
 ** Applications should not call [sqlite3_file_control()] with this
 ** opcode as doing so may disrupt the operation of the specialized VFSes
 ** that do require it.  
+**
+** The [SQLITE_FCNTL_READONLY_SHM] may be generated internally by SQLite if
+** the "readonly_shm=1" URI option is specified when the database is opened.
+** The fourth argument passed to the VFS xFileControl methods is a pointer
+** to a variable of type "int" containing the value 1 or 0. If the variable
+** contains the value 1, then this indicates to the VFS that a read-only
+** mapping of the shared-memory region is acceptable. If it is set to 0, then
+** this indicates that a read-write mapping is required (as normal). If
+** a read-only mapping is returned, then the VFS may also return read-only
+** mappings for any subsequent requests via the same file-descriptor -
+** regardless of the value most recently configured using
+** SQLITE_FCNTL_READONLY_SHM.
+**
+** In practice, if "readonly_shm=1" is specified and the first attempt to
+** map a shared-memory region fails, then this file-control is invoked with
+** the argument variable set to 1 and a second attempt to map the shared-memory
+** region is made. If this mapping succeeds, then the connection continues
+** with the read-only mapping. Otherwise, if it fails, SQLITE_CANTOPEN is
+** returned to the caller. Whether or not the second (read-only) mapping
+** attempt succeeds, the file-control is invoked again with the argument
+** variable set to 0.
 */
 #define SQLITE_FCNTL_LOCKSTATE        1
 #define SQLITE_GET_LOCKPROXYFILE      2
@@ -2444,7 +2465,7 @@ void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
 **
 ** The query component of a URI may contain parameters that are interpreted
 ** either by SQLite itself, or by a [sqlite3_vfs | custom VFS implementation].
-** SQLite interprets the following three query parameters:
+** SQLite interprets the following four query parameters:
 **
 ** <ul>
 **   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
@@ -2476,6 +2497,22 @@ void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
 **     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
 **     a URI filename, its value overrides any behaviour requested by setting
 **     SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
+**
+**   <li> <b>readonly_shm</b>: ^The readonly_shm parameter may be set to 
+**     either "1" or "0". Setting it to "1" indicates that if the database
+**     is in WAL mode and read-write access to the associated shared 
+**     memory region cannot be obtained, then an attempt should be made to open
+**     the shared-memory in read-only mode instead. If there exist one or
+**     more other database clients that have read-write connections to the
+**     database shared-memory, then a read-only shared-memory connection works 
+**     fine. However, if there exist no clients with read-write connections 
+**     to the shared-memory and the most recent such crashed or was interrupted
+**     by a power failure, then it is possible for a database client using a
+**     read-only connection to return incorrect data, incorrectly report 
+**     database corruption, or return an SQLITE_READONLY error. Or if the
+**     most recent read-write connection shut down cleanly, it may not be
+**     possible to open the shared-memory in read-only mode at all, and SQLite
+**     will return SQLITE_CANTOPEN.
 ** </ul>
 **
 ** ^Specifying an unknown parameter in the query component of a URI is not an
diff --git a/src/wal.c b/src/wal.c
index 3d6baf21c8..2ee7f59e89 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -406,6 +406,14 @@ struct WalCkptInfo {
 /*
 ** An open write-ahead log file is represented by an instance of the
 ** following object.
+**
+** The readOnlyShm variable is normally set to 0. If it is set to 1, then
+** the connection to shared-memory is read-only. This means it cannot
+** be written at all (even when read-locking the database). If it is set
+** to 2, then the shared-memory region is not yet open, but a read-only
+** connection is acceptable. In this case when the shared-memory is opened
+** (see function walIndexPage()), readOnlyShm is set to either 0 or 1 as
+** appropriate.
 */
 struct Wal {
   sqlite3_vfs *pVfs;         /* The VFS used to create pDbFd */

From ef05c39d12cf13bdad52c9f63f3154a588aaeb74 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Wed, 25 May 2011 20:25:10 +0000
Subject: [PATCH 04/30] Ignore malloc failures within the WAL file truncation
 attempt for journal_size_limit.

FossilOrigin-Name: dd19105aa9521ffc0edcf16b84c064d5ebad55d7
---
 manifest      | 14 +++++++-------
 manifest.uuid |  2 +-
 src/wal.c     |  2 ++
 3 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/manifest b/manifest
index 1074285b3f..bd65c3d5e3 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sa\scase\swhere\sa\smalloc()\serror\scould\slead\sto\smismatched\svirtual-table\sxBegin/xCommit/xRollback\scallbacks.
-D 2011-05-25T18:46:22.024
+C Ignore\smalloc\sfailures\swithin\sthe\sWAL\sfile\struncation\sattempt\sfor\njournal_size_limit.
+D 2011-05-25T20:25:10.559
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -245,7 +245,7 @@ F src/vdbeblob.c c3ccb7c8732858c680f442932e66ad06bb036562
 F src/vdbemem.c 0498796b6ffbe45e32960d6a1f5adfb6e419883b
 F src/vdbetrace.c 5d0dc3d5fd54878cc8d6d28eb41deb8d5885b114
 F src/vtab.c 9ba8c7fdb7d39260c033a402f6032d3e7bc5d336
-F src/wal.c de27c34c8016c00be348fc6bed588816557ceb66
+F src/wal.c ab1d8c5abf904fd6396f90499cbd8c54b8d6961b
 F src/wal.h 66b40bd91bc29a5be1c88ddd1f5ade8f3f48728a
 F src/walker.c 3112bb3afe1d85dc52317cb1d752055e9a781f8f
 F src/where.c 55403ce19c506be6a321c7f129aff693d6103db5
@@ -938,7 +938,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 6df99e52dabf2a243ad635529649b86c21735e91
-R 02c26b8fd230a540c57276590c974e79
-U dan
-Z e2a23225f8e5abceac6a8fe1d14982ec
+P d807304a695fc85402b86e1cd32a6e3bbb2823c8
+R 40f4c0754c95b7a51c08aa03886ff26c
+U drh
+Z c74bad4333e073e26c4db5e166f8f584
diff --git a/manifest.uuid b/manifest.uuid
index 5b49fb4d2d..f139bfb8f7 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-d807304a695fc85402b86e1cd32a6e3bbb2823c8
\ No newline at end of file
+dd19105aa9521ffc0edcf16b84c064d5ebad55d7
\ No newline at end of file
diff --git a/src/wal.c b/src/wal.c
index 1222660985..d90fb05d8b 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -2539,10 +2539,12 @@ static int walRestartLog(Wal *pWal){
         if( pWal->mxWalSize>=0 ){
           i64 sz;
           int rx;
+          sqlite3BeginBenignMalloc();
           rx = sqlite3OsFileSize(pWal->pWalFd, &sz);
           if( rx==SQLITE_OK && (sz > pWal->mxWalSize) ){
             rx = sqlite3OsTruncate(pWal->pWalFd, pWal->mxWalSize);
           }
+          sqlite3EndBenignMalloc();
           if( rx ){
             sqlite3_log(rx, "cannot limit WAL size: %s", pWal->zWalName);
           }

From 7ee4fdd7ba0366a929adb5c94297f9debcf4a4b3 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Wed, 25 May 2011 23:18:02 +0000
Subject: [PATCH 05/30] Fix some minor and harmless compiler warnings.

FossilOrigin-Name: a4755e7088c3cc7c5ea191ce37f3950472f523ec
---
 ext/fts3/fts3.c     |  4 ++++
 ext/fts3/fts3_aux.c |  6 +++++-
 ext/rtree/rtree.c   |  7 +++++--
 manifest            | 16 ++++++++--------
 manifest.uuid       |  2 +-
 5 files changed, 23 insertions(+), 12 deletions(-)

diff --git a/ext/fts3/fts3.c b/ext/fts3/fts3.c
index 5e2472753e..0aba0546c3 100644
--- a/ext/fts3/fts3.c
+++ b/ext/fts3/fts3.c
@@ -3665,6 +3665,7 @@ static int fts3RenameMethod(
 
 static int fts3SavepointMethod(sqlite3_vtab *pVtab, int iSavepoint){
   Fts3Table *p = (Fts3Table*)pVtab;
+  UNUSED_PARAMETER(iSavepoint);
   assert( p->inTransaction );
   assert( p->mxSavepoint < iSavepoint );
   TESTONLY( p->mxSavepoint = iSavepoint );
@@ -3672,6 +3673,8 @@ static int fts3SavepointMethod(sqlite3_vtab *pVtab, int iSavepoint){
 }
 static int fts3ReleaseMethod(sqlite3_vtab *pVtab, int iSavepoint){
   TESTONLY( Fts3Table *p = (Fts3Table*)pVtab );
+  UNUSED_PARAMETER(iSavepoint);
+  UNUSED_PARAMETER(pVtab);
   assert( p->inTransaction );
   assert( p->mxSavepoint >= iSavepoint );
   TESTONLY( p->mxSavepoint = iSavepoint-1 );
@@ -3679,6 +3682,7 @@ static int fts3ReleaseMethod(sqlite3_vtab *pVtab, int iSavepoint){
 }
 static int fts3RollbackToMethod(sqlite3_vtab *pVtab, int iSavepoint){
   Fts3Table *p = (Fts3Table*)pVtab;
+  UNUSED_PARAMETER(iSavepoint);
   assert( p->inTransaction );
   assert( p->mxSavepoint >= iSavepoint );
   TESTONLY( p->mxSavepoint = iSavepoint );
diff --git a/ext/fts3/fts3_aux.c b/ext/fts3/fts3_aux.c
index 6108689ae1..cd035d2a30 100644
--- a/ext/fts3/fts3_aux.c
+++ b/ext/fts3/fts3_aux.c
@@ -342,6 +342,7 @@ static int fts3auxFilterMethod(
   int isScan;
 
   UNUSED_PARAMETER(nVal);
+  UNUSED_PARAMETER(idxStr);
 
   assert( idxStr==0 );
   assert( idxNum==FTS4AUX_EQ_CONSTRAINT || idxNum==0
@@ -459,7 +460,10 @@ int sqlite3Fts3InitAux(sqlite3 *db){
      0,                           /* xCommit       */
      0,                           /* xRollback     */
      0,                           /* xFindFunction */
-     0                            /* xRename       */
+     0,                           /* xRename       */
+     0,                           /* xSavepoint    */
+     0,                           /* xRelease      */
+     0                            /* xRollbackTo   */
   };
   int rc;                         /* Return code */
 
diff --git a/ext/rtree/rtree.c b/ext/rtree/rtree.c
index 6e00827b46..66a10df1c3 100644
--- a/ext/rtree/rtree.c
+++ b/ext/rtree/rtree.c
@@ -2849,7 +2849,7 @@ static int rtreeRename(sqlite3_vtab *pVtab, const char *zNewName){
 }
 
 static sqlite3_module rtreeModule = {
-  0,                         /* iVersion */
+  0,                          /* iVersion */
   rtreeCreate,                /* xCreate - create a table */
   rtreeConnect,               /* xConnect - connect to an existing table */
   rtreeBestIndex,             /* xBestIndex - Determine search strategy */
@@ -2868,7 +2868,10 @@ static sqlite3_module rtreeModule = {
   0,                          /* xCommit - commit transaction */
   0,                          /* xRollback - rollback transaction */
   0,                          /* xFindFunction - function overloading */
-  rtreeRename                 /* xRename - rename the table */
+  rtreeRename,                /* xRename - rename the table */
+  0,                          /* xSavepoint */
+  0,                          /* xRelease */
+  0                           /* xRollbackTo */
 };
 
 static int rtreeSqlInit(
diff --git a/manifest b/manifest
index bd65c3d5e3..bd8d6e5ef2 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Ignore\smalloc\sfailures\swithin\sthe\sWAL\sfile\struncation\sattempt\sfor\njournal_size_limit.
-D 2011-05-25T20:25:10.559
+C Fix\ssome\sminor\sand\sharmless\scompiler\swarnings.
+D 2011-05-25T23:18:02.794
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -61,10 +61,10 @@ F ext/fts2/mkfts2amal.tcl 974d5d438cb3f7c4a652639262f82418c1e4cff0
 F ext/fts3/README.syntax a19711dc5458c20734b8e485e75fb1981ec2427a
 F ext/fts3/README.tokenizers 998756696647400de63d5ba60e9655036cb966e9
 F ext/fts3/README.txt 8c18f41574404623b76917b9da66fcb0ab38328d
-F ext/fts3/fts3.c 0a2ae110f2d1806687ee0de837ac1eff106843b4
+F ext/fts3/fts3.c b3a10a1a320aaeb56a1dd6710bf09eb5c2370839
 F ext/fts3/fts3.h 3a10a0af180d502cecc50df77b1b22df142817fe
 F ext/fts3/fts3Int.h c8c0011c5e5b3a7703376ea6cd7deb91cfb96a06
-F ext/fts3/fts3_aux.c 9e931f55eed8498dafe7bc1160f10cbb1a652fdf
+F ext/fts3/fts3_aux.c 97c960b1b0d371c08eae6b8565dfac619eb9d979
 F ext/fts3/fts3_expr.c 5f49e0deaf723724b08100bb3ff40aab02ad0c93
 F ext/fts3/fts3_hash.c 3c8f6387a4a7f5305588b203fa7c887d753e1f1c
 F ext/fts3/fts3_hash.h 8331fb2206c609f9fc4c4735b9ab5ad6137c88ec
@@ -82,7 +82,7 @@ F ext/icu/README.txt bf8461d8cdc6b8f514c080e4e10dc3b2bbdfefa9
 F ext/icu/icu.c eb9ae1d79046bd7871aa97ee6da51eb770134b5a
 F ext/icu/sqliteicu.h 728867a802baa5a96de7495e9689a8e01715ef37
 F ext/rtree/README 6315c0d73ebf0ec40dedb5aa0e942bc8b54e3761
-F ext/rtree/rtree.c 2445bec932f58f8f4fe9de49a63bd6bf24db82d6
+F ext/rtree/rtree.c 4b8438444927191b55de18e00df43b2e02aacbda
 F ext/rtree/rtree.h 834dbcb82dc85b2481cde6a07cdadfddc99e9b9e
 F ext/rtree/rtree1.test 28e1b8da4da98093ce3210187434dd760a8d89d8
 F ext/rtree/rtree2.test acbb3a4ce0f4fbc2c304d2b4b784cfa161856bba
@@ -938,7 +938,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P d807304a695fc85402b86e1cd32a6e3bbb2823c8
-R 40f4c0754c95b7a51c08aa03886ff26c
+P dd19105aa9521ffc0edcf16b84c064d5ebad55d7
+R 008aea5da6bfc4eb7e4a2c09eb3620eb
 U drh
-Z c74bad4333e073e26c4db5e166f8f584
+Z e8c2f21e52caf9d88919dc2348e8bfe9
diff --git a/manifest.uuid b/manifest.uuid
index f139bfb8f7..310e58b317 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-dd19105aa9521ffc0edcf16b84c064d5ebad55d7
\ No newline at end of file
+a4755e7088c3cc7c5ea191ce37f3950472f523ec
\ No newline at end of file

From 305ebab7cc7b12e17a502865a01c9d20658495fe Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Thu, 26 May 2011 14:19:14 +0000
Subject: [PATCH 06/30] Changes to work with SQLITE_OMIT_VIRTUAL_TABLE.

FossilOrigin-Name: 03f7d36a8a24825b7542b5fed651af1622ae4eb5
---
 manifest                | 14 +++++++-------
 manifest.uuid           |  2 +-
 src/vdbe.c              |  2 ++
 test/tkt-2d1a5c67d.test |  2 +-
 4 files changed, 11 insertions(+), 9 deletions(-)

diff --git a/manifest b/manifest
index bd8d6e5ef2..3f4e379ddd 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\ssome\sminor\sand\sharmless\scompiler\swarnings.
-D 2011-05-25T23:18:02.794
+C Changes\sto\swork\swith\sSQLITE_OMIT_VIRTUAL_TABLE.
+D 2011-05-26T14:19:14.865
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -236,7 +236,7 @@ F src/update.c 5bcb56e5c7380a2eecb0e71891dbd4ad7437748f
 F src/utf.c d83650c3ea08f7407bd9d0839d9885241c209c60
 F src/util.c 0f33bbbdfcc4a2d8cf20c3b2a16ffc3b57c58a70
 F src/vacuum.c 05513dca036a1e7848fe18d5ed1265ac0b32365e
-F src/vdbe.c 4812f0e5813b3969307ec466d26d9b32b7b814e9
+F src/vdbe.c a8ff6724d4f1ca8c45ef778d67633d1fb4d9bdbf
 F src/vdbe.h 8a675fefdf7119441fe817c800a9a52440c2e797
 F src/vdbeInt.h fe8f58d305e629fff02f61f655aca1d299f1f6ae
 F src/vdbeapi.c e0e2672e0a96ae3f8575c8ecd02912a3e8a554a1
@@ -705,7 +705,7 @@ F test/threadtest2.c ace893054fa134af3fc8d6e7cfecddb8e3acefb9
 F test/threadtest3.c 0ed13e09690f6204d7455fac3b0e8ece490f6eef
 F test/tkt-02a8e81d44.test 58494de77be2cf249228ada3f313fa399821c6ab
 F test/tkt-26ff0c2d1e.test 888324e751512972c6e0d1a09df740d8f5aaf660
-F test/tkt-2d1a5c67d.test 450b3cf86ca9a3b1fd0a9e136978142be3bff7e0
+F test/tkt-2d1a5c67d.test 73574c758502bf23260c17f97fcd9316dfb5a060
 F test/tkt-2ea2425d34.test 1cf13e6f75d149b3209a0cb32927a82d3d79fb28
 F test/tkt-31338dca7e.test 5741cd48de500347a437ba1be58c8335e83c5a5e
 F test/tkt-313723c356.test c47f8a9330523e6f35698bf4489bcb29609b53ac
@@ -938,7 +938,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P dd19105aa9521ffc0edcf16b84c064d5ebad55d7
-R 008aea5da6bfc4eb7e4a2c09eb3620eb
+P a4755e7088c3cc7c5ea191ce37f3950472f523ec
+R 730ee7bc721983cbb8520125b21bb17e
 U drh
-Z e8c2f21e52caf9d88919dc2348e8bfe9
+Z d447764bdbeb7397b78d42ae4b389d7c
diff --git a/manifest.uuid b/manifest.uuid
index 310e58b317..ff053854df 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-a4755e7088c3cc7c5ea191ce37f3950472f523ec
\ No newline at end of file
+03f7d36a8a24825b7542b5fed651af1622ae4eb5
\ No newline at end of file
diff --git a/src/vdbe.c b/src/vdbe.c
index add643f176..c55927e663 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -2584,6 +2584,7 @@ case OP_Savepoint: {
     }else{
       nName = sqlite3Strlen30(zName);
 
+#ifdef SQLITE_OMIT_VIRTUAL_TABLE
       /* This call is Ok even if this savepoint is actually a transaction
       ** savepoint (and therefore should not prompt xSavepoint()) callbacks.
       ** If this is a transaction savepoint being opened, it is guaranteed
@@ -2592,6 +2593,7 @@ case OP_Savepoint: {
       rc = sqlite3VtabSavepoint(db, SAVEPOINT_BEGIN,
                                 db->nStatement+db->nSavepoint);
       if( rc!=SQLITE_OK ) goto abort_due_to_error;
+#endif
 
       /* Create a new savepoint structure. */
       pNew = sqlite3DbMallocRaw(db, sizeof(Savepoint)+nName+1);
diff --git a/test/tkt-2d1a5c67d.test b/test/tkt-2d1a5c67d.test
index 5db364bd79..278e1d38bc 100644
--- a/test/tkt-2d1a5c67d.test
+++ b/test/tkt-2d1a5c67d.test
@@ -19,7 +19,7 @@ set testdir [file dirname $argv0]
 source $testdir/tester.tcl
 set testprefix tkt-2d1a5c67d
 
-ifcapable !wal {finish_test; return}
+ifcapable {!wal || !vtab} {finish_test; return}
 
 for {set ii 1} {$ii<=10} {incr ii} {
   do_test tkt-2d1a5c67d.1.$ii {

From c97125eb72437be15c8499782bb00c786671cd4a Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Sat, 28 May 2011 15:53:07 +0000
Subject: [PATCH 07/30] Print a log message on each cache spill if compiled
 with SQLITE_LOG_CACHE_SPILL.

FossilOrigin-Name: 5f15579f8ca747f0fa0a7867ceffc8c7b8f904e6
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/pcache.c  |  7 +++++++
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/manifest b/manifest
index 3f4e379ddd..ef773de94f 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Changes\sto\swork\swith\sSQLITE_OMIT_VIRTUAL_TABLE.
-D 2011-05-26T14:19:14.865
+C Print\sa\slog\smessage\son\seach\scache\sspill\sif\scompiled\swith\nSQLITE_LOG_CACHE_SPILL.
+D 2011-05-28T15:53:07.056
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -168,7 +168,7 @@ F src/os_win.c 218b899469e570d46eb8147c2383075f7c026230
 F src/pager.c 120550e7ef01dafaa2cbb4a0528c0d87c8f12b41
 F src/pager.h 3f8c783de1d4706b40b1ac15b64f5f896bcc78d1
 F src/parse.y 12b7ebd61ea54f0e1b1083ff69cc2c8ce9353d58
-F src/pcache.c 09d38c44ab275db581f7a2f6ff8b9bc7f8c0faaa
+F src/pcache.c 49e718c095810c6b3334e3a6d89970aceaddefce
 F src/pcache.h c683390d50f856d4cd8e24342ae62027d1bb6050
 F src/pcache1.c d548e31beafa792d1994b663a29a5303569efc4e
 F src/pragma.c 9e778decc3ee9bcaf88904b4a3b0a4360aaf0eab
@@ -938,7 +938,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P a4755e7088c3cc7c5ea191ce37f3950472f523ec
-R 730ee7bc721983cbb8520125b21bb17e
+P 03f7d36a8a24825b7542b5fed651af1622ae4eb5
+R ecca10c4aa82cb4b740a494236bdb180
 U drh
-Z d447764bdbeb7397b78d42ae4b389d7c
+Z 7233c15025f0530a32ecee3359d1f724
diff --git a/manifest.uuid b/manifest.uuid
index ff053854df..42def11d4f 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-03f7d36a8a24825b7542b5fed651af1622ae4eb5
\ No newline at end of file
+5f15579f8ca747f0fa0a7867ceffc8c7b8f904e6
\ No newline at end of file
diff --git a/src/pcache.c b/src/pcache.c
index 242f3071d9..f37511e9e4 100644
--- a/src/pcache.c
+++ b/src/pcache.c
@@ -253,6 +253,13 @@ int sqlite3PcacheFetch(
     }
     if( pPg ){
       int rc;
+#ifdef SQLITE_LOG_CACHE_SPILL
+      sqlite3_log(SQLITE_FULL, 
+                  "spill page %d making room for %d - cache used: %d/%d",
+                  pPg->pgno, pgno,
+                  sqlite3GlobalConfig.pcache.xPagecount(pCache->pCache),
+                  pCache->nMax);
+#endif
       rc = pCache->xStress(pCache->pStress, pPg);
       if( rc!=SQLITE_OK && rc!=SQLITE_BUSY ){
         return rc;

From 21f80f0478ae4570dfd9f803fecd15a05abc5b54 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Sat, 28 May 2011 19:24:15 +0000
Subject: [PATCH 08/30] Fix a "#ifdef" from check-in [03f7d36a8a] that should
 have been "#ifndef".

FossilOrigin-Name: edb865c35415f9553f8279028120f7b8de2bf7e2
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/vdbe.c    |  2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/manifest b/manifest
index ef773de94f..701dc47e95 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Print\sa\slog\smessage\son\seach\scache\sspill\sif\scompiled\swith\nSQLITE_LOG_CACHE_SPILL.
-D 2011-05-28T15:53:07.056
+C Fix\sa\s"#ifdef"\sfrom\scheck-in\s[03f7d36a8a]\sthat\sshould\shave\sbeen\s"#ifndef".
+D 2011-05-28T19:24:15.852
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -236,7 +236,7 @@ F src/update.c 5bcb56e5c7380a2eecb0e71891dbd4ad7437748f
 F src/utf.c d83650c3ea08f7407bd9d0839d9885241c209c60
 F src/util.c 0f33bbbdfcc4a2d8cf20c3b2a16ffc3b57c58a70
 F src/vacuum.c 05513dca036a1e7848fe18d5ed1265ac0b32365e
-F src/vdbe.c a8ff6724d4f1ca8c45ef778d67633d1fb4d9bdbf
+F src/vdbe.c 380dddc404c1e4a9260a4194daa728b94ed102d7
 F src/vdbe.h 8a675fefdf7119441fe817c800a9a52440c2e797
 F src/vdbeInt.h fe8f58d305e629fff02f61f655aca1d299f1f6ae
 F src/vdbeapi.c e0e2672e0a96ae3f8575c8ecd02912a3e8a554a1
@@ -938,7 +938,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 03f7d36a8a24825b7542b5fed651af1622ae4eb5
-R ecca10c4aa82cb4b740a494236bdb180
+P 5f15579f8ca747f0fa0a7867ceffc8c7b8f904e6
+R a63903941bea8f77658823b8763468e2
 U drh
-Z 7233c15025f0530a32ecee3359d1f724
+Z 62e9bfe1cc7669e25feec8cecb39066d
diff --git a/manifest.uuid b/manifest.uuid
index 42def11d4f..60ef9e438e 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-5f15579f8ca747f0fa0a7867ceffc8c7b8f904e6
\ No newline at end of file
+edb865c35415f9553f8279028120f7b8de2bf7e2
\ No newline at end of file
diff --git a/src/vdbe.c b/src/vdbe.c
index c55927e663..d28f73d1b1 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -2584,7 +2584,7 @@ case OP_Savepoint: {
     }else{
       nName = sqlite3Strlen30(zName);
 
-#ifdef SQLITE_OMIT_VIRTUAL_TABLE
+#ifndef SQLITE_OMIT_VIRTUAL_TABLE
       /* This call is Ok even if this savepoint is actually a transaction
       ** savepoint (and therefore should not prompt xSavepoint()) callbacks.
       ** If this is a transaction savepoint being opened, it is guaranteed

From 1fbb230f90e150c3c42c294afc06eb32901193e5 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Mon, 30 May 2011 14:35:48 +0000
Subject: [PATCH 09/30] Make sure the P5 argument to the OP_VUpdate opcode is
 always set to a valid conflict resolution code.

FossilOrigin-Name: e3350dbd9f472c27ea6bc872d85098ac89d874c7
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/delete.c  |  1 +
 3 files changed, 8 insertions(+), 7 deletions(-)

diff --git a/manifest b/manifest
index 701dc47e95..f9e0a1ae94 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sa\s"#ifdef"\sfrom\scheck-in\s[03f7d36a8a]\sthat\sshould\shave\sbeen\s"#ifndef".
-D 2011-05-28T19:24:15.852
+C Make\ssure\sthe\sP5\sargument\sto\sthe\sOP_VUpdate\sopcode\sis\salways\sset\sto\sa\nvalid\sconflict\sresolution\scode.
+D 2011-05-30T14:35:48.783
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -130,7 +130,7 @@ F src/callback.c 0425c6320730e6d3981acfb9202c1bed9016ad1a
 F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c 7deec4534f3b5a0c3b4a4cbadf809d321f64f9c4
 F src/date.c 1548fdac51377e4e7833251de878b4058c148e1b
-F src/delete.c 7a24fcc9a31664d145acb97ce56b6d9f249a25e4
+F src/delete.c cecc926c70783452f3e8eb452c728291ce1a0b21
 F src/expr.c e3cf0957c6b8faaaf7386a3bc69e53c0dc9705be
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c a43ba8a005fb5efd1deeee06853e3a6120d46a91
@@ -938,7 +938,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 5f15579f8ca747f0fa0a7867ceffc8c7b8f904e6
-R a63903941bea8f77658823b8763468e2
+P edb865c35415f9553f8279028120f7b8de2bf7e2
+R 3b765e3c18f9b2a8d8763c389176a0b5
 U drh
-Z 62e9bfe1cc7669e25feec8cecb39066d
+Z 3e70f15cebd9551500dd66c2327a7d64
diff --git a/manifest.uuid b/manifest.uuid
index 60ef9e438e..f3911243ba 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-edb865c35415f9553f8279028120f7b8de2bf7e2
\ No newline at end of file
+e3350dbd9f472c27ea6bc872d85098ac89d874c7
\ No newline at end of file
diff --git a/src/delete.c b/src/delete.c
index e5389e2b6a..a2df773af8 100644
--- a/src/delete.c
+++ b/src/delete.c
@@ -401,6 +401,7 @@ void sqlite3DeleteFrom(
       const char *pVTab = (const char *)sqlite3GetVTable(db, pTab);
       sqlite3VtabMakeWritable(pParse, pTab);
       sqlite3VdbeAddOp4(v, OP_VUpdate, 0, 1, iRowid, pVTab, P4_VTAB);
+      sqlite3VdbeChangeP5(v, OE_Abort);
       sqlite3MayAbort(pParse);
     }else
 #endif

From f4b595b929449c03383f8c20d1929f284c960cc9 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Mon, 30 May 2011 15:06:48 +0000
Subject: [PATCH 10/30] Update evidence marks on the URI filename tests to
 conform to the latest documentation.

FossilOrigin-Name: 1bab03c4811b5e5b3d15632bc2a3844891f9fad7
---
 manifest        | 12 ++++++------
 manifest.uuid   |  2 +-
 test/e_uri.test | 18 ++++++++++--------
 3 files changed, 17 insertions(+), 15 deletions(-)

diff --git a/manifest b/manifest
index f9e0a1ae94..207bb8d5bf 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Make\ssure\sthe\sP5\sargument\sto\sthe\sOP_VUpdate\sopcode\sis\salways\sset\sto\sa\nvalid\sconflict\sresolution\scode.
-D 2011-05-30T14:35:48.783
+C Update\sevidence\smarks\son\sthe\sURI\sfilename\stests\sto\sconform\sto\sthe\slatest\ndocumentation.
+D 2011-05-30T15:06:48.453
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -380,7 +380,7 @@ F test/e_resolve.test dcce9308fb13b934ce29591105d031d3e14fbba6
 F test/e_select.test bf385ae3aa0f014c4933ae66fd3e1302138493eb
 F test/e_select2.test 5c3d3da19c7b3e90ae444579db2b70098599ab92
 F test/e_update.test 963d6876064e65f318d1c93aaed36a02b9b389bf
-F test/e_uri.test 9ce11319fb9b271bf7392027f913f7830e93e7a7
+F test/e_uri.test b6da43a10f44d9aa0aff5ffa3c2f3de668361255
 F test/e_vacuum.test 6c09c2af7f2f140518f371c5342100118f779dcf
 F test/enc.test e54531cd6bf941ee6760be041dff19a104c7acea
 F test/enc2.test 6d91a5286f59add0cfcbb2d0da913b76f2242398
@@ -938,7 +938,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P edb865c35415f9553f8279028120f7b8de2bf7e2
-R 3b765e3c18f9b2a8d8763c389176a0b5
+P e3350dbd9f472c27ea6bc872d85098ac89d874c7
+R 31eb4302622f868d251135572f646bae
 U drh
-Z 3e70f15cebd9551500dd66c2327a7d64
+Z 47e43c01cd8d7b7136f7bc52a005ac53
diff --git a/manifest.uuid b/manifest.uuid
index f3911243ba..45419984ac 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-e3350dbd9f472c27ea6bc872d85098ac89d874c7
\ No newline at end of file
+1bab03c4811b5e5b3d15632bc2a3844891f9fad7
\ No newline at end of file
diff --git a/test/e_uri.test b/test/e_uri.test
index b0e2f876de..3e47427941 100644
--- a/test/e_uri.test
+++ b/test/e_uri.test
@@ -48,10 +48,11 @@ proc open_uri_error {uri} {
 # and the filename argument begins with "file:", then the filename is
 # interpreted as a URI.
 #
-# EVIDENCE-OF: R-00067-59538 URI filename interpretation is enabled if
+# EVIDENCE-OF: R-32637-34037 URI filename interpretation is enabled if
 # the SQLITE_OPEN_URI flag is is set in the fourth argument to
 # sqlite3_open_v2(), or if it has been enabled globally using the
-# SQLITE_CONFIG_URI option with the sqlite3_config() method.
+# SQLITE_CONFIG_URI option with the sqlite3_config() method or by the
+# SQLITE_USE_URI compile-time option.
 #
 if {$tcl_platform(platform) == "unix"} {
   set flags [list SQLITE_OPEN_READWRITE SQLITE_OPEN_CREATE]
@@ -140,8 +141,8 @@ if {$tcl_platform(platform) == "unix"} {
   }
 }
 
-# EVIDENCE-OF: R-43804-65312 The 'fragment' component of a URI, if
-# present, is always ignored.
+# EVIDENCE-OF: R-45981-25528 The fragment component of a URI, if
+# present, is ignored.
 #
 #   It is difficult to test that something is ignore correctly. So these tests
 #   just show that adding a fragment does not interfere with the pathname or
@@ -157,14 +158,15 @@ if {$tcl_platform(platform) == "unix"} {
   }
 }
 
-# EVIDENCE-OF: R-00273-20588 SQLite uses the 'path' component of the URI
-# as the path to the database file to open.
+# EVIDENCE-OF: R-62557-09390 SQLite uses the path component of the URI
+# as the name of the disk file which contains the database.
 #
 # EVIDENCE-OF: R-28659-11035 If the path begins with a '/' character,
 # then it is interpreted as an absolute path.
 #
-# EVIDENCE-OF: R-39349-47203 If it does not begin with a '/', it is
-# interpreted as a relative path.
+# EVIDENCE-OF: R-46234-61323 If the path does not begin with a '/'
+# (meaning that the authority section is omitted from the URI) then the
+# path is interpreted as a relative path.
 #
 if {$tcl_platform(platform) == "unix"} {
   foreach {tn uri parse} "

From c3f1d5f0958df10afadc10cd24ea1fb1d7003dfb Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Mon, 30 May 2011 23:42:16 +0000
Subject: [PATCH 11/30] Minor performance improvements.

FossilOrigin-Name: f9950c6af1813f724dacd7455f472acec921b06a
---
 manifest      | 16 ++++++++--------
 manifest.uuid |  2 +-
 src/btree.c   |  6 ++++--
 src/vdbe.c    | 28 ++++++++++++++--------------
 src/vdbeaux.c |  4 +++-
 5 files changed, 30 insertions(+), 26 deletions(-)

diff --git a/manifest b/manifest
index 207bb8d5bf..b9205ae2bb 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Update\sevidence\smarks\son\sthe\sURI\sfilename\stests\sto\sconform\sto\sthe\slatest\ndocumentation.
-D 2011-05-30T15:06:48.453
+C Minor\sperformance\simprovements.
+D 2011-05-30T23:42:16.233
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -122,7 +122,7 @@ F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
 F src/backup.c 986c15232757f2873dff35ee3b35cbf935fc573c
 F src/bitvec.c af50f1c8c0ff54d6bdb7a80e2fceca5a93670bef
 F src/btmutex.c 976f45a12e37293e32cae0281b15a21d48a8aaa7
-F src/btree.c 975ad691a57eb1fb60f1ec76ad0b6571eace62f9
+F src/btree.c 0d3b39dcb79565c053e35fc12713f12d8a74d6a9
 F src/btree.h f5d775cd6cfc7ac32a2535b70e8d2af48ef5f2ce
 F src/btreeInt.h 67978c014fa4f7cc874032dd3aacadd8db656bc3
 F src/build.c 0132bc6631fa617a1d28ef805921f6dbac18a514
@@ -236,11 +236,11 @@ F src/update.c 5bcb56e5c7380a2eecb0e71891dbd4ad7437748f
 F src/utf.c d83650c3ea08f7407bd9d0839d9885241c209c60
 F src/util.c 0f33bbbdfcc4a2d8cf20c3b2a16ffc3b57c58a70
 F src/vacuum.c 05513dca036a1e7848fe18d5ed1265ac0b32365e
-F src/vdbe.c 380dddc404c1e4a9260a4194daa728b94ed102d7
+F src/vdbe.c 103827f560cdc48b1d455ce4d4b3573dd88f9ab4
 F src/vdbe.h 8a675fefdf7119441fe817c800a9a52440c2e797
 F src/vdbeInt.h fe8f58d305e629fff02f61f655aca1d299f1f6ae
 F src/vdbeapi.c e0e2672e0a96ae3f8575c8ecd02912a3e8a554a1
-F src/vdbeaux.c 07a5226ae6e9c6e54b5fcd3c395b86e7ffdba3a4
+F src/vdbeaux.c 99900868d18618a07ffaf780ecc41fd807834bde
 F src/vdbeblob.c c3ccb7c8732858c680f442932e66ad06bb036562
 F src/vdbemem.c 0498796b6ffbe45e32960d6a1f5adfb6e419883b
 F src/vdbetrace.c 5d0dc3d5fd54878cc8d6d28eb41deb8d5885b114
@@ -938,7 +938,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P e3350dbd9f472c27ea6bc872d85098ac89d874c7
-R 31eb4302622f868d251135572f646bae
+P 1bab03c4811b5e5b3d15632bc2a3844891f9fad7
+R 7acb04adb38e3c88e3b1f83ed6f40a4e
 U drh
-Z 47e43c01cd8d7b7136f7bc52a005ac53
+Z 9e474b54141fcb6c3097a32384090f3c
diff --git a/manifest.uuid b/manifest.uuid
index 45419984ac..58a05fb539 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-1bab03c4811b5e5b3d15632bc2a3844891f9fad7
\ No newline at end of file
+f9950c6af1813f724dacd7455f472acec921b06a
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index df75053743..972a2f608c 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -5390,10 +5390,10 @@ static int fillInCell(
 ** "sz" must be the number of bytes in the cell.
 */
 static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
-  int i;          /* Loop counter */
   u32 pc;         /* Offset to cell content of cell being deleted */
   u8 *data;       /* pPage->aData */
   u8 *ptr;        /* Used to move bytes around within data[] */
+  u8 *endPtr;     /* End of loop */
   int rc;         /* The return code */
   int hdr;        /* Beginning of the header.  0 most pages.  100 page 1 */
 
@@ -5418,9 +5418,11 @@ static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
     *pRC = rc;
     return;
   }
-  for(i=idx+1; i<pPage->nCell; i++, ptr+=2){
+  endPtr = &data[pPage->cellOffset + 2*pPage->nCell - 2];
+  while( ptr<endPtr ){
     ptr[0] = ptr[2];
     ptr[1] = ptr[3];
+    ptr += 2;
   }
   pPage->nCell--;
   put2byte(&data[hdr+3], pPage->nCell);
diff --git a/src/vdbe.c b/src/vdbe.c
index d28f73d1b1..eea6aba70e 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -1766,7 +1766,7 @@ case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
   pIn3 = &aMem[pOp->p3];
   flags1 = pIn1->flags;
   flags3 = pIn3->flags;
-  if( (pIn1->flags | pIn3->flags)&MEM_Null ){
+  if( (flags1 | flags3)&MEM_Null ){
     /* One or both operands are NULL */
     if( pOp->p5 & SQLITE_NULLEQ ){
       /* If SQLITE_NULLEQ is set (which will only happen if the operator is
@@ -1774,7 +1774,7 @@ case OP_Ge: {             /* same as TK_GE, jump, in1, in3 */
       ** or not both operands are null.
       */
       assert( pOp->opcode==OP_Eq || pOp->opcode==OP_Ne );
-      res = (pIn1->flags & pIn3->flags & MEM_Null)==0;
+      res = (flags1 & flags3 & MEM_Null)==0;
     }else{
       /* SQLITE_NULLEQ is clear and at least one operand is NULL,
       ** then the result is always NULL.
@@ -5882,20 +5882,20 @@ case OP_MaxPgcnt: {            /* out2-prerelease */
 */
 case OP_Trace: {
   char *zTrace;
+  char *z;
 
-  zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql);
-  if( zTrace ){
-    if( db->xTrace ){
-      char *z = sqlite3VdbeExpandSql(p, zTrace);
-      db->xTrace(db->pTraceArg, z);
-      sqlite3DbFree(db, z);
-    }
-#ifdef SQLITE_DEBUG
-    if( (db->flags & SQLITE_SqlTrace)!=0 ){
-      sqlite3DebugPrintf("SQL-trace: %s\n", zTrace);
-    }
-#endif /* SQLITE_DEBUG */
+  if( db->xTrace && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0 ){
+    z = sqlite3VdbeExpandSql(p, zTrace);
+    db->xTrace(db->pTraceArg, z);
+    sqlite3DbFree(db, z);
   }
+#ifdef SQLITE_DEBUG
+  if( (db->flags & SQLITE_SqlTrace)!=0
+   && (zTrace = (pOp->p4.z ? pOp->p4.z : p->zSql))!=0
+  ){
+    sqlite3DebugPrintf("SQL-trace: %s\n", zTrace);
+  }
+#endif /* SQLITE_DEBUG */
   break;
 }
 #endif
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index e9764a5096..0322b04c21 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -2852,7 +2852,7 @@ UnpackedRecord *sqlite3VdbeRecordUnpack(
     idx += getVarint32(&aKey[idx], serial_type);
     pMem->enc = pKeyInfo->enc;
     pMem->db = pKeyInfo->db;
-    pMem->flags = 0;
+    /* pMem->flags = 0; // sqlite3VdbeSerialGet() will set this for us */
     pMem->zMalloc = 0;
     d += sqlite3VdbeSerialGet(&aKey[d], serial_type, pMem);
     pMem++;
@@ -2867,6 +2867,7 @@ UnpackedRecord *sqlite3VdbeRecordUnpack(
 ** This routine destroys a UnpackedRecord object.
 */
 void sqlite3VdbeDeleteUnpackedRecord(UnpackedRecord *p){
+#ifdef SQLITE_DEBUG
   int i;
   Mem *pMem;
 
@@ -2880,6 +2881,7 @@ void sqlite3VdbeDeleteUnpackedRecord(UnpackedRecord *p){
     */
     if( NEVER(pMem->zMalloc) ) sqlite3VdbeMemRelease(pMem);
   }
+#endif
   if( p->flags & UNPACKED_NEED_FREE ){
     sqlite3DbFree(p->pKeyInfo->db, p);
   }

From a80a141247a233e71d0adc29244096eebf3204f0 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Tue, 31 May 2011 11:56:15 +0000
Subject: [PATCH 12/30] Update the documentation to state that any parameter
 that is optimized out of a prepared statement becomes an anonymous parameter
 for which sqlite3_bind_parameter_name() returns NULL.

FossilOrigin-Name: 701b8a23e3ea2c94454af5d9bd1e72acb66d0fe2
---
 manifest        | 12 ++++++------
 manifest.uuid   |  2 +-
 src/sqlite.h.in |  2 ++
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/manifest b/manifest
index b9205ae2bb..f7cee8fa4c 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Minor\sperformance\simprovements.
-D 2011-05-30T23:42:16.233
+C Update\sthe\sdocumentation\sto\sstate\sthat\sany\sparameter\sthat\sis\soptimized\sout\nof\sa\sprepared\sstatement\sbecomes\san\sanonymous\sparameter\sfor\swhich\nsqlite3_bind_parameter_name()\sreturns\sNULL.
+D 2011-05-31T11:56:15.040
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -179,7 +179,7 @@ F src/resolve.c 1c0f32b64f8e3f555fe1f732f9d6f501a7f05706
 F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
 F src/select.c d9d440809025a58547e39f4f268c2a296bfb56ff
 F src/shell.c decd04236a7ef26be5ef46d4ea963044bfad9a48
-F src/sqlite.h.in 91c63a69eeddbd62182ec00dbfee390016972bdb
+F src/sqlite.h.in c095996e68e0082f674f32e68ca909fc24196a2a
 F src/sqlite3ext.h c90bd5507099f62043832d73f6425d8d5c5da754
 F src/sqliteInt.h d9ff5f198b5bac7ee0c6e1ea55f76897ba4dda87
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
@@ -938,7 +938,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 1bab03c4811b5e5b3d15632bc2a3844891f9fad7
-R 7acb04adb38e3c88e3b1f83ed6f40a4e
+P f9950c6af1813f724dacd7455f472acec921b06a
+R f6b845f51167252cf7d20999b01d5085
 U drh
-Z 9e474b54141fcb6c3097a32384090f3c
+Z 659dc0a03ae6f4d76444e7107181eaaf
diff --git a/manifest.uuid b/manifest.uuid
index 58a05fb539..6374f63920 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-f9950c6af1813f724dacd7455f472acec921b06a
\ No newline at end of file
+701b8a23e3ea2c94454af5d9bd1e72acb66d0fe2
\ No newline at end of file
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index 445a247a19..a9d60e8a2d 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -3068,6 +3068,8 @@ int sqlite3_bind_parameter_count(sqlite3_stmt*);
 ** is included as part of the name.)^
 ** ^Parameters of the form "?" without a following integer have no name
 ** and are referred to as "nameless" or "anonymous parameters".
+** ^Any parameter that is optimized out of the prepared statement by the 
+** query planner becomes a nameless or anonymous parameter.
 **
 ** ^The first host parameter has an index of 1, not 0.
 **

From ed9624187d89a96e591353a7bdee53b292e6f849 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Tue, 31 May 2011 16:50:23 +0000
Subject: [PATCH 13/30] Fix a problem in the sqlite3TestErrorName() function
 (used only for testing) that appears to have originated from a bad merge.

FossilOrigin-Name: a0ae314c7f41d0146a9ee1adc576cd977219a378
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/test1.c   |  1 -
 3 files changed, 7 insertions(+), 8 deletions(-)

diff --git a/manifest b/manifest
index f7cee8fa4c..9323cd6b55 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Update\sthe\sdocumentation\sto\sstate\sthat\sany\sparameter\sthat\sis\soptimized\sout\nof\sa\sprepared\sstatement\sbecomes\san\sanonymous\sparameter\sfor\swhich\nsqlite3_bind_parameter_name()\sreturns\sNULL.
-D 2011-05-31T11:56:15.040
+C Fix\sa\sproblem\sin\sthe\ssqlite3TestErrorName()\sfunction\s(used\sonly\sfor\stesting)\nthat\sappears\sto\shave\soriginated\sfrom\sa\sbad\smerge.
+D 2011-05-31T16:50:23.129
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -186,7 +186,7 @@ F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac64842c86cec2fc1a1d0e5c16d3beb8ad332bf
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
 F src/tclsqlite.c 501c9a200fd998a268be475be5858febc90b725b
-F src/test1.c 4a1171af201be90c21d64a872e686b1333d9a2cf
+F src/test1.c 9f61b9d23938bc5dd165ec7b95a91c30ce6e66db
 F src/test2.c 80d323d11e909cf0eb1b6fbb4ac22276483bcf31
 F src/test3.c 124ff9735fb6bb7d41de180d6bac90e7b1509432
 F src/test4.c d1e5a5e904d4b444cf572391fdcb017638e36ff7
@@ -938,7 +938,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P f9950c6af1813f724dacd7455f472acec921b06a
-R f6b845f51167252cf7d20999b01d5085
+P 701b8a23e3ea2c94454af5d9bd1e72acb66d0fe2
+R 0252c62ef68072dedfcd687577c244b5
 U drh
-Z 659dc0a03ae6f4d76444e7107181eaaf
+Z 32d78009c9e58634b2f842adf352a1be
diff --git a/manifest.uuid b/manifest.uuid
index 6374f63920..55d88bed1a 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-701b8a23e3ea2c94454af5d9bd1e72acb66d0fe2
\ No newline at end of file
+a0ae314c7f41d0146a9ee1adc576cd977219a378
\ No newline at end of file
diff --git a/src/test1.c b/src/test1.c
index 50575afbbc..7d31c6d02a 100644
--- a/src/test1.c
+++ b/src/test1.c
@@ -164,7 +164,6 @@ const char *sqlite3TestErrorName(int rc){
                                zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
     case SQLITE_IOERR_LOCK:          zName = "SQLITE_IOERR_LOCK";        break;
     case SQLITE_CORRUPT_VTAB:        zName = "SQLITE_CORRUPT_VTAB";      break;
-                               zName = "SQLITE_IOERR_CHECKRESERVEDLOCK"; break;
     default:                         zName = "SQLITE_Unknown";           break;
   }
   return zName;

From 124c0b49a19ce24302c6594e60c80c7ba4df6c98 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Wed, 1 Jun 2011 18:15:55 +0000
Subject: [PATCH 14/30] Refactor the SQL parameter processing so that parameter
 names for values that are optimized out of the prepare statement are not
 forgotten.

FossilOrigin-Name: b3aaf715b60b8a338cc6c92dad1ead4a3f7146a3
---
 manifest        |  30 +++----
 manifest.uuid   |   2 +-
 src/build.c     |   4 +-
 src/expr.c      |  86 +++++++++---------
 src/sqlite.h.in |   2 -
 src/sqliteInt.h |   5 +-
 src/tokenize.c  |   8 +-
 src/vdbe.h      |   3 +-
 src/vdbeInt.h   |   2 +-
 src/vdbeapi.c   |  34 +------
 src/vdbeaux.c   | 229 ++++++++++++++++++++++++++----------------------
 src/vdbeblob.c  |   5 +-
 12 files changed, 202 insertions(+), 208 deletions(-)

diff --git a/manifest b/manifest
index 9323cd6b55..b747a1409f 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sa\sproblem\sin\sthe\ssqlite3TestErrorName()\sfunction\s(used\sonly\sfor\stesting)\nthat\sappears\sto\shave\soriginated\sfrom\sa\sbad\smerge.
-D 2011-05-31T16:50:23.129
+C Refactor\sthe\sSQL\sparameter\sprocessing\sso\sthat\sparameter\snames\sfor\svalues\nthat\sare\soptimized\sout\sof\sthe\sprepare\sstatement\sare\snot\sforgotten.
+D 2011-06-01T18:15:55.858
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -125,13 +125,13 @@ F src/btmutex.c 976f45a12e37293e32cae0281b15a21d48a8aaa7
 F src/btree.c 0d3b39dcb79565c053e35fc12713f12d8a74d6a9
 F src/btree.h f5d775cd6cfc7ac32a2535b70e8d2af48ef5f2ce
 F src/btreeInt.h 67978c014fa4f7cc874032dd3aacadd8db656bc3
-F src/build.c 0132bc6631fa617a1d28ef805921f6dbac18a514
+F src/build.c c10ab9e2c77ade99dee23554787f8acfc0c231fc
 F src/callback.c 0425c6320730e6d3981acfb9202c1bed9016ad1a
 F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c 7deec4534f3b5a0c3b4a4cbadf809d321f64f9c4
 F src/date.c 1548fdac51377e4e7833251de878b4058c148e1b
 F src/delete.c cecc926c70783452f3e8eb452c728291ce1a0b21
-F src/expr.c e3cf0957c6b8faaaf7386a3bc69e53c0dc9705be
+F src/expr.c c33584bcf4ee011e28ff74e4dcef02da1dc09dd6
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c a43ba8a005fb5efd1deeee06853e3a6120d46a91
 F src/func.c b9117e40975245b8504cf3625d7e321d8d4b63dc
@@ -179,9 +179,9 @@ F src/resolve.c 1c0f32b64f8e3f555fe1f732f9d6f501a7f05706
 F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
 F src/select.c d9d440809025a58547e39f4f268c2a296bfb56ff
 F src/shell.c decd04236a7ef26be5ef46d4ea963044bfad9a48
-F src/sqlite.h.in c095996e68e0082f674f32e68ca909fc24196a2a
+F src/sqlite.h.in 91c63a69eeddbd62182ec00dbfee390016972bdb
 F src/sqlite3ext.h c90bd5507099f62043832d73f6425d8d5c5da754
-F src/sqliteInt.h d9ff5f198b5bac7ee0c6e1ea55f76897ba4dda87
+F src/sqliteInt.h 6e58c558c57c8f44011736d5fa5295eb3130f9de
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac64842c86cec2fc1a1d0e5c16d3beb8ad332bf
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -230,18 +230,18 @@ F src/test_vfs.c e7855568dfa1e0ba73668d273b65605d9f8b77e8
 F src/test_vfstrace.c 0b884e06094a746da729119a2cabdc7aa790063d
 F src/test_wholenumber.c 6129adfbe7c7444f2e60cc785927f3aa74e12290
 F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
-F src/tokenize.c 604607d6813e9551cf5189d899e0a25c12681080
+F src/tokenize.c 7b0c9281b2368dc69135e7a50bd271de9af1b467
 F src/trigger.c 144cc18bb701f3286484aae4292a9531f09278c8
 F src/update.c 5bcb56e5c7380a2eecb0e71891dbd4ad7437748f
 F src/utf.c d83650c3ea08f7407bd9d0839d9885241c209c60
 F src/util.c 0f33bbbdfcc4a2d8cf20c3b2a16ffc3b57c58a70
 F src/vacuum.c 05513dca036a1e7848fe18d5ed1265ac0b32365e
 F src/vdbe.c 103827f560cdc48b1d455ce4d4b3573dd88f9ab4
-F src/vdbe.h 8a675fefdf7119441fe817c800a9a52440c2e797
-F src/vdbeInt.h fe8f58d305e629fff02f61f655aca1d299f1f6ae
-F src/vdbeapi.c e0e2672e0a96ae3f8575c8ecd02912a3e8a554a1
-F src/vdbeaux.c 99900868d18618a07ffaf780ecc41fd807834bde
-F src/vdbeblob.c c3ccb7c8732858c680f442932e66ad06bb036562
+F src/vdbe.h d9c6123384189dc37d27beac1bf44688aa75b6cb
+F src/vdbeInt.h ad84226cc0adcb1185c22b70696b235a1678bb45
+F src/vdbeapi.c 0eeadc75e44a30efd996d6af6e7c5a2488e35be8
+F src/vdbeaux.c 0505dc4f7ff3cf35e219fe0a20ab798a42772b8b
+F src/vdbeblob.c f024f0bf420f36b070143c32b15cc7287341ffd3
 F src/vdbemem.c 0498796b6ffbe45e32960d6a1f5adfb6e419883b
 F src/vdbetrace.c 5d0dc3d5fd54878cc8d6d28eb41deb8d5885b114
 F src/vtab.c 9ba8c7fdb7d39260c033a402f6032d3e7bc5d336
@@ -938,7 +938,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 701b8a23e3ea2c94454af5d9bd1e72acb66d0fe2
-R 0252c62ef68072dedfcd687577c244b5
+P a0ae314c7f41d0146a9ee1adc576cd977219a378
+R d99e1065a540709b7ea760de89dbcfd0
 U drh
-Z 32d78009c9e58634b2f842adf352a1be
+Z ce5ce2791f47aa05a4daaafded206f56
diff --git a/manifest.uuid b/manifest.uuid
index 55d88bed1a..4597483a7e 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-a0ae314c7f41d0146a9ee1adc576cd977219a378
\ No newline at end of file
+b3aaf715b60b8a338cc6c92dad1ead4a3f7146a3
\ No newline at end of file
diff --git a/src/build.c b/src/build.c
index fa2d53a14b..afe2089325 100644
--- a/src/build.c
+++ b/src/build.c
@@ -200,9 +200,7 @@ void sqlite3FinishCoding(Parse *pParse){
     /* A minimum of one cursor is required if autoincrement is used
     *  See ticket [a696379c1f08866] */
     if( pParse->pAinc!=0 && pParse->nTab==0 ) pParse->nTab = 1;
-    sqlite3VdbeMakeReady(v, pParse->nVar, pParse->nMem,
-                         pParse->nTab, pParse->nMaxArg, pParse->explain,
-                         pParse->isMultiWrite && pParse->mayAbort);
+    sqlite3VdbeMakeReady(v, pParse);
     pParse->rc = SQLITE_DONE;
     pParse->colNamesSet = 0;
   }else{
diff --git a/src/expr.c b/src/expr.c
index c0e9ba6fd5..4cd2f24551 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -555,53 +555,53 @@ void sqlite3ExprAssignVarNumber(Parse *pParse, Expr *pExpr){
     /* Wildcard of the form "?".  Assign the next variable number */
     assert( z[0]=='?' );
     pExpr->iColumn = (ynVar)(++pParse->nVar);
-  }else if( z[0]=='?' ){
-    /* Wildcard of the form "?nnn".  Convert "nnn" to an integer and
-    ** use it as the variable number */
-    i64 i;
-    int bOk = 0==sqlite3Atoi64(&z[1], &i, sqlite3Strlen30(&z[1]), SQLITE_UTF8);
-    pExpr->iColumn = (ynVar)i;
-    testcase( i==0 );
-    testcase( i==1 );
-    testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
-    testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
-    if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
-      sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
-          db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
-    }
-    if( i>pParse->nVar ){
-      pParse->nVar = (int)i;
-    }
   }else{
-    /* Wildcards like ":aaa", "$aaa" or "@aaa".  Reuse the same variable
-    ** number as the prior appearance of the same name, or if the name
-    ** has never appeared before, reuse the same variable number
-    */
-    int i;
-    u32 n;
-    n = sqlite3Strlen30(z);
-    for(i=0; i<pParse->nVarExpr; i++){
-      Expr *pE = pParse->apVarExpr[i];
-      assert( pE!=0 );
-      if( memcmp(pE->u.zToken, z, n)==0 && pE->u.zToken[n]==0 ){
-        pExpr->iColumn = pE->iColumn;
-        break;
+    ynVar x = 0;
+    u32 n = sqlite3Strlen30(z);
+    if( z[0]=='?' ){
+      /* Wildcard of the form "?nnn".  Convert "nnn" to an integer and
+      ** use it as the variable number */
+      i64 i;
+      int bOk = 0==sqlite3Atoi64(&z[1], &i, n-1, SQLITE_UTF8);
+      pExpr->iColumn = x = (ynVar)i;
+      testcase( i==0 );
+      testcase( i==1 );
+      testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]-1 );
+      testcase( i==db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] );
+      if( bOk==0 || i<1 || i>db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER] ){
+        sqlite3ErrorMsg(pParse, "variable number must be between ?1 and ?%d",
+            db->aLimit[SQLITE_LIMIT_VARIABLE_NUMBER]);
+        x = 0;
       }
+      if( i>pParse->nVar ){
+        pParse->nVar = (int)i;
+      }
+    }else{
+      /* Wildcards like ":aaa", "$aaa" or "@aaa".  Reuse the same variable
+      ** number as the prior appearance of the same name, or if the name
+      ** has never appeared before, reuse the same variable number
+      */
+      ynVar i;
+      for(i=0; i<pParse->nzVar; i++){
+        if( pParse->azVar[i] && memcmp(pParse->azVar[i],z,n+1)==0 ){
+          pExpr->iColumn = x = (ynVar)i+1;
+          break;
+        }
+      }
+      if( x==0 ) x = pExpr->iColumn = (ynVar)(++pParse->nVar);
     }
-    if( i>=pParse->nVarExpr ){
-      pExpr->iColumn = (ynVar)(++pParse->nVar);
-      if( pParse->nVarExpr>=pParse->nVarExprAlloc-1 ){
-        pParse->nVarExprAlloc += pParse->nVarExprAlloc + 10;
-        pParse->apVarExpr =
-            sqlite3DbReallocOrFree(
-              db,
-              pParse->apVarExpr,
-              pParse->nVarExprAlloc*sizeof(pParse->apVarExpr[0])
-            );
+    if( x>0 ){
+      if( x>pParse->nzVar ){
+        char **a;
+        a = sqlite3DbRealloc(db, pParse->azVar, x*sizeof(a[0]));
+        if( a==0 ) return;  /* Error reported through db->mallocFailed */
+        pParse->azVar = a;
+        memset(&a[pParse->nzVar], 0, (x-pParse->nzVar)*sizeof(a[0]));
+        pParse->nzVar = x;
       }
-      if( !db->mallocFailed ){
-        assert( pParse->apVarExpr!=0 );
-        pParse->apVarExpr[pParse->nVarExpr++] = pExpr;
+      if( z[0]!='?' || pParse->azVar[x-1]==0 ){
+        sqlite3DbFree(db, pParse->azVar[x-1]);
+        pParse->azVar[x-1] = sqlite3DbStrNDup(db, z, n);
       }
     }
   } 
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index a9d60e8a2d..445a247a19 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -3068,8 +3068,6 @@ int sqlite3_bind_parameter_count(sqlite3_stmt*);
 ** is included as part of the name.)^
 ** ^Parameters of the form "?" without a following integer have no name
 ** and are referred to as "nameless" or "anonymous parameters".
-** ^Any parameter that is optimized out of the prepared statement by the 
-** query planner becomes a nameless or anonymous parameter.
 **
 ** ^The first host parameter has an index of 1, not 0.
 **
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index bba0b3c441..fd86158e00 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2230,9 +2230,8 @@ struct Parse {
   ** each recursion */
 
   int nVar;            /* Number of '?' variables seen in the SQL so far */
-  int nVarExpr;        /* Number of used slots in apVarExpr[] */
-  int nVarExprAlloc;   /* Number of allocated slots in apVarExpr[] */
-  Expr **apVarExpr;    /* Pointers to :aaa and $aaaa wildcard expressions */
+  int nzVar;           /* Number of available slots in azVar[] */
+  char **azVar;        /* Pointers to names of parameters */
   Vdbe *pReprepare;    /* VM being reprepared (sqlite3Reprepare()) */
   int nAlias;          /* Number of aliased result set columns */
   int nAliasAlloc;     /* Number of allocated slots for aAlias[] */
diff --git a/src/tokenize.c b/src/tokenize.c
index c624efdcc7..016a218262 100644
--- a/src/tokenize.c
+++ b/src/tokenize.c
@@ -412,9 +412,8 @@ int sqlite3RunParser(Parse *pParse, const char *zSql, char **pzErrMsg){
   assert( pParse->pNewTable==0 );
   assert( pParse->pNewTrigger==0 );
   assert( pParse->nVar==0 );
-  assert( pParse->nVarExpr==0 );
-  assert( pParse->nVarExprAlloc==0 );
-  assert( pParse->apVarExpr==0 );
+  assert( pParse->nzVar==0 );
+  assert( pParse->azVar==0 );
   enableLookaside = db->lookaside.bEnabled;
   if( db->lookaside.pStart ) db->lookaside.bEnabled = 1;
   while( !db->mallocFailed && zSql[i]!=0 ){
@@ -508,7 +507,8 @@ abort_parse:
   }
 
   sqlite3DeleteTrigger(db, pParse->pNewTrigger);
-  sqlite3DbFree(db, pParse->apVarExpr);
+  for(i=pParse->nzVar-1; i>=0; i--) sqlite3DbFree(db, pParse->azVar[i]);
+  sqlite3DbFree(db, pParse->azVar);
   sqlite3DbFree(db, pParse->aAlias);
   while( pParse->pAinc ){
     AutoincInfo *p = pParse->pAinc;
diff --git a/src/vdbe.h b/src/vdbe.h
index 43044533f3..56f9eb51ca 100644
--- a/src/vdbe.h
+++ b/src/vdbe.h
@@ -185,7 +185,7 @@ int sqlite3VdbeMakeLabel(Vdbe*);
 void sqlite3VdbeRunOnlyOnce(Vdbe*);
 void sqlite3VdbeDelete(Vdbe*);
 void sqlite3VdbeDeleteObject(sqlite3*,Vdbe*);
-void sqlite3VdbeMakeReady(Vdbe*,int,int,int,int,int,int);
+void sqlite3VdbeMakeReady(Vdbe*,Parse*);
 int sqlite3VdbeFinalize(Vdbe*);
 void sqlite3VdbeResolveLabel(Vdbe*, int);
 int sqlite3VdbeCurrentAddr(Vdbe*);
@@ -194,6 +194,7 @@ int sqlite3VdbeCurrentAddr(Vdbe*);
   void sqlite3VdbeTrace(Vdbe*,FILE*);
 #endif
 void sqlite3VdbeResetStepResult(Vdbe*);
+void sqlite3VdbeRewind(Vdbe*);
 int sqlite3VdbeReset(Vdbe*);
 void sqlite3VdbeSetNumCols(Vdbe*,int);
 int sqlite3VdbeSetColName(Vdbe*, int, int, const char *, void(*)(void*));
diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index 5e96c6f9ff..0aeb3af7a9 100644
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -287,11 +287,11 @@ struct Vdbe {
   Mem *aVar;              /* Values for the OP_Variable opcode. */
   char **azVar;           /* Name of variables */
   ynVar nVar;             /* Number of entries in aVar[] */
+  ynVar nzVar;            /* Number of entries in azVar[] */
   u32 cacheCtr;           /* VdbeCursor row cache generation counter */
   int pc;                 /* The program counter */
   int rc;                 /* Value to return */
   u8 errorAction;         /* Recovery action to do in case of an error */
-  u8 okVar;               /* True if azVar[] has been initialized */
   u8 explain;             /* True if EXPLAIN present on SQL command */
   u8 changeCntOn;         /* True to update the change-counter */
   u8 expired;             /* True if the VM needs to be recompiled */
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index 90baaccc68..5923a4c01f 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -102,7 +102,7 @@ int sqlite3_reset(sqlite3_stmt *pStmt){
     Vdbe *v = (Vdbe*)pStmt;
     sqlite3_mutex_enter(v->db->mutex);
     rc = sqlite3VdbeReset(v);
-    sqlite3VdbeMakeReady(v, -1, 0, 0, 0, 0, 0);
+    sqlite3VdbeRewind(v);
     assert( (rc & (v->db->errMask))==rc );
     rc = sqlite3ApiExit(v->db, rc);
     sqlite3_mutex_leave(v->db->mutex);
@@ -1167,32 +1167,6 @@ int sqlite3_bind_parameter_count(sqlite3_stmt *pStmt){
   return p ? p->nVar : 0;
 }
 
-/*
-** Create a mapping from variable numbers to variable names
-** in the Vdbe.azVar[] array, if such a mapping does not already
-** exist.
-*/
-static void createVarMap(Vdbe *p){
-  if( !p->okVar ){
-    int j;
-    Op *pOp;
-    sqlite3_mutex_enter(p->db->mutex);
-    /* The race condition here is harmless.  If two threads call this
-    ** routine on the same Vdbe at the same time, they both might end
-    ** up initializing the Vdbe.azVar[] array.  That is a little extra
-    ** work but it results in the same answer.
-    */
-    for(j=0, pOp=p->aOp; j<p->nOp; j++, pOp++){
-      if( pOp->opcode==OP_Variable ){
-        assert( pOp->p1>0 && pOp->p1<=p->nVar );
-        p->azVar[pOp->p1-1] = pOp->p4.z;
-      }
-    }
-    p->okVar = 1;
-    sqlite3_mutex_leave(p->db->mutex);
-  }
-}
-
 /*
 ** Return the name of a wildcard parameter.  Return NULL if the index
 ** is out of range or if the wildcard is unnamed.
@@ -1201,10 +1175,9 @@ static void createVarMap(Vdbe *p){
 */
 const char *sqlite3_bind_parameter_name(sqlite3_stmt *pStmt, int i){
   Vdbe *p = (Vdbe*)pStmt;
-  if( p==0 || i<1 || i>p->nVar ){
+  if( p==0 || i<1 || i>p->nzVar ){
     return 0;
   }
-  createVarMap(p);
   return p->azVar[i-1];
 }
 
@@ -1218,9 +1191,8 @@ int sqlite3VdbeParameterIndex(Vdbe *p, const char *zName, int nName){
   if( p==0 ){
     return 0;
   }
-  createVarMap(p); 
   if( zName ){
-    for(i=0; i<p->nVar; i++){
+    for(i=0; i<p->nzVar; i++){
       const char *z = p->azVar[i];
       if( z && memcmp(z,zName,nName)==0 && z[nName]==0 ){
         return i+1;
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index 0322b04c21..8181f01aa3 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -1391,34 +1391,13 @@ static void *allocSpace(
 }
 
 /*
-** Prepare a virtual machine for execution.  This involves things such
-** as allocating stack space and initializing the program counter.
-** After the VDBE has be prepped, it can be executed by one or more
-** calls to sqlite3VdbeExec().  
-**
-** This is the only way to move a VDBE from VDBE_MAGIC_INIT to
-** VDBE_MAGIC_RUN.
-**
-** This function may be called more than once on a single virtual machine.
-** The first call is made while compiling the SQL statement. Subsequent
-** calls are made as part of the process of resetting a statement to be
-** re-executed (from a call to sqlite3_reset()). The nVar, nMem, nCursor 
-** and isExplain parameters are only passed correct values the first time
-** the function is called. On subsequent calls, from sqlite3_reset(), nVar
-** is passed -1 and nMem, nCursor and isExplain are all passed zero.
+** Rewind the VDBE back to the beginning in preparation for
+** running it.
 */
-void sqlite3VdbeMakeReady(
-  Vdbe *p,                       /* The VDBE */
-  int nVar,                      /* Number of '?' see in the SQL statement */
-  int nMem,                      /* Number of memory cells to allocate */
-  int nCursor,                   /* Number of cursors to allocate */
-  int nArg,                      /* Maximum number of args in SubPrograms */
-  int isExplain,                 /* True if the EXPLAIN keywords is present */
-  int usesStmtJournal            /* True to set Vdbe.usesStmtJournal */
-){
-  int n;
-  sqlite3 *db = p->db;
-
+void sqlite3VdbeRewind(Vdbe *p){
+#if defined(SQLITE_DEBUG) || defined(VDBE_PROFILE)
+  int i;
+#endif
   assert( p!=0 );
   assert( p->magic==VDBE_MAGIC_INIT );
 
@@ -1429,6 +1408,71 @@ void sqlite3VdbeMakeReady(
   /* Set the magic to VDBE_MAGIC_RUN sooner rather than later. */
   p->magic = VDBE_MAGIC_RUN;
 
+#ifdef SQLITE_DEBUG
+  for(i=1; i<p->nMem; i++){
+    assert( p->aMem[i].db==p->db );
+  }
+#endif
+  p->pc = -1;
+  p->rc = SQLITE_OK;
+  p->errorAction = OE_Abort;
+  p->magic = VDBE_MAGIC_RUN;
+  p->nChange = 0;
+  p->cacheCtr = 1;
+  p->minWriteFileFormat = 255;
+  p->iStatement = 0;
+  p->nFkConstraint = 0;
+#ifdef VDBE_PROFILE
+  for(i=0; i<p->nOp; i++){
+    p->aOp[i].cnt = 0;
+    p->aOp[i].cycles = 0;
+  }
+#endif
+}
+
+/*
+** Prepare a virtual machine for execution for the first time after
+** creating the virtual machine.  This involves things such
+** as allocating stack space and initializing the program counter.
+** After the VDBE has be prepped, it can be executed by one or more
+** calls to sqlite3VdbeExec().  
+**
+** This function may be called exact once on a each virtual machine.
+** After this routine is called the VM has been "packaged" and is ready
+** to run.  After this routine is called, futher calls to 
+** sqlite3VdbeAddOp() functions are prohibited.  This routine disconnects
+** the Vdbe from the Parse object that helped generate it so that the
+** the Vdbe becomes an independent entity and the Parse object can be
+** destroyed.
+**
+** Use the sqlite3VdbeRewind() procedure to restore a virtual machine back
+** to its initial state after it has been run.
+*/
+void sqlite3VdbeMakeReady(
+  Vdbe *p,                       /* The VDBE */
+  Parse *pParse                  /* Parsing context */
+){
+  sqlite3 *db;                   /* The database connection */
+  int nVar;                      /* Number of parameters */
+  int nMem;                      /* Number of VM memory registers */
+  int nCursor;                   /* Number of cursors required */
+  int nArg;                      /* Number of arguments in subprograms */
+  int n;                         /* Loop counter */
+  u8 *zCsr;                      /* Memory available for allocation */
+  u8 *zEnd;                      /* First byte past allocated memory */
+  int nByte;                     /* How much extra memory is needed */
+
+  assert( p!=0 );
+  assert( p->nOp>0 );
+  assert( pParse!=0 );
+  assert( p->magic==VDBE_MAGIC_INIT );
+  db = p->db;
+  assert( db->mallocFailed==0 );
+  nVar = pParse->nVar;
+  nMem = pParse->nMem;
+  nCursor = pParse->nTab;
+  nArg = pParse->nMaxArg;
+  
   /* For each cursor required, also allocate a memory cell. Memory
   ** cells (nMem+1-nCursor)..nMem, inclusive, will never be used by
   ** the vdbe program. Instead they are used to allocate space for
@@ -1441,91 +1485,68 @@ void sqlite3VdbeMakeReady(
   nMem += nCursor;
 
   /* Allocate space for memory registers, SQL variables, VDBE cursors and 
-  ** an array to marshal SQL function arguments in. This is only done the
-  ** first time this function is called for a given VDBE, not when it is
-  ** being called from sqlite3_reset() to reset the virtual machine.
+  ** an array to marshal SQL function arguments in.
   */
-  if( nVar>=0 && ALWAYS(db->mallocFailed==0) ){
-    u8 *zCsr = (u8 *)&p->aOp[p->nOp];       /* Memory avaliable for alloation */
-    u8 *zEnd = (u8 *)&p->aOp[p->nOpAlloc];  /* First byte past available mem */
-    int nByte;                              /* How much extra memory needed */
+  zCsr = (u8*)&p->aOp[p->nOp];       /* Memory avaliable for allocation */
+  zEnd = (u8*)&p->aOp[p->nOpAlloc];  /* First byte past end of zCsr[] */
 
-    resolveP2Values(p, &nArg);
-    p->usesStmtJournal = (u8)usesStmtJournal;
-    if( isExplain && nMem<10 ){
-      nMem = 10;
+  resolveP2Values(p, &nArg);
+  p->usesStmtJournal = (u8)(pParse->isMultiWrite && pParse->mayAbort);
+  if( pParse->explain && nMem<10 ){
+    nMem = 10;
+  }
+  memset(zCsr, 0, zEnd-zCsr);
+  zCsr += (zCsr - (u8*)0)&7;
+  assert( EIGHT_BYTE_ALIGNMENT(zCsr) );
+
+  /* Memory for registers, parameters, cursor, etc, is allocated in two
+  ** passes.  On the first pass, we try to reuse unused space at the 
+  ** end of the opcode array.  If we are unable to satisfy all memory
+  ** requirements by reusing the opcode array tail, then the second
+  ** pass will fill in the rest using a fresh allocation.  
+  **
+  ** This two-pass approach that reuses as much memory as possible from
+  ** the leftover space at the end of the opcode array can significantly
+  ** reduce the amount of memory held by a prepared statement.
+  */
+  do {
+    nByte = 0;
+    p->aMem = allocSpace(p->aMem, nMem*sizeof(Mem), &zCsr, zEnd, &nByte);
+    p->aVar = allocSpace(p->aVar, nVar*sizeof(Mem), &zCsr, zEnd, &nByte);
+    p->apArg = allocSpace(p->apArg, nArg*sizeof(Mem*), &zCsr, zEnd, &nByte);
+    p->azVar = allocSpace(p->azVar, nVar*sizeof(char*), &zCsr, zEnd, &nByte);
+    p->apCsr = allocSpace(p->apCsr, nCursor*sizeof(VdbeCursor*),
+                          &zCsr, zEnd, &nByte);
+    if( nByte ){
+      p->pFree = sqlite3DbMallocZero(db, nByte);
     }
-    memset(zCsr, 0, zEnd-zCsr);
-    zCsr += (zCsr - (u8*)0)&7;
-    assert( EIGHT_BYTE_ALIGNMENT(zCsr) );
+    zCsr = p->pFree;
+    zEnd = &zCsr[nByte];
+  }while( nByte && !db->mallocFailed );
 
-    /* Memory for registers, parameters, cursor, etc, is allocated in two
-    ** passes.  On the first pass, we try to reuse unused space at the 
-    ** end of the opcode array.  If we are unable to satisfy all memory
-    ** requirements by reusing the opcode array tail, then the second
-    ** pass will fill in the rest using a fresh allocation.  
-    **
-    ** This two-pass approach that reuses as much memory as possible from
-    ** the leftover space at the end of the opcode array can significantly
-    ** reduce the amount of memory held by a prepared statement.
-    */
-    do {
-      nByte = 0;
-      p->aMem = allocSpace(p->aMem, nMem*sizeof(Mem), &zCsr, zEnd, &nByte);
-      p->aVar = allocSpace(p->aVar, nVar*sizeof(Mem), &zCsr, zEnd, &nByte);
-      p->apArg = allocSpace(p->apArg, nArg*sizeof(Mem*), &zCsr, zEnd, &nByte);
-      p->azVar = allocSpace(p->azVar, nVar*sizeof(char*), &zCsr, zEnd, &nByte);
-      p->apCsr = allocSpace(p->apCsr, nCursor*sizeof(VdbeCursor*),
-                            &zCsr, zEnd, &nByte);
-      if( nByte ){
-        p->pFree = sqlite3DbMallocZero(db, nByte);
-      }
-      zCsr = p->pFree;
-      zEnd = &zCsr[nByte];
-    }while( nByte && !db->mallocFailed );
-
-    p->nCursor = (u16)nCursor;
-    if( p->aVar ){
-      p->nVar = (ynVar)nVar;
-      for(n=0; n<nVar; n++){
-        p->aVar[n].flags = MEM_Null;
-        p->aVar[n].db = db;
-      }
-    }
-    if( p->aMem ){
-      p->aMem--;                      /* aMem[] goes from 1..nMem */
-      p->nMem = nMem;                 /*       not from 0..nMem-1 */
-      for(n=1; n<=nMem; n++){
-        p->aMem[n].flags = MEM_Null;
-        p->aMem[n].db = db;
-      }
+  p->nCursor = (u16)nCursor;
+  if( p->aVar ){
+    p->nVar = (ynVar)nVar;
+    for(n=0; n<nVar; n++){
+      p->aVar[n].flags = MEM_Null;
+      p->aVar[n].db = db;
     }
   }
-#ifdef SQLITE_DEBUG
-  for(n=1; n<p->nMem; n++){
-    assert( p->aMem[n].db==db );
+  if( p->azVar ){
+    p->nzVar = pParse->nzVar;
+    memcpy(p->azVar, pParse->azVar, p->nzVar*sizeof(p->azVar[0]));
+    memset(pParse->azVar, 0, pParse->nzVar*sizeof(pParse->azVar[0]));
   }
-#endif
-
-  p->pc = -1;
-  p->rc = SQLITE_OK;
-  p->errorAction = OE_Abort;
-  p->explain |= isExplain;
-  p->magic = VDBE_MAGIC_RUN;
-  p->nChange = 0;
-  p->cacheCtr = 1;
-  p->minWriteFileFormat = 255;
-  p->iStatement = 0;
-  p->nFkConstraint = 0;
-#ifdef VDBE_PROFILE
-  {
-    int i;
-    for(i=0; i<p->nOp; i++){
-      p->aOp[i].cnt = 0;
-      p->aOp[i].cycles = 0;
+  if( p->aMem ){
+    p->aMem--;                      /* aMem[] goes from 1..nMem */
+    p->nMem = nMem;                 /*       not from 0..nMem-1 */
+    for(n=1; n<=nMem; n++){
+      p->aMem[n].flags = MEM_Null;
+      p->aMem[n].db = db;
     }
   }
-#endif
+  p->explain = pParse->explain;
+  sqlite3VdbeRewind(p);
 }
 
 /*
@@ -2399,6 +2420,7 @@ void sqlite3VdbeDeleteAuxData(VdbeFunc *pVdbeFunc, int mask){
 */
 void sqlite3VdbeDeleteObject(sqlite3 *db, Vdbe *p){
   SubProgram *pSub, *pNext;
+  int i;
   assert( p->db==0 || p->db==db );
   releaseMemArray(p->aVar, p->nVar);
   releaseMemArray(p->aColName, p->nResColumn*COLNAME_N);
@@ -2407,6 +2429,7 @@ void sqlite3VdbeDeleteObject(sqlite3 *db, Vdbe *p){
     vdbeFreeOpArray(db, pSub->aOp, pSub->nOp);
     sqlite3DbFree(db, pSub);
   }
+  for(i=p->nzVar-1; i>=0; i--) sqlite3DbFree(db, p->azVar[i]);
   vdbeFreeOpArray(db, p->aOp, p->nOp);
   sqlite3DbFree(db, p->aLabel);
   sqlite3DbFree(db, p->aColName);
diff --git a/src/vdbeblob.c b/src/vdbeblob.c
index 18fdd465ae..a8728e6d25 100644
--- a/src/vdbeblob.c
+++ b/src/vdbeblob.c
@@ -297,7 +297,10 @@ int sqlite3_blob_open(
       sqlite3VdbeChangeP4(v, 3+flags, SQLITE_INT_TO_PTR(pTab->nCol+1),P4_INT32);
       sqlite3VdbeChangeP2(v, 7, pTab->nCol);
       if( !db->mallocFailed ){
-        sqlite3VdbeMakeReady(v, 1, 1, 1, 0, 0, 0);
+        pParse->nVar = 1;
+        pParse->nMem = 1;
+        pParse->nTab = 1;
+        sqlite3VdbeMakeReady(v, pParse);
       }
     }
    

From 04e9eeadc63bb651a658150e0529cd3463914690 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Wed, 1 Jun 2011 19:16:06 +0000
Subject: [PATCH 15/30] Avoid unnecessary duplication of SQL parameter names.

FossilOrigin-Name: e704e8690ae35decc9769a45cf8d519ccad8b79d
---
 manifest      | 14 +++++++-------
 manifest.uuid |  2 +-
 src/expr.c    |  4 +++-
 src/vdbe.c    |  1 +
 4 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/manifest b/manifest
index b747a1409f..9e6489e647 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Refactor\sthe\sSQL\sparameter\sprocessing\sso\sthat\sparameter\snames\sfor\svalues\nthat\sare\soptimized\sout\sof\sthe\sprepare\sstatement\sare\snot\sforgotten.
-D 2011-06-01T18:15:55.858
+C Avoid\sunnecessary\sduplication\sof\sSQL\sparameter\snames.
+D 2011-06-01T19:16:06.364
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -131,7 +131,7 @@ F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c 7deec4534f3b5a0c3b4a4cbadf809d321f64f9c4
 F src/date.c 1548fdac51377e4e7833251de878b4058c148e1b
 F src/delete.c cecc926c70783452f3e8eb452c728291ce1a0b21
-F src/expr.c c33584bcf4ee011e28ff74e4dcef02da1dc09dd6
+F src/expr.c ab46ab0f0c44979a8164ca31728d7d10ae5e8106
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c a43ba8a005fb5efd1deeee06853e3a6120d46a91
 F src/func.c b9117e40975245b8504cf3625d7e321d8d4b63dc
@@ -236,7 +236,7 @@ F src/update.c 5bcb56e5c7380a2eecb0e71891dbd4ad7437748f
 F src/utf.c d83650c3ea08f7407bd9d0839d9885241c209c60
 F src/util.c 0f33bbbdfcc4a2d8cf20c3b2a16ffc3b57c58a70
 F src/vacuum.c 05513dca036a1e7848fe18d5ed1265ac0b32365e
-F src/vdbe.c 103827f560cdc48b1d455ce4d4b3573dd88f9ab4
+F src/vdbe.c 2ec37637fa70ab0c694d8327ee5dcedbc0621524
 F src/vdbe.h d9c6123384189dc37d27beac1bf44688aa75b6cb
 F src/vdbeInt.h ad84226cc0adcb1185c22b70696b235a1678bb45
 F src/vdbeapi.c 0eeadc75e44a30efd996d6af6e7c5a2488e35be8
@@ -938,7 +938,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P a0ae314c7f41d0146a9ee1adc576cd977219a378
-R d99e1065a540709b7ea760de89dbcfd0
+P b3aaf715b60b8a338cc6c92dad1ead4a3f7146a3
+R 018490a374b5cf414074a5a4bbd3de70
 U drh
-Z ce5ce2791f47aa05a4daaafded206f56
+Z dcf10ad87997753baf45956f9011da61
diff --git a/manifest.uuid b/manifest.uuid
index 4597483a7e..de373954a3 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-b3aaf715b60b8a338cc6c92dad1ead4a3f7146a3
\ No newline at end of file
+e704e8690ae35decc9769a45cf8d519ccad8b79d
\ No newline at end of file
diff --git a/src/expr.c b/src/expr.c
index 4cd2f24551..be2f4d7c66 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2345,7 +2345,9 @@ int sqlite3ExprCodeTarget(Parse *pParse, Expr *pExpr, int target){
       assert( pExpr->u.zToken[0]!=0 );
       sqlite3VdbeAddOp2(v, OP_Variable, pExpr->iColumn, target);
       if( pExpr->u.zToken[1]!=0 ){
-        sqlite3VdbeChangeP4(v, -1, pExpr->u.zToken, P4_TRANSIENT);
+        assert( pExpr->u.zToken[0]=='?' 
+             || strcmp(pExpr->u.zToken, pParse->azVar[pExpr->iColumn-1])==0 );
+        sqlite3VdbeChangeP4(v, -1, pParse->azVar[pExpr->iColumn-1], P4_STATIC);
       }
       break;
     }
diff --git a/src/vdbe.c b/src/vdbe.c
index eea6aba70e..439fe72540 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -988,6 +988,7 @@ case OP_Variable: {            /* out2-prerelease */
   Mem *pVar;       /* Value being transferred */
 
   assert( pOp->p1>0 && pOp->p1<=p->nVar );
+  assert( pOp->p4.z==0 || pOp->p4.z==p->azVar[pOp->p1-1] );
   pVar = &p->aVar[pOp->p1 - 1];
   if( sqlite3VdbeMemTooBig(pVar) ){
     goto too_big;

From 66dfec8b7a6052d4b639e5ab1910249aebb8828d Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Wed, 1 Jun 2011 20:01:49 +0000
Subject: [PATCH 16/30] Simplify the wal-readonly branch so that it does not
 require changes to anything other than os_unix.c and wal.c and a couple of
 new error codes.

FossilOrigin-Name: d6b4709de4d1f8af001f58938247f00a652a616e
---
 manifest        | 30 ++++++++++-----------
 manifest.uuid   |  2 +-
 src/attach.c    |  6 ++---
 src/btree.h     |  1 -
 src/main.c      | 18 ++-----------
 src/os_unix.c   | 69 ++++++++++++++++++++-----------------------------
 src/pager.c     |  7 ++---
 src/pager.h     |  1 -
 src/sqlite.h.in | 41 +----------------------------
 src/sqliteInt.h |  2 +-
 src/wal.c       | 62 ++++++++++++++------------------------------
 src/wal.h       |  4 +--
 12 files changed, 74 insertions(+), 169 deletions(-)

diff --git a/manifest b/manifest
index b3a84d3a3f..8b6e11236e 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Pull\sthe\slatest\strunk\schanges\sinto\sthe\swal-readonly\sbranch.
-D 2011-06-01T19:44:57.308
+C Simplify\sthe\swal-readonly\sbranch\sso\sthat\sit\sdoes\snot\srequire\schanges\sto\nanything\sother\sthan\sos_unix.c\sand\swal.c\sand\sa\scouple\sof\snew\serror\scodes.
+D 2011-06-01T20:01:49.650
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -117,13 +117,13 @@ F sqlite3.1 6be1ad09113570e1fc8dcaff84c9b0b337db5ffc
 F sqlite3.pc.in ae6f59a76e862f5c561eb32a380228a02afc3cad
 F src/alter.c 280f5c04b11b492703a342222b3de0a999445280
 F src/analyze.c a425d62e8fa9ebcb4359ab84ff0c62c6563d2e2a
-F src/attach.c a87bfb77a720f7aa02791434aacfd9bc8feb50cc
+F src/attach.c 12c6957996908edc31c96d7c68d4942c2474405f
 F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
 F src/backup.c 986c15232757f2873dff35ee3b35cbf935fc573c
 F src/bitvec.c af50f1c8c0ff54d6bdb7a80e2fceca5a93670bef
 F src/btmutex.c 976f45a12e37293e32cae0281b15a21d48a8aaa7
 F src/btree.c 0d3b39dcb79565c053e35fc12713f12d8a74d6a9
-F src/btree.h d796dc4030b3cce7f5a0cc4f2f986d2befa6b8ac
+F src/btree.h f5d775cd6cfc7ac32a2535b70e8d2af48ef5f2ce
 F src/btreeInt.h 67978c014fa4f7cc874032dd3aacadd8db656bc3
 F src/build.c c10ab9e2c77ade99dee23554787f8acfc0c231fc
 F src/callback.c 0425c6320730e6d3981acfb9202c1bed9016ad1a
@@ -144,7 +144,7 @@ F src/journal.c 552839e54d1bf76fb8f7abe51868b66acacf6a0e
 F src/legacy.c a199d7683d60cef73089e892409113e69c23a99f
 F src/lempar.c 7f026423f4d71d989e719a743f98a1cbd4e6d99e
 F src/loadext.c 3ae0d52da013a6326310655be6473fd472347b85
-F src/main.c 4e55ff4800181e3ad063492740f54ce406de5deb
+F src/main.c 059daeed5876b3604f0192f838faf5f4db138901
 F src/malloc.c 591aedb20ae40813f1045f2ef253438a334775d9
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c 00bd8265c81abb665c48fea1e0c234eb3b922206
@@ -163,10 +163,10 @@ F src/os.c 22ac61d06e72a0dac900400147333b07b13d8e1d
 F src/os.h 9dbed8c2b9c1f2f2ebabc09e49829d4777c26bf9
 F src/os_common.h a8f95b81eca8a1ab8593d23e94f8a35f35d4078f
 F src/os_os2.c 4a75888ba3dfc820ad5e8177025972d74d7f2440
-F src/os_unix.c af3c3f6a0fc6dbde802e55848f1cad7fb2121ff3
+F src/os_unix.c a59c0718021934157f235468788c793cbc0d53de
 F src/os_win.c 218b899469e570d46eb8147c2383075f7c026230
-F src/pager.c 2cf3bad86e6fbac42d9dbd3b89799185a343b17b
-F src/pager.h 34c6b029446f06f40847746d22faac0d354dd909
+F src/pager.c 120550e7ef01dafaa2cbb4a0528c0d87c8f12b41
+F src/pager.h 3f8c783de1d4706b40b1ac15b64f5f896bcc78d1
 F src/parse.y 12b7ebd61ea54f0e1b1083ff69cc2c8ce9353d58
 F src/pcache.c 49e718c095810c6b3334e3a6d89970aceaddefce
 F src/pcache.h c683390d50f856d4cd8e24342ae62027d1bb6050
@@ -179,9 +179,9 @@ F src/resolve.c 1c0f32b64f8e3f555fe1f732f9d6f501a7f05706
 F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
 F src/select.c d9d440809025a58547e39f4f268c2a296bfb56ff
 F src/shell.c decd04236a7ef26be5ef46d4ea963044bfad9a48
-F src/sqlite.h.in dbe88418628302c0a93671a216346acb5746211a
+F src/sqlite.h.in 2f51e4f58b2b4626fcbd9938580e730cb5fb4985
 F src/sqlite3ext.h c90bd5507099f62043832d73f6425d8d5c5da754
-F src/sqliteInt.h 219b21e80f46eef7cc7bb7477c12de61d00f5607
+F src/sqliteInt.h 6e58c558c57c8f44011736d5fa5295eb3130f9de
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac64842c86cec2fc1a1d0e5c16d3beb8ad332bf
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -245,8 +245,8 @@ F src/vdbeblob.c f024f0bf420f36b070143c32b15cc7287341ffd3
 F src/vdbemem.c 0498796b6ffbe45e32960d6a1f5adfb6e419883b
 F src/vdbetrace.c 5d0dc3d5fd54878cc8d6d28eb41deb8d5885b114
 F src/vtab.c 9ba8c7fdb7d39260c033a402f6032d3e7bc5d336
-F src/wal.c 861ea98779dac3867e5f97d13e61cbbb39b310b0
-F src/wal.h 0835021ae243c2f1119e997e8af5d8cc3b991de1
+F src/wal.c fd63d07233203dd3bd29cbe1ae5c8bb2c34e08fc
+F src/wal.h 66b40bd91bc29a5be1c88ddd1f5ade8f3f48728a
 F src/walker.c 3112bb3afe1d85dc52317cb1d752055e9a781f8f
 F src/where.c 55403ce19c506be6a321c7f129aff693d6103db5
 F test/8_3_names.test b93687beebd17f6ebf812405a6833bae5d1f4199
@@ -939,7 +939,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 2c6b5a28e3f6b7cb96b944d0a254f3707885f1ce e704e8690ae35decc9769a45cf8d519ccad8b79d
-R 5f4edf2ff77d011b562e3dc234f8f21d
+P 0b63b71357a65e26ecd3f3bb34a5f14feee322f4
+R 20a045d8e6470f5f17b67b2f15ff8859
 U drh
-Z 99212444a62258034d706d358ee0a50e
+Z f7b3b70c555e3fb5f3360ed8e60c2877
diff --git a/manifest.uuid b/manifest.uuid
index 70ad59250f..6f393899aa 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-0b63b71357a65e26ecd3f3bb34a5f14feee322f4
\ No newline at end of file
+d6b4709de4d1f8af001f58938247f00a652a616e
\ No newline at end of file
diff --git a/src/attach.c b/src/attach.c
index 4b8ea77917..18f8823b31 100644
--- a/src/attach.c
+++ b/src/attach.c
@@ -76,8 +76,6 @@ static void attachFunc(
   Db *aNew;
   char *zErrDyn = 0;
   sqlite3_vfs *pVfs;
-  const char *zVfs = db->pVfs->zName;       /* Name of default (main) VFS */
-  int btflags = 0;
 
   UNUSED_PARAMETER(NotUsed);
 
@@ -131,7 +129,7 @@ static void attachFunc(
   ** or may not be initialised.
   */
   flags = db->openFlags;
-  rc = sqlite3ParseUri(zVfs, zFile, &flags, &btflags, &pVfs, &zPath, &zErr);
+  rc = sqlite3ParseUri(db->pVfs->zName, zFile, &flags, &pVfs, &zPath, &zErr);
   if( rc!=SQLITE_OK ){
     if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
     sqlite3_result_error(context, zErr, -1);
@@ -140,7 +138,7 @@ static void attachFunc(
   }
   assert( pVfs );
   flags |= SQLITE_OPEN_MAIN_DB;
-  rc = sqlite3BtreeOpen(pVfs, zPath, db, &aNew->pBt, btflags, flags);
+  rc = sqlite3BtreeOpen(pVfs, zPath, db, &aNew->pBt, 0, flags);
   sqlite3_free( zPath );
   db->nDb++;
   if( rc==SQLITE_CONSTRAINT ){
diff --git a/src/btree.h b/src/btree.h
index c5abc9c865..9e3a73b3b6 100644
--- a/src/btree.h
+++ b/src/btree.h
@@ -61,7 +61,6 @@ int sqlite3BtreeOpen(
 #define BTREE_MEMORY        4  /* This is an in-memory DB */
 #define BTREE_SINGLE        8  /* The file contains at most 1 b-tree */
 #define BTREE_UNORDERED    16  /* Use of a hash implementation is OK */
-#define BTREE_READONLYSHM  32  /* Read-only SHM access is acceptable */
 
 int sqlite3BtreeClose(Btree*);
 int sqlite3BtreeSetCacheSize(Btree*,int);
diff --git a/src/main.c b/src/main.c
index cdd54b659d..c99d396546 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1803,11 +1803,6 @@ int sqlite3_limit(sqlite3 *db, int limitId, int newLimit){
 ** *pFlags may be updated before returning if the URI filename contains 
 ** "cache=xxx" or "mode=xxx" query parameters.
 **
-** The third argument, pBtflags, points to an integer containing the flags
-** that will be passed as the 5th argument to sqlite3BtreeOpen (BTREE_XXX
-** flags). This value will be edited if the URI filename contains a
-** "readonly_shm=1" or "readonly_shm=0" query parameter.
-**
 ** If successful, SQLITE_OK is returned. In this case *ppVfs is set to point to
 ** the VFS that should be used to open the database file. *pzFile is set to
 ** point to a buffer containing the name of the file to open. It is the 
@@ -1823,7 +1818,6 @@ int sqlite3ParseUri(
   const char *zDefaultVfs,        /* VFS to use if no "vfs=xxx" query option */
   const char *zUri,               /* Nul-terminated URI to parse */
   unsigned int *pFlags,           /* IN/OUT: SQLITE_OPEN_XXX flags */
-  int *pBtflags,                  /* IN/OUT: BTREE_XXX flags */
   sqlite3_vfs **ppVfs,            /* OUT: VFS to use */ 
   char **pzFile,                  /* OUT: Filename component of URI */
   char **pzErrMsg                 /* OUT: Error message (if rc!=SQLITE_OK) */
@@ -1939,12 +1933,6 @@ int sqlite3ParseUri(
 
       if( nOpt==3 && memcmp("vfs", zOpt, 3)==0 ){
         zVfs = zVal;
-      }else if( nOpt==12 && memcmp("readonly_shm", zOpt, 12)==0 ){
-        if( sqlite3Atoi(zVal) ){
-          *pBtflags |= BTREE_READONLYSHM;
-        }else{
-          *pBtflags &= ~BTREE_READONLYSHM;
-        }
       }else{
         struct OpenMode {
           const char *z;
@@ -2048,7 +2036,6 @@ static int openDatabase(
   int isThreadsafe;               /* True for threadsafe connections */
   char *zOpen = 0;                /* Filename argument to pass to BtreeOpen() */
   char *zErrMsg = 0;              /* Error message from sqlite3ParseUri() */
-  int btflags = 0;                /* Mask of BTREE_XXX flags */
 
   *ppDb = 0;
 #ifndef SQLITE_OMIT_AUTOINIT
@@ -2177,8 +2164,7 @@ static int openDatabase(
 
   /* Parse the filename/URI argument. */
   db->openFlags = flags;
-  rc = sqlite3ParseUri(
-      zVfs, zFilename, &flags, &btflags, &db->pVfs, &zOpen, &zErrMsg);
+  rc = sqlite3ParseUri(zVfs, zFilename, &flags, &db->pVfs, &zOpen, &zErrMsg);
   if( rc!=SQLITE_OK ){
     if( rc==SQLITE_NOMEM ) db->mallocFailed = 1;
     sqlite3Error(db, rc, zErrMsg ? "%s" : 0, zErrMsg);
@@ -2187,7 +2173,7 @@ static int openDatabase(
   }
 
   /* Open the backend database driver */
-  rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, btflags,
+  rc = sqlite3BtreeOpen(db->pVfs, zOpen, db, &db->aDb[0].pBt, 0,
                         flags | SQLITE_OPEN_MAIN_DB);
   if( rc!=SQLITE_OK ){
     if( rc==SQLITE_IOERR_NOMEM ){
diff --git a/src/os_unix.c b/src/os_unix.c
index 947f431aeb..e6d1774a49 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -212,7 +212,6 @@ struct unixFile {
   UnixUnusedFd *pUnused;              /* Pre-allocated UnixUnusedFd */
   const char *zPath;                  /* Name of the file */
   unixShm *pShm;                      /* Shared memory segment information */
-  int readOnlyShm;                    /* True to open shared-memory read-only */
   int szChunk;                        /* Configured by FCNTL_CHUNK_SIZE */
 #if SQLITE_ENABLE_LOCKING_STYLE
   int openFlags;                      /* The flags specified at open() */
@@ -3453,10 +3452,6 @@ static int unixFileControl(sqlite3_file *id, int op, void *pArg){
     case SQLITE_FCNTL_SIZE_HINT: {
       return fcntlSizeHint((unixFile *)id, *(i64 *)pArg);
     }
-    case SQLITE_FCNTL_READONLY_SHM: {
-      ((unixFile*)id)->readOnlyShm = (pArg!=0);
-      return SQLITE_OK;
-    }
 #ifndef NDEBUG
     /* The pager calls this method to signal that it has done
     ** a rollback and that the database is therefore unchanged and
@@ -3542,11 +3537,11 @@ struct unixShmNode {
   char *zFilename;           /* Name of the mmapped file */
   int h;                     /* Open file descriptor */
   int szRegion;              /* Size of shared-memory regions */
-  int nRegion;               /* Size of array apRegion */
+  u16 nRegion;               /* Size of array apRegion */
+  u8 isReadonly;             /* True if read-only */
   char **apRegion;           /* Array of mapped shared-memory regions */
   int nRef;                  /* Number of unixShm objects pointing to this */
   unixShm *pFirst;           /* All unixShm objects pointing to this */
-  u8 readOnly;               /* True if this is a read-only mapping */
 #ifdef SQLITE_DEBUG
   u8 exclMask;               /* Mask of exclusive locks held */
   u8 sharedMask;             /* Mask of shared locks held */
@@ -3787,48 +3782,38 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
     }
 
     if( pInode->bProcessLock==0 ){
-      int flags = (pDbFd->readOnlyShm ? O_RDONLY : O_RDWR|O_CREAT);
-      pShmNode->h = robust_open(zShmFilename, flags, (sStat.st_mode & 0777));
+      pShmNode->h = robust_open(zShmFilename, O_RDWR|O_CREAT,
+                               (sStat.st_mode & 0777));
       if( pShmNode->h<0 ){
-        rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShmFilename);
-        goto shm_open_err;
+        const char *zRO;
+        zRO = sqlite3_uri_parameter(pDbFd->zPath, "readonly_shm");
+        if( zRO && (zRO[0]!='0' || zRO[1]!=0) ){
+          pShmNode->h = robust_open(zShmFilename, O_RDONLY,
+                                    (sStat.st_mode & 0777));
+          pShmNode->isReadonly = 1;
+        }
+        if( pShmNode->h<0 ){
+          rc = unixLogError(SQLITE_CANTOPEN_BKPT, "open", zShmFilename);
+          goto shm_open_err;
+        }
       }
-      pShmNode->readOnly = pDbFd->readOnlyShm;
   
       /* Check to see if another process is holding the dead-man switch.
-      ** If not, zero the first few bytes of the shared-memory file to make
-      ** sure it is not mistaken for valid by code in wal.c. Except, if this 
-      ** is a read-only connection to the shared-memory then it is not possible
-      ** to check check if another process is holding a read-lock on the DMS
-      ** byte, as we cannot attempt a write-lock via a read-only file 
-      ** descriptor. So in this case, we just assume the shared-memory 
-      ** contents are Ok and proceed.  */
-      if( pShmNode->readOnly==0 ){
-        rc = SQLITE_OK;
-        if( unixShmSystemLock(pShmNode, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
-          if( pDbFd->readOnlyShm ){
-            rc = SQLITE_IOERR_SHMOPEN;
-          }else if( 4!=osWrite(pShmNode->h, "\00\00\00\00", 4) ){
-            rc = unixLogError(SQLITE_IOERR_SHMOPEN, "ftruncate", zShmFilename);
-          }
+      ** If not, truncate the file to zero length. 
+      */
+      rc = SQLITE_OK;
+      if( unixShmSystemLock(pShmNode, F_WRLCK, UNIX_SHM_DMS, 1)==SQLITE_OK ){
+        if( robust_ftruncate(pShmNode->h, 0) ){
+          rc = unixLogError(SQLITE_IOERR_SHMOPEN, "ftruncate", zShmFilename);
         }
-        if( rc==SQLITE_OK ){
-          rc = unixShmSystemLock(pShmNode, F_RDLCK, UNIX_SHM_DMS, 1);
-        }
-        if( rc ) goto shm_open_err;
       }
+      if( rc==SQLITE_OK ){
+        rc = unixShmSystemLock(pShmNode, F_RDLCK, UNIX_SHM_DMS, 1);
+      }
+      if( rc ) goto shm_open_err;
     }
   }
 
-  /* If the unixShmNode is read-only, but SQLITE_FCNTL_READONLY_SHM has not
-  ** been set for file-descriptor pDbFd, return an error. The wal.c module
-  ** will then call this function again with SQLITE_FCNTL_READONLY_SHM set.
-  */
-  else if( pShmNode->readOnly && !pDbFd->readOnlyShm ){
-    rc = SQLITE_IOERR_SHMOPEN;
-    goto shm_open_err;
-  }
-
   /* Make the new connection a child of the unixShmNode */
   p->pShmNode = pShmNode;
 #ifdef SQLITE_DEBUG
@@ -3949,7 +3934,8 @@ static int unixShmMap(
     while(pShmNode->nRegion<=iRegion){
       void *pMem;
       if( pShmNode->h>=0 ){
-        pMem = mmap(0, szRegion, PROT_READ|(!pShmNode->readOnly?PROT_WRITE:0), 
+        pMem = mmap(0, szRegion,
+            pShmNode->isReadonly ? PROT_READ : PROT_READ|PROT_WRITE, 
             MAP_SHARED, pShmNode->h, pShmNode->nRegion*szRegion
         );
         if( pMem==MAP_FAILED ){
@@ -3975,6 +3961,7 @@ shmpage_out:
   }else{
     *pp = 0;
   }
+  if( pShmNode->isReadonly && rc==SQLITE_OK ) rc = SQLITE_READONLY;
   sqlite3_mutex_leave(pShmNode->mutex);
   return rc;
 }
diff --git a/src/pager.c b/src/pager.c
index 461c735432..7ff9a9a000 100644
--- a/src/pager.c
+++ b/src/pager.c
@@ -620,7 +620,6 @@ struct Pager {
   u8 tempFile;                /* zFilename is a temporary file */
   u8 readOnly;                /* True for a read-only database */
   u8 memDb;                   /* True to inhibit all file I/O */
-  u8 readOnlyShm;             /* True if read-only shm access is Ok */
 
   /**************************************************************************
   ** The following block contains those class members that change during
@@ -3018,7 +3017,6 @@ static int pagerWalFrames(
 static int pagerBeginReadTransaction(Pager *pPager){
   int rc;                         /* Return code */
   int changed = 0;                /* True if cache must be reset */
-  Wal *pWal = pPager->pWal;
 
   assert( pagerUseWal(pPager) );
   assert( pPager->eState==PAGER_OPEN || pPager->eState==PAGER_READER );
@@ -3028,9 +3026,9 @@ static int pagerBeginReadTransaction(Pager *pPager){
   ** are in locking_mode=NORMAL and EndRead() was previously called,
   ** the duplicate call is harmless.
   */
-  sqlite3WalEndReadTransaction(pWal);
+  sqlite3WalEndReadTransaction(pPager->pWal);
 
-  rc = sqlite3WalBeginReadTransaction(pWal, pPager->readOnlyShm, &changed);
+  rc = sqlite3WalBeginReadTransaction(pPager->pWal, &changed);
   if( rc!=SQLITE_OK || changed ){
     pager_reset(pPager);
   }
@@ -4418,7 +4416,6 @@ int sqlite3PagerOpen(
   }
   pPager->pVfs = pVfs;
   pPager->vfsFlags = vfsFlags;
-  pPager->readOnlyShm = (flags & PAGER_READONLYSHM)!=0;
 
   /* Open the pager file.
   */
diff --git a/src/pager.h b/src/pager.h
index c6cb8bcb55..eab7ddaf80 100644
--- a/src/pager.h
+++ b/src/pager.h
@@ -60,7 +60,6 @@ typedef struct PgHdr DbPage;
 #define PAGER_OMIT_JOURNAL  0x0001    /* Do not use a rollback journal */
 #define PAGER_NO_READLOCK   0x0002    /* Omit readlocks on readonly files */
 #define PAGER_MEMORY        0x0004    /* In-memory database */
-#define PAGER_READONLYSHM   0x0020    /* Read-only SHM access is acceptable */
 
 /*
 ** Valid values for the second argument to sqlite3PagerLockingMode().
diff --git a/src/sqlite.h.in b/src/sqlite.h.in
index 45aec0e1c2..593e9148fe 100644
--- a/src/sqlite.h.in
+++ b/src/sqlite.h.in
@@ -454,7 +454,6 @@ int sqlite3_exec(
 #define SQLITE_BUSY_RECOVERY           (SQLITE_BUSY   |  (1<<8))
 #define SQLITE_CANTOPEN_NOTEMPDIR      (SQLITE_CANTOPEN | (1<<8))
 #define SQLITE_CORRUPT_VTAB            (SQLITE_CORRUPT | (1<<8))
-
 #define SQLITE_READONLY_RECOVERY       (SQLITE_READONLY | (1<<8))
 #define SQLITE_READONLY_CANTLOCK       (SQLITE_READONLY | (2<<8))
 
@@ -737,27 +736,6 @@ struct sqlite3_io_methods {
 ** Applications should not call [sqlite3_file_control()] with this
 ** opcode as doing so may disrupt the operation of the specialized VFSes
 ** that do require it.  
-**
-** The [SQLITE_FCNTL_READONLY_SHM] may be generated internally by SQLite if
-** the "readonly_shm=1" URI option is specified when the database is opened.
-** The fourth argument passed to the VFS xFileControl methods is a pointer
-** to a variable of type "int" containing the value 1 or 0. If the variable
-** contains the value 1, then this indicates to the VFS that a read-only
-** mapping of the shared-memory region is acceptable. If it is set to 0, then
-** this indicates that a read-write mapping is required (as normal). If
-** a read-only mapping is returned, then the VFS may also return read-only
-** mappings for any subsequent requests via the same file-descriptor -
-** regardless of the value most recently configured using
-** SQLITE_FCNTL_READONLY_SHM.
-**
-** In practice, if "readonly_shm=1" is specified and the first attempt to
-** map a shared-memory region fails, then this file-control is invoked with
-** the argument variable set to 1 and a second attempt to map the shared-memory
-** region is made. If this mapping succeeds, then the connection continues
-** with the read-only mapping. Otherwise, if it fails, SQLITE_CANTOPEN is
-** returned to the caller. Whether or not the second (read-only) mapping
-** attempt succeeds, the file-control is invoked again with the argument
-** variable set to 0.
 */
 #define SQLITE_FCNTL_LOCKSTATE        1
 #define SQLITE_GET_LOCKPROXYFILE      2
@@ -767,7 +745,6 @@ struct sqlite3_io_methods {
 #define SQLITE_FCNTL_CHUNK_SIZE       6
 #define SQLITE_FCNTL_FILE_POINTER     7
 #define SQLITE_FCNTL_SYNC_OMITTED     8
-#define SQLITE_FCNTL_READONLY_SHM     9
 
 
 /*
@@ -2481,7 +2458,7 @@ void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
 ** [[core URI query parameters]]
 ** The query component of a URI may contain parameters that are interpreted
 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
-** SQLite interprets the following four query parameters:
+** SQLite interprets the following three query parameters:
 **
 ** <ul>
 **   <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
@@ -2513,22 +2490,6 @@ void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
 **     ^If sqlite3_open_v2() is used and the "cache" parameter is present in
 **     a URI filename, its value overrides any behaviour requested by setting
 **     SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
-**
-**   <li> <b>readonly_shm</b>: ^The readonly_shm parameter may be set to 
-**     either "1" or "0". Setting it to "1" indicates that if the database
-**     is in WAL mode and read-write access to the associated shared 
-**     memory region cannot be obtained, then an attempt should be made to open
-**     the shared-memory in read-only mode instead. If there exist one or
-**     more other database clients that have read-write connections to the
-**     database shared-memory, then a read-only shared-memory connection works 
-**     fine. However, if there exist no clients with read-write connections 
-**     to the shared-memory and the most recent such crashed or was interrupted
-**     by a power failure, then it is possible for a database client using a
-**     read-only connection to return incorrect data, incorrectly report 
-**     database corruption, or return an SQLITE_READONLY error. Or if the
-**     most recent read-write connection shut down cleanly, it may not be
-**     possible to open the shared-memory in read-only mode at all, and SQLite
-**     will return SQLITE_CANTOPEN.
 ** </ul>
 **
 ** ^Specifying an unknown parameter in the query component of a URI is not an
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 8b0aa855d8..fd86158e00 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2673,7 +2673,7 @@ void sqlite3AddColumnType(Parse*,Token*);
 void sqlite3AddDefaultValue(Parse*,ExprSpan*);
 void sqlite3AddCollateType(Parse*, Token*);
 void sqlite3EndTable(Parse*,Token*,Token*,Select*);
-int sqlite3ParseUri(const char*,const char*,unsigned int*,int*,
+int sqlite3ParseUri(const char*,const char*,unsigned int*,
                     sqlite3_vfs**,char**,char **);
 
 Bitvec *sqlite3BitvecCreate(u32);
diff --git a/src/wal.c b/src/wal.c
index 87d3fcc968..9f9e1115fa 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -406,14 +406,6 @@ struct WalCkptInfo {
 /*
 ** An open write-ahead log file is represented by an instance of the
 ** following object.
-**
-** The readOnlyShm variable is normally set to 0. If it is set to 1, then
-** the connection to shared-memory is read-only. This means it cannot
-** be written at all (even when read-locking the database). If it is set
-** to 2, then the shared-memory region is not yet open, but a read-only
-** connection is acceptable. In this case when the shared-memory is opened
-** (see function walIndexPage()), readOnlyShm is set to either 0 or 1 as
-** appropriate.
 */
 struct Wal {
   sqlite3_vfs *pVfs;         /* The VFS used to create pDbFd */
@@ -428,8 +420,7 @@ struct Wal {
   u8 exclusiveMode;          /* Non-zero if connection is in exclusive mode */
   u8 writeLock;              /* True if in a write transaction */
   u8 ckptLock;               /* True if holding a checkpoint lock */
-  u8 readOnly;               /* True if the WAL file is open read-only */
-  u8 readOnlyShm;            /* True if the SHM file is open read-only */
+  u8 readOnly;               /* WAL_RDWR, WAL_RDONLY, or WAL_SHM_RDONLY */
   WalIndexHdr hdr;           /* Wal-index header for current transaction */
   const char *zWalName;      /* Name of WAL file */
   u32 nCkpt;                 /* Checkpoint sequence counter in the wal-header */
@@ -445,6 +436,13 @@ struct Wal {
 #define WAL_EXCLUSIVE_MODE  1     
 #define WAL_HEAPMEMORY_MODE 2
 
+/*
+** Possible values for WAL.readOnly
+*/
+#define WAL_RDWR        0    /* Normal read/write connection */
+#define WAL_RDONLY      1    /* The WAL file is readonly */
+#define WAL_SHM_RDONLY  2    /* The SHM file is readonly */
+
 /*
 ** Each page of the wal-index mapping contains a hash-table made up of
 ** an array of HASHTABLE_NSLOT elements of the following type.
@@ -538,23 +536,15 @@ static int walIndexPage(Wal *pWal, int iPage, volatile u32 **ppPage){
       rc = sqlite3OsShmMap(pWal->pDbFd, iPage, WALINDEX_PGSZ, 
           pWal->writeLock, (void volatile **)&pWal->apWiData[iPage]
       );
-      if( rc==SQLITE_CANTOPEN && pWal->readOnlyShm>1 ){
-        assert( iPage==0 );
-        sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_READONLY_SHM, (void*)1);
-        rc = sqlite3OsShmMap(pWal->pDbFd, iPage, WALINDEX_PGSZ, 
-            pWal->writeLock, (void volatile **)&pWal->apWiData[iPage]
-        );
-        if( rc==SQLITE_OK ){
-          pWal->readOnly = pWal->readOnlyShm = 1;
-        }
-        sqlite3OsFileControl(pWal->pDbFd, SQLITE_FCNTL_READONLY_SHM, (void*)0);
+      if( rc==SQLITE_READONLY ){
+        pWal->readOnly |= WAL_SHM_RDONLY;
+        rc = SQLITE_OK;
       }
     }
   }
-  *ppPage = pWal->apWiData[iPage];
 
+  *ppPage = pWal->apWiData[iPage];
   assert( iPage==0 || *ppPage || rc!=SQLITE_OK );
-  if( pWal->readOnlyShm>1 ) pWal->readOnlyShm = 0;
   return rc;
 }
 
@@ -794,7 +784,6 @@ static void walUnlockShared(Wal *pWal, int lockIdx){
 }
 static int walLockExclusive(Wal *pWal, int lockIdx, int n){
   int rc;
-  assert( pWal->readOnlyShm==0 );
   if( pWal->exclusiveMode ) return SQLITE_OK;
   rc = sqlite3OsShmLock(pWal->pDbFd, lockIdx, n,
                         SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE);
@@ -804,7 +793,6 @@ static int walLockExclusive(Wal *pWal, int lockIdx, int n){
   return rc;
 }
 static void walUnlockExclusive(Wal *pWal, int lockIdx, int n){
-  assert( pWal->readOnlyShm==0 );
   if( pWal->exclusiveMode ) return;
   (void)sqlite3OsShmLock(pWal->pDbFd, lockIdx, n,
                          SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE);
@@ -1080,7 +1068,6 @@ static int walIndexRecover(Wal *pWal){
   assert( WAL_ALL_BUT_WRITE==WAL_WRITE_LOCK+1 );
   assert( WAL_CKPT_LOCK==WAL_ALL_BUT_WRITE );
   assert( pWal->writeLock );
-  assert( pWal->readOnlyShm==0 );
   iLock = WAL_ALL_BUT_WRITE + pWal->ckptLock;
   nLock = SQLITE_SHM_NLOCK - iLock;
   rc = walLockExclusive(pWal, iLock, nLock);
@@ -1300,7 +1287,7 @@ int sqlite3WalOpen(
   flags = (SQLITE_OPEN_READWRITE|SQLITE_OPEN_CREATE|SQLITE_OPEN_WAL);
   rc = sqlite3OsOpen(pVfs, zWalName, pRet->pWalFd, flags, &flags);
   if( rc==SQLITE_OK && flags&SQLITE_OPEN_READONLY ){
-    pRet->readOnly = 1;
+    pRet->readOnly = WAL_RDONLY;
   }
 
   if( rc!=SQLITE_OK ){
@@ -1929,7 +1916,6 @@ static int walIndexReadHdr(Wal *pWal, int *pChanged){
     return rc;
   };
   assert( page0 || pWal->writeLock==0 );
-  assert( pWal->readOnlyShm==0 || pWal->readOnlyShm==1 );
 
   /* If the first page of the wal-index has been mapped, try to read the
   ** wal-index header immediately, without holding any lock. This usually
@@ -1939,11 +1925,11 @@ static int walIndexReadHdr(Wal *pWal, int *pChanged){
   badHdr = (page0 ? walIndexTryHdr(pWal, pChanged) : 1);
 
   /* If the first attempt failed, it might have been due to a race
-  ** with a writer. So lock the WAL_WRITE_LOCK byte and try again.
+  ** with a writer.  So get a WRITE lock and try again.
   */
   assert( badHdr==0 || pWal->writeLock==0 );
   if( badHdr ){
-    if( pWal->readOnlyShm ){
+    if( pWal->readOnly & WAL_SHM_RDONLY ){
       if( SQLITE_OK==(rc = walLockShared(pWal, WAL_WRITE_LOCK)) ){
         walUnlockShared(pWal, WAL_WRITE_LOCK);
         rc = SQLITE_READONLY_RECOVERY;
@@ -2150,7 +2136,9 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
   }
   /* There was once an "if" here. The extra "{" is to preserve indentation. */
   {
-    if( pWal->readOnlyShm==0 && (mxReadMark < pWal->hdr.mxFrame || mxI==0) ){
+    if( (pWal->readOnly & WAL_SHM_RDONLY)==0
+     && (mxReadMark<pWal->hdr.mxFrame || mxI==0)
+    ){
       for(i=1; i<WAL_NREADER; i++){
         rc = walLockExclusive(pWal, WAL_READ_LOCK(i), 1);
         if( rc==SQLITE_OK ){
@@ -2165,7 +2153,6 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
     }
     if( mxI==0 ){
       assert( rc==SQLITE_BUSY );
-      assert( rc==SQLITE_BUSY || (pWal->readOnlyShm && rc==SQLITE_OK) );
       return rc==SQLITE_BUSY ? WAL_RETRY : SQLITE_READONLY_CANTLOCK;
     }
 
@@ -2221,18 +2208,13 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
 ** Pager layer will use this to know that is cache is stale and
 ** needs to be flushed.
 */
-int sqlite3WalBeginReadTransaction(Wal *pWal, int readOnlyShm, int *pChanged){
+int sqlite3WalBeginReadTransaction(Wal *pWal, int *pChanged){
   int rc;                         /* Return code */
   int cnt = 0;                    /* Number of TryBeginRead attempts */
 
-  if( pWal->nWiData==0 || pWal->apWiData[0]==0 ){
-    assert( readOnlyShm==0 || readOnlyShm==1 );
-    pWal->readOnlyShm = readOnlyShm*2;
-  }
   do{
     rc = walTryBeginRead(pWal, pChanged, 0, ++cnt);
   }while( rc==WAL_RETRY );
-  assert( rc || pWal->readOnlyShm==0 || (readOnlyShm && pWal->readOnlyShm==1) );
   testcase( (rc&0xff)==SQLITE_BUSY );
   testcase( (rc&0xff)==SQLITE_IOERR );
   testcase( rc==SQLITE_PROTOCOL );
@@ -2407,7 +2389,6 @@ int sqlite3WalBeginWriteTransaction(Wal *pWal){
   if( pWal->readOnly ){
     return SQLITE_READONLY;
   }
-  assert( pWal->readOnlyShm==0 );
 
   /* Only one writer allowed at a time.  Get the write lock.  Return
   ** SQLITE_BUSY if unable.
@@ -2814,11 +2795,8 @@ int sqlite3WalCheckpoint(
   assert( pWal->ckptLock==0 );
   assert( pWal->writeLock==0 );
 
+  if( pWal->readOnly ) return SQLITE_READONLY;
   WALTRACE(("WAL%p: checkpoint begins\n", pWal));
-  if( pWal->readOnlyShm ){
-    return SQLITE_READONLY;
-  }
-
   rc = walLockExclusive(pWal, WAL_CKPT_LOCK, 1);
   if( rc ){
     /* Usually this is SQLITE_BUSY meaning that another thread or process
diff --git a/src/wal.h b/src/wal.h
index df09beffe7..a62b23bbdc 100644
--- a/src/wal.h
+++ b/src/wal.h
@@ -23,7 +23,7 @@
 # define sqlite3WalOpen(x,y,z)                   0
 # define sqlite3WalLimit(x,y)
 # define sqlite3WalClose(w,x,y,z)                0
-# define sqlite3WalBeginReadTransaction(x,y,z)   0
+# define sqlite3WalBeginReadTransaction(y,z)     0
 # define sqlite3WalEndReadTransaction(z)
 # define sqlite3WalRead(v,w,x,y,z)               0
 # define sqlite3WalDbsize(y)                     0
@@ -60,7 +60,7 @@ void sqlite3WalLimit(Wal*, i64);
 ** write to or checkpoint the WAL.  sqlite3WalCloseSnapshot() closes the
 ** transaction and releases the lock.
 */
-int sqlite3WalBeginReadTransaction(Wal *pWal, int, int *);
+int sqlite3WalBeginReadTransaction(Wal *pWal, int *);
 void sqlite3WalEndReadTransaction(Wal *pWal);
 
 /* Read a page from the write-ahead log, if it is present. */

From fd019ef7ceaf17d41a47c3be1ef7309deb9be7eb Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Wed, 1 Jun 2011 20:13:36 +0000
Subject: [PATCH 17/30] Make use of the sqlite3GetBoolean() interface for more
 robust processing of the readonly_shm query parameter inside of unixShmMap().

FossilOrigin-Name: 1f930d7e04cd4a5ff3d91a0e9f1b62114f1cebd2
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/os_unix.c |  2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/manifest b/manifest
index 8b6e11236e..b9fd02df11 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Simplify\sthe\swal-readonly\sbranch\sso\sthat\sit\sdoes\snot\srequire\schanges\sto\nanything\sother\sthan\sos_unix.c\sand\swal.c\sand\sa\scouple\sof\snew\serror\scodes.
-D 2011-06-01T20:01:49.650
+C Make\suse\sof\sthe\ssqlite3GetBoolean()\sinterface\sfor\smore\srobust\sprocessing\nof\sthe\sreadonly_shm\squery\sparameter\sinside\sof\sunixShmMap().
+D 2011-06-01T20:13:36.269
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -163,7 +163,7 @@ F src/os.c 22ac61d06e72a0dac900400147333b07b13d8e1d
 F src/os.h 9dbed8c2b9c1f2f2ebabc09e49829d4777c26bf9
 F src/os_common.h a8f95b81eca8a1ab8593d23e94f8a35f35d4078f
 F src/os_os2.c 4a75888ba3dfc820ad5e8177025972d74d7f2440
-F src/os_unix.c a59c0718021934157f235468788c793cbc0d53de
+F src/os_unix.c fd4e9588ff0ce09720721ce739ab2682202875ae
 F src/os_win.c 218b899469e570d46eb8147c2383075f7c026230
 F src/pager.c 120550e7ef01dafaa2cbb4a0528c0d87c8f12b41
 F src/pager.h 3f8c783de1d4706b40b1ac15b64f5f896bcc78d1
@@ -939,7 +939,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 0b63b71357a65e26ecd3f3bb34a5f14feee322f4
-R 20a045d8e6470f5f17b67b2f15ff8859
+P d6b4709de4d1f8af001f58938247f00a652a616e
+R fdd310892b7cea51b352170f4a152593
 U drh
-Z f7b3b70c555e3fb5f3360ed8e60c2877
+Z cc8ff93f2b92f997226013b652879169
diff --git a/manifest.uuid b/manifest.uuid
index 6f393899aa..203442f1d4 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-d6b4709de4d1f8af001f58938247f00a652a616e
\ No newline at end of file
+1f930d7e04cd4a5ff3d91a0e9f1b62114f1cebd2
\ No newline at end of file
diff --git a/src/os_unix.c b/src/os_unix.c
index e6d1774a49..5860ae71a9 100644
--- a/src/os_unix.c
+++ b/src/os_unix.c
@@ -3787,7 +3787,7 @@ static int unixOpenSharedMemory(unixFile *pDbFd){
       if( pShmNode->h<0 ){
         const char *zRO;
         zRO = sqlite3_uri_parameter(pDbFd->zPath, "readonly_shm");
-        if( zRO && (zRO[0]!='0' || zRO[1]!=0) ){
+        if( zRO && sqlite3GetBoolean(zRO) ){
           pShmNode->h = robust_open(zShmFilename, O_RDONLY,
                                     (sStat.st_mode & 0777));
           pShmNode->isReadonly = 1;

From 070d422d31cec08996630f03622afed9b1d2407a Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Thu, 2 Jun 2011 15:48:51 +0000
Subject: [PATCH 18/30] Add a missing check for out-of-memory in the lemon code
 generator.

FossilOrigin-Name: efb20b9da6c7cb310a449cc818eaccd3d5bb4ab3
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 tool/lemon.c  |  6 +++++-
 3 files changed, 12 insertions(+), 8 deletions(-)

diff --git a/manifest b/manifest
index f2e67cf931..355ba1eb5b 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Merge\sthe\sread-only\sshared\smemory\sbranch\sinto\strunk.\s\sAfter\sthis\smerge,\san\nunprivileged\sprocess\scan\sopen\sWAL-mode\sdatabases\sowned\sby\sanother\suser\sas\nlong\sas\sa\sdatabase\sconnection\swith\swrite\spermission\sexists\son\sthe\sdatabase\nfile\sand\sif\sthe\sreadonly_shm=1\sURI\squery\sparameter\sis\ssupplied.
-D 2011-06-02T13:04:33.467
+C Add\sa\smissing\scheck\sfor\sout-of-memory\sin\sthe\slemon\scode\sgenerator.
+D 2011-06-02T15:48:51.684
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -909,7 +909,7 @@ F tool/fragck.tcl 5265a95126abcf6ab357f7efa544787e5963f439
 F tool/genfkey.README cf68fddd4643bbe3ff8e31b8b6d8b0a1b85e20f4
 F tool/genfkey.test 4196a8928b78f51d54ef58e99e99401ab2f0a7e5
 F tool/getlock.c f4c39b651370156cae979501a7b156bdba50e7ce
-F tool/lemon.c dfd81a51b6e27e469ba21d01a75ddf092d429027
+F tool/lemon.c 2f182cf58a44a29107ad0027e4e696c79cbb9ad6
 F tool/lempar.c 01ca97f87610d1dac6d8cd96ab109ab1130e76dc
 F tool/mkkeywordhash.c d2e6b4a5965e23afb80fbe74bb54648cd371f309
 F tool/mkopts.tcl 66ac10d240cc6e86abd37dc908d50382f84ff46e
@@ -939,7 +939,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P e704e8690ae35decc9769a45cf8d519ccad8b79d 1f930d7e04cd4a5ff3d91a0e9f1b62114f1cebd2
-R fdd310892b7cea51b352170f4a152593
+P 19084a6641f77a62110b04ea50e298fe132ea784
+R 35b0b86c3f244adcf3711ae5d8007435
 U drh
-Z c21bc600f09ce2bc60c48c66dd9bd252
+Z df920ad923d5c14dce2ff7d7b1f2c419
diff --git a/manifest.uuid b/manifest.uuid
index 2a33332676..2ce7958fe9 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-19084a6641f77a62110b04ea50e298fe132ea784
\ No newline at end of file
+efb20b9da6c7cb310a449cc818eaccd3d5bb4ab3
\ No newline at end of file
diff --git a/tool/lemon.c b/tool/lemon.c
index 898022e28c..0a50524854 100644
--- a/tool/lemon.c
+++ b/tool/lemon.c
@@ -3434,6 +3434,10 @@ void print_stack_union(
   /* Allocate and initialize types[] and allocate stddt[] */
   arraysize = lemp->nsymbol * 2;
   types = (char**)calloc( arraysize, sizeof(char*) );
+  if( types==0 ){
+    fprintf(stderr,"Out of memory.\n");
+    exit(1);
+  }
   for(i=0; i<arraysize; i++) types[i] = 0;
   maxdtlength = 0;
   if( lemp->vartype ){
@@ -3447,7 +3451,7 @@ void print_stack_union(
     if( len>maxdtlength ) maxdtlength = len;
   }
   stddt = (char*)malloc( maxdtlength*2 + 1 );
-  if( types==0 || stddt==0 ){
+  if( stddt==0 ){
     fprintf(stderr,"Out of memory.\n");
     exit(1);
   }

From 5bf3934652568cdef29ca24ab9585004e11d0ce3 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Thu, 2 Jun 2011 17:24:49 +0000
Subject: [PATCH 19/30] Fix a faulty assert() in the WAL-mode logic for
 read-only shared memory.

FossilOrigin-Name: a13cfe616284f4ee86f0406e7b8fe8f9ba6e6990
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/wal.c     |  2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/manifest b/manifest
index 355ba1eb5b..f04e836195 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\sa\smissing\scheck\sfor\sout-of-memory\sin\sthe\slemon\scode\sgenerator.
-D 2011-06-02T15:48:51.684
+C Fix\sa\sfaulty\sassert()\sin\sthe\sWAL-mode\slogic\sfor\sread-only\sshared\smemory.
+D 2011-06-02T17:24:49.997
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -245,7 +245,7 @@ F src/vdbeblob.c f024f0bf420f36b070143c32b15cc7287341ffd3
 F src/vdbemem.c 0498796b6ffbe45e32960d6a1f5adfb6e419883b
 F src/vdbetrace.c 5d0dc3d5fd54878cc8d6d28eb41deb8d5885b114
 F src/vtab.c 9ba8c7fdb7d39260c033a402f6032d3e7bc5d336
-F src/wal.c fd63d07233203dd3bd29cbe1ae5c8bb2c34e08fc
+F src/wal.c 0c70ad7b1cac6005fa5e2cbefd23ee05e391c290
 F src/wal.h 66b40bd91bc29a5be1c88ddd1f5ade8f3f48728a
 F src/walker.c 3112bb3afe1d85dc52317cb1d752055e9a781f8f
 F src/where.c 55403ce19c506be6a321c7f129aff693d6103db5
@@ -939,7 +939,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 19084a6641f77a62110b04ea50e298fe132ea784
-R 35b0b86c3f244adcf3711ae5d8007435
+P efb20b9da6c7cb310a449cc818eaccd3d5bb4ab3
+R 7af7e431287e95dc91be1106acfd740b
 U drh
-Z df920ad923d5c14dce2ff7d7b1f2c419
+Z e77c10de1c037b59f0516366918c7ba0
diff --git a/manifest.uuid b/manifest.uuid
index 2ce7958fe9..b636e3ed7d 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-efb20b9da6c7cb310a449cc818eaccd3d5bb4ab3
\ No newline at end of file
+a13cfe616284f4ee86f0406e7b8fe8f9ba6e6990
\ No newline at end of file
diff --git a/src/wal.c b/src/wal.c
index 9f9e1115fa..b9a03dff23 100644
--- a/src/wal.c
+++ b/src/wal.c
@@ -2152,7 +2152,7 @@ static int walTryBeginRead(Wal *pWal, int *pChanged, int useWal, int cnt){
       }
     }
     if( mxI==0 ){
-      assert( rc==SQLITE_BUSY );
+      assert( rc==SQLITE_BUSY || (pWal->readOnly & WAL_SHM_RDONLY)!=0 );
       return rc==SQLITE_BUSY ? WAL_RETRY : SQLITE_READONLY_CANTLOCK;
     }
 

From be07ec582e358da8a7864d882a20596d6cb69dda Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Fri, 3 Jun 2011 12:15:26 +0000
Subject: [PATCH 20/30] Fix an #ifdef of SQLITE_OMIT_VIRTUALTABLE that had an
 extra "_" character.

FossilOrigin-Name: 93e0be2bbf16d66d97ea7344187139d254b11cc3
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/vdbe.c    |  2 +-
 3 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/manifest b/manifest
index f04e836195..62c45edfca 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sa\sfaulty\sassert()\sin\sthe\sWAL-mode\slogic\sfor\sread-only\sshared\smemory.
-D 2011-06-02T17:24:49.997
+C Fix\san\s#ifdef\sof\sSQLITE_OMIT_VIRTUALTABLE\sthat\shad\san\sextra\s"_"\scharacter.
+D 2011-06-03T12:15:26.459
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -236,7 +236,7 @@ F src/update.c 5bcb56e5c7380a2eecb0e71891dbd4ad7437748f
 F src/utf.c d83650c3ea08f7407bd9d0839d9885241c209c60
 F src/util.c 0f33bbbdfcc4a2d8cf20c3b2a16ffc3b57c58a70
 F src/vacuum.c 05513dca036a1e7848fe18d5ed1265ac0b32365e
-F src/vdbe.c 2ec37637fa70ab0c694d8327ee5dcedbc0621524
+F src/vdbe.c edfa3827d7a6fac2425bc10c0eb6e54342d2fa56
 F src/vdbe.h d9c6123384189dc37d27beac1bf44688aa75b6cb
 F src/vdbeInt.h ad84226cc0adcb1185c22b70696b235a1678bb45
 F src/vdbeapi.c 0eeadc75e44a30efd996d6af6e7c5a2488e35be8
@@ -939,7 +939,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P efb20b9da6c7cb310a449cc818eaccd3d5bb4ab3
-R 7af7e431287e95dc91be1106acfd740b
+P a13cfe616284f4ee86f0406e7b8fe8f9ba6e6990
+R 560ca19206a2de258e4ac41eb28208c5
 U drh
-Z e77c10de1c037b59f0516366918c7ba0
+Z 105c7f13fbfb0b81256f08e0207c0eef
diff --git a/manifest.uuid b/manifest.uuid
index b636e3ed7d..8cec759819 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-a13cfe616284f4ee86f0406e7b8fe8f9ba6e6990
\ No newline at end of file
+93e0be2bbf16d66d97ea7344187139d254b11cc3
\ No newline at end of file
diff --git a/src/vdbe.c b/src/vdbe.c
index 439fe72540..97a0a6a555 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -2585,7 +2585,7 @@ case OP_Savepoint: {
     }else{
       nName = sqlite3Strlen30(zName);
 
-#ifndef SQLITE_OMIT_VIRTUAL_TABLE
+#ifndef SQLITE_OMIT_VIRTUALTABLE
       /* This call is Ok even if this savepoint is actually a transaction
       ** savepoint (and therefore should not prompt xSavepoint()) callbacks.
       ** If this is a transaction savepoint being opened, it is guaranteed

From c7dc9bf88ed33e1676dd8e53b57eb330f8bf78fa Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Fri, 3 Jun 2011 13:02:57 +0000
Subject: [PATCH 21/30] Fix the build when using SQLITE_OMIT_PRAGMA.

FossilOrigin-Name: 051f4635bf1e9618b108c4177b8ecc5762ed08e7
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/pragma.c  | 10 ++++++----
 3 files changed, 13 insertions(+), 11 deletions(-)

diff --git a/manifest b/manifest
index 62c45edfca..e99630aa85 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\san\s#ifdef\sof\sSQLITE_OMIT_VIRTUALTABLE\sthat\shad\san\sextra\s"_"\scharacter.
-D 2011-06-03T12:15:26.459
+C Fix\sthe\sbuild\swhen\susing\sSQLITE_OMIT_PRAGMA.
+D 2011-06-03T13:02:57.441
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -171,7 +171,7 @@ F src/parse.y 12b7ebd61ea54f0e1b1083ff69cc2c8ce9353d58
 F src/pcache.c 49e718c095810c6b3334e3a6d89970aceaddefce
 F src/pcache.h c683390d50f856d4cd8e24342ae62027d1bb6050
 F src/pcache1.c d548e31beafa792d1994b663a29a5303569efc4e
-F src/pragma.c 9e778decc3ee9bcaf88904b4a3b0a4360aaf0eab
+F src/pragma.c ebcd20f1e654f5cb3aeef864ed69c4697719fbaa
 F src/prepare.c e64261559a3187698a3e7e6c8b001a4f4f98dab4
 F src/printf.c 585a36b6a963df832cfb69505afa3a34ed5ef8a1
 F src/random.c cd4a67b3953b88019f8cd4ccd81394a8ddfaba50
@@ -939,7 +939,7 @@ F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P a13cfe616284f4ee86f0406e7b8fe8f9ba6e6990
-R 560ca19206a2de258e4ac41eb28208c5
+P 93e0be2bbf16d66d97ea7344187139d254b11cc3
+R 4ed98f1ed7ddc5d80458937702f664db
 U drh
-Z 105c7f13fbfb0b81256f08e0207c0eef
+Z 234b0b60ed4ca4872a72109fff862187
diff --git a/manifest.uuid b/manifest.uuid
index 8cec759819..ae169702be 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-93e0be2bbf16d66d97ea7344187139d254b11cc3
\ No newline at end of file
+051f4635bf1e9618b108c4177b8ecc5762ed08e7
\ No newline at end of file
diff --git a/src/pragma.c b/src/pragma.c
index 799805c40b..cd2aab223c 100644
--- a/src/pragma.c
+++ b/src/pragma.c
@@ -13,10 +13,6 @@
 */
 #include "sqliteInt.h"
 
-/* Ignore this whole file if pragmas are disabled
-*/
-#if !defined(SQLITE_OMIT_PRAGMA)
-
 /*
 ** Interpret the given string as a safety level.  Return 0 for OFF,
 ** 1 for ON or NORMAL and 2 for FULL.  Return 1 for an empty or 
@@ -53,6 +49,12 @@ u8 sqlite3GetBoolean(const char *z){
   return getSafetyLevel(z)&1;
 }
 
+/* The sqlite3GetBoolean() function is used by other modules but the
+** remainder of this file is specific to PRAGMA processing.  So omit
+** the rest of the file if PRAGMAs are omitted from the build.
+*/
+#if !defined(SQLITE_OMIT_PRAGMA)
+
 /*
 ** Interpret the given string as a locking mode value.
 */

From 3043ac70c44024b0f0cab143392805dcf02e095f Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Fri, 3 Jun 2011 13:06:50 +0000
Subject: [PATCH 22/30] Add shell scripts used for testing compiler warnings
 (tool/warnings.sh), for verifying that the library exports the correct
 symbols (tool/symbols.sh), and to demonstrate building a full-featured
 command-line shell (tool/build-shell.sh).

FossilOrigin-Name: 3aca9a92c8b29bb43f65f93593ba4defd65139dc
---
 manifest            | 13 ++++++++-----
 manifest.uuid       |  2 +-
 tool/build-shell.sh | 21 +++++++++++++++++++++
 tool/symbols.sh     | 34 ++++++++++++++++++++++++++++++++++
 tool/warnings.sh    | 14 ++++++++++++++
 5 files changed, 78 insertions(+), 6 deletions(-)
 create mode 100644 tool/build-shell.sh
 create mode 100644 tool/symbols.sh
 create mode 100644 tool/warnings.sh

diff --git a/manifest b/manifest
index e99630aa85..c7ac33de9e 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Fix\sthe\sbuild\swhen\susing\sSQLITE_OMIT_PRAGMA.
-D 2011-06-03T13:02:57.441
+C Add\sshell\sscripts\sused\sfor\stesting\scompiler\swarnings\s(tool/warnings.sh),\nfor\sverifying\sthat\sthe\slibrary\sexports\sthe\scorrect\ssymbols\s(tool/symbols.sh),\nand\sto\sdemonstrate\sbuilding\sa\sfull-featured\scommand-line\sshell\n(tool/build-shell.sh).
+D 2011-06-03T13:06:50.043
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -904,6 +904,7 @@ F test/whereA.test 24c234263c8fe358f079d5e57d884fb569d2da0a
 F test/whereB.test 0def95db3bdec220a731c7e4bec5930327c1d8c5
 F test/wherelimit.test 5e9fd41e79bb2b2d588ed999d641d9c965619b31
 F test/zeroblob.test caaecfb4f908f7bc086ed238668049f96774d688
+F tool/build-shell.sh 12aa4391073a777fcb6dcc490b219a018ae98bac
 F tool/diffdb.c 7524b1b5df217c20cd0431f6789851a4e0cb191b
 F tool/fragck.tcl 5265a95126abcf6ab357f7efa544787e5963f439
 F tool/genfkey.README cf68fddd4643bbe3ff8e31b8b6d8b0a1b85e20f4
@@ -938,8 +939,10 @@ F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
 F tool/speedtest8.c 2902c46588c40b55661e471d7a86e4dd71a18224
 F tool/speedtest8inst1.c 293327bc76823f473684d589a8160bde1f52c14e
 F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
+F tool/symbols.sh bc2a3709940d47c8ac8e0a1fdf17ec801f015a00
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
-P 93e0be2bbf16d66d97ea7344187139d254b11cc3
-R 4ed98f1ed7ddc5d80458937702f664db
+F tool/warnings.sh 347d974d143cf132f953b565fbc03026f19fcb4d
+P 051f4635bf1e9618b108c4177b8ecc5762ed08e7
+R 9da6c706bda9f5ba334ec4313d0142ea
 U drh
-Z 234b0b60ed4ca4872a72109fff862187
+Z a1ce6be566aa33f6b6cc12b210f2a7c9
diff --git a/manifest.uuid b/manifest.uuid
index ae169702be..face1e362d 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-051f4635bf1e9618b108c4177b8ecc5762ed08e7
\ No newline at end of file
+3aca9a92c8b29bb43f65f93593ba4defd65139dc
\ No newline at end of file
diff --git a/tool/build-shell.sh b/tool/build-shell.sh
new file mode 100644
index 0000000000..54e8308095
--- /dev/null
+++ b/tool/build-shell.sh
@@ -0,0 +1,21 @@
+#!/bin/sh
+#
+# This script demonstrates how to do a full-featured build of the sqlite3
+# command-line shell on Linux.
+#
+# SQLite source code should be in a sibling directory named "sqlite".  For
+# example, put SQLite sources in ~/sqlite/sqlite and run this script from
+# ~/sqlite/bld.  There should be an appropriate Makefile in the current
+# directory as well.
+#
+make sqlite3.c
+gcc -o sqlite3 -g -Os -I. \
+   -DSQLITE_THREADSAFE=0 \
+   -DSQLITE_ENABLE_VFSTRACE \
+   -DSQLITE_ENABLE_STAT2 \
+   -DSQLITE_ENABLE_FTS3 \
+   -DSQLITE_ENABLE_RTREE \
+   -DHAVE_READLINE \
+   -DHAVE_USLEEP=1 \
+   ../sqlite/src/shell.c ../sqlite/src/test_vfstrace.c \
+   sqlite3.c -ldl -lreadline -lncurses
diff --git a/tool/symbols.sh b/tool/symbols.sh
new file mode 100644
index 0000000000..8aec00569a
--- /dev/null
+++ b/tool/symbols.sh
@@ -0,0 +1,34 @@
+#!/bin/sh
+#
+# Run this script in a directory that contains a valid SQLite makefile in
+# order to verify that unintentionally exported symbols.
+#
+make sqlite3.c
+
+echo '****** Exported symbols from a build including RTREE, FTS4 & ICU ******'
+gcc -c -DSQLITE_ENABLE_FTS3 -DSQLITE_ENABLE_RTREE \
+  -DSQLITE_ENABLE_MEMORY_MANAGEMENT -DSQLITE_ENABLE_STAT2 \
+  -DSQLITE_ENABLE_MEMSYS5 -DSQLITE_ENABLE_UNLOCK_NOTIFY \
+  -DSQLITE_ENABLE_COLUMN_METADATA -DSQLITE_ENABLE_ATOMIC_WRITE \
+  -DSQLITE_ENABLE_ICU \
+  sqlite3.c
+nm sqlite3.o | grep ' T ' | sort -k 3
+
+echo '****** Surplus symbols from a build including RTREE, FTS4 & ICU ******'
+nm sqlite3.o | grep ' T ' | grep -v ' sqlite3_'
+
+echo '****** Dependencies of the core. No extensions. No OS interface *******'
+gcc -c -DSQLITE_ENABLE_MEMORY_MANAGEMENT -DSQLITE_ENABLE_STAT2 \
+  -DSQLITE_ENABLE_MEMSYS5 -DSQLITE_ENABLE_UNLOCK_NOTIFY \
+  -DSQLITE_ENABLE_COLUMN_METADATA -DSQLITE_ENABLE_ATOMIC_WRITE \
+  -DSQLITE_OS_OTHER -DSQLITE_THREADSAFE=0 \
+  sqlite3.c
+nm sqlite3.o | grep ' U ' | sort -k 3
+
+echo '****** Dependencies including RTREE & FTS4 *******'
+gcc -c -DSQLITE_ENABLE_FTS3 -DSQLITE_ENABLE_RTREE \
+  -DSQLITE_ENABLE_MEMORY_MANAGEMENT -DSQLITE_ENABLE_STAT2 \
+  -DSQLITE_ENABLE_MEMSYS5 -DSQLITE_ENABLE_UNLOCK_NOTIFY \
+  -DSQLITE_ENABLE_COLUMN_METADATA -DSQLITE_ENABLE_ATOMIC_WRITE \
+  sqlite3.c
+nm sqlite3.o | grep ' U ' | sort -k 3
diff --git a/tool/warnings.sh b/tool/warnings.sh
new file mode 100644
index 0000000000..e1fa2b2d91
--- /dev/null
+++ b/tool/warnings.sh
@@ -0,0 +1,14 @@
+#/bin/sh
+#
+# Run this script in a directory with a working makefile to check for 
+# compiler warnings in SQLite.
+#
+make sqlite3.c
+echo '********** No optimizations.  Includes FTS4 and RTREE *********'
+gcc -c -Wshadow -Wall -Wextra -pedantic-errors -Wno-long-long -std=c89 \
+      -ansi -DHAVE_STDINT_H -DSQLITE_ENABLE_FTS4 -DSQLITE_ENABLE_RTREE \
+      sqlite3.c
+echo '********** Optimized -O3.  Includes FTS4 and RTREE *********'
+gcc -O3 -c -Wshadow -Wall -Wextra -pedantic-errors -Wno-long-long -std=c89 \
+      -ansi -DHAVE_STDINT_H -DSQLITE_ENABLE_FTS4 -DSQLITE_ENABLE_RTREE \
+      sqlite3.c

From 9fd301bb6ac5e9d7e017fff079d9034716ae1a09 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Fri, 3 Jun 2011 13:28:22 +0000
Subject: [PATCH 23/30] Include more detailed version information in the
 command-line shell output.

FossilOrigin-Name: 049c3c42fdefea8de7ec7008871963e37ce2d7bc
---
 manifest         | 14 +++++++-------
 manifest.uuid    |  2 +-
 src/shell.c      | 11 ++++++++---
 tool/shell1.test |  5 +++--
 4 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/manifest b/manifest
index c7ac33de9e..bcc31ebfb3 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Add\sshell\sscripts\sused\sfor\stesting\scompiler\swarnings\s(tool/warnings.sh),\nfor\sverifying\sthat\sthe\slibrary\sexports\sthe\scorrect\ssymbols\s(tool/symbols.sh),\nand\sto\sdemonstrate\sbuilding\sa\sfull-featured\scommand-line\sshell\n(tool/build-shell.sh).
-D 2011-06-03T13:06:50.043
+C Include\smore\sdetailed\sversion\sinformation\sin\sthe\scommand-line\sshell\soutput.
+D 2011-06-03T13:28:22.119
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -178,7 +178,7 @@ F src/random.c cd4a67b3953b88019f8cd4ccd81394a8ddfaba50
 F src/resolve.c 1c0f32b64f8e3f555fe1f732f9d6f501a7f05706
 F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
 F src/select.c d9d440809025a58547e39f4f268c2a296bfb56ff
-F src/shell.c decd04236a7ef26be5ef46d4ea963044bfad9a48
+F src/shell.c 0e0173b3e79d956368013e759f084caa7995ecb1
 F src/sqlite.h.in 2f51e4f58b2b4626fcbd9938580e730cb5fb4985
 F src/sqlite3ext.h c90bd5507099f62043832d73f6425d8d5c5da754
 F src/sqliteInt.h 6e58c558c57c8f44011736d5fa5295eb3130f9de
@@ -922,7 +922,7 @@ F tool/omittest.tcl b1dd290c1596e0f31fd335160a74ec5dfea3df4a
 F tool/opcodeDoc.awk b3a2a3d5d3075b8bd90b7afe24283efdd586659c
 F tool/restore_jrnl.tcl 6957a34f8f1f0f8285e07536225ec3b292a9024a
 F tool/rollback-test.c 9fc98427d1e23e84429d7e6d07d9094fbdec65a5
-F tool/shell1.test 5542ecdc952f91121a835ed817e6feaf8988b333
+F tool/shell1.test 20dfe7099cf2afe37aecd69afb7678d14f7a0abf
 F tool/shell2.test 5dc76b8005b465f420fed8241621da7513060ff3
 F tool/shell3.test 4fad469e8003938426355afdf34155f08c587836
 F tool/shell4.test 35f9c3d452b4e76d5013c63e1fd07478a62f14ce
@@ -942,7 +942,7 @@ F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/symbols.sh bc2a3709940d47c8ac8e0a1fdf17ec801f015a00
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings.sh 347d974d143cf132f953b565fbc03026f19fcb4d
-P 051f4635bf1e9618b108c4177b8ecc5762ed08e7
-R 9da6c706bda9f5ba334ec4313d0142ea
+P 3aca9a92c8b29bb43f65f93593ba4defd65139dc
+R 1eb21a9d7ed9685f625d6c1573544e8b
 U drh
-Z a1ce6be566aa33f6b6cc12b210f2a7c9
+Z 70d86fceaffca6cead41b36e31773fcc
diff --git a/manifest.uuid b/manifest.uuid
index face1e362d..13a02e0d29 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-3aca9a92c8b29bb43f65f93593ba4defd65139dc
\ No newline at end of file
+049c3c42fdefea8de7ec7008871963e37ce2d7bc
\ No newline at end of file
diff --git a/src/shell.c b/src/shell.c
index 8e9870a5a8..a54c922e87 100644
--- a/src/shell.c
+++ b/src/shell.c
@@ -2302,6 +2302,11 @@ static int do_meta_command(char *zLine, struct callback_data *p){
     enableTimer = booleanValue(azArg[1]);
   }else
   
+  if( c=='v' && strncmp(azArg[0], "version", n)==0 ){
+    printf("SQLite %s %s\n",
+        sqlite3_libversion(), sqlite3_sourceid());
+  }else
+
   if( c=='w' && strncmp(azArg[0], "width", n)==0 && nArg>1 ){
     int j;
     assert( nArg<=ArraySize(azArg) );
@@ -2836,7 +2841,7 @@ int main(int argc, char **argv){
     }else if( strcmp(z,"-bail")==0 ){
       bail_on_error = 1;
     }else if( strcmp(z,"-version")==0 ){
-      printf("%s\n", sqlite3_libversion());
+      printf("%s %s\n", sqlite3_libversion(), sqlite3_sourceid());
       return 0;
     }else if( strcmp(z,"-interactive")==0 ){
       stdin_is_interactive = 1;
@@ -2881,10 +2886,10 @@ int main(int argc, char **argv){
       char *zHistory = 0;
       int nHistory;
       printf(
-        "SQLite version %s\n"
+        "SQLite version %s %.19s\n"
         "Enter \".help\" for instructions\n"
         "Enter SQL statements terminated with a \";\"\n",
-        sqlite3_libversion()
+        sqlite3_libversion(), sqlite3_sourceid()
       );
       zHome = find_home_dir();
       if( zHome ){
diff --git a/tool/shell1.test b/tool/shell1.test
index 068f8ea25c..9dd9df5555 100644
--- a/tool/shell1.test
+++ b/tool/shell1.test
@@ -199,8 +199,9 @@ do_test shell1-1.15.3 {
 
 # -version             show SQLite version
 do_test shell1-1.16.1 {
-  catchcmd "-version test.db" "" 
-} {0 3.7.7}
+  set x [catchcmd "-version test.db" ""]
+  regexp {0 \{3.\d.\d+ 20\d\d-[01]\d-\d\d \d\d:\d\d:\d\d [0-9a-f]+\}} $x 
+} 1
 
 #----------------------------------------------------------------------------
 # Test cases shell1-2.*: Basic "dot" command token parsing.

From 45caededba6bd24dcbd31c5db1bb0d423fb8be9e Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Fri, 3 Jun 2011 14:19:10 +0000
Subject: [PATCH 24/30] Hush some harmless compiler warnings in the URI parsing
 logic.

FossilOrigin-Name: 0206bc6f87bb9393218a380fc5b18039d334a8d8
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/main.c    |  6 +++---
 3 files changed, 10 insertions(+), 10 deletions(-)

diff --git a/manifest b/manifest
index bcc31ebfb3..1099d5534a 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Include\smore\sdetailed\sversion\sinformation\sin\sthe\scommand-line\sshell\soutput.
-D 2011-06-03T13:28:22.119
+C Hush\ssome\sharmless\scompiler\swarnings\sin\sthe\sURI\sparsing\slogic.
+D 2011-06-03T14:19:10.707
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -144,7 +144,7 @@ F src/journal.c 552839e54d1bf76fb8f7abe51868b66acacf6a0e
 F src/legacy.c a199d7683d60cef73089e892409113e69c23a99f
 F src/lempar.c 7f026423f4d71d989e719a743f98a1cbd4e6d99e
 F src/loadext.c 3ae0d52da013a6326310655be6473fd472347b85
-F src/main.c 059daeed5876b3604f0192f838faf5f4db138901
+F src/main.c d67ea48933e4d63abba00578224a3319e6fbcbe1
 F src/malloc.c 591aedb20ae40813f1045f2ef253438a334775d9
 F src/mem0.c 6a55ebe57c46ca1a7d98da93aaa07f99f1059645
 F src/mem1.c 00bd8265c81abb665c48fea1e0c234eb3b922206
@@ -942,7 +942,7 @@ F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/symbols.sh bc2a3709940d47c8ac8e0a1fdf17ec801f015a00
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings.sh 347d974d143cf132f953b565fbc03026f19fcb4d
-P 3aca9a92c8b29bb43f65f93593ba4defd65139dc
-R 1eb21a9d7ed9685f625d6c1573544e8b
+P 049c3c42fdefea8de7ec7008871963e37ce2d7bc
+R 06582f4582a8157c228d4b288a346794
 U drh
-Z 70d86fceaffca6cead41b36e31773fcc
+Z 0eb02a6eb0f61a953a539b049b2322b5
diff --git a/manifest.uuid b/manifest.uuid
index 13a02e0d29..a5c8a3d8b3 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-049c3c42fdefea8de7ec7008871963e37ce2d7bc
\ No newline at end of file
+0206bc6f87bb9393218a380fc5b18039d334a8d8
\ No newline at end of file
diff --git a/src/main.c b/src/main.c
index c99d396546..d3386eb0cd 100644
--- a/src/main.c
+++ b/src/main.c
@@ -1938,9 +1938,9 @@ int sqlite3ParseUri(
           const char *z;
           int mode;
         } *aMode = 0;
-        char *zModeType;
-        int mask;
-        int limit;
+        char *zModeType = 0;
+        int mask = 0;
+        int limit = 0;
 
         if( nOpt==5 && memcmp("cache", zOpt, 5)==0 ){
           static struct OpenMode aCacheMode[] = {

From 68f2a57698780de49312cdb0f11732c521955d60 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Fri, 3 Jun 2011 17:50:49 +0000
Subject: [PATCH 25/30] Factor an "if" out of a loop in balance_nonroot() for
 about a 1% performance increase.

FossilOrigin-Name: 1bd72d0c616e20fdb395c72ecd96579090ae26cb
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/btree.c   | 26 ++++++++++++++++++++------
 3 files changed, 27 insertions(+), 13 deletions(-)

diff --git a/manifest b/manifest
index 1099d5534a..b636720757 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Hush\ssome\sharmless\scompiler\swarnings\sin\sthe\sURI\sparsing\slogic.
-D 2011-06-03T14:19:10.707
+C Factor\san\s"if"\sout\sof\sa\sloop\sin\sbalance_nonroot()\sfor\sabout\sa\s1%\sperformance\nincrease.
+D 2011-06-03T17:50:49.782
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -122,7 +122,7 @@ F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
 F src/backup.c 986c15232757f2873dff35ee3b35cbf935fc573c
 F src/bitvec.c af50f1c8c0ff54d6bdb7a80e2fceca5a93670bef
 F src/btmutex.c 976f45a12e37293e32cae0281b15a21d48a8aaa7
-F src/btree.c 0d3b39dcb79565c053e35fc12713f12d8a74d6a9
+F src/btree.c 12aa3b71359c888984223cb2bcf691cf2d7753ae
 F src/btree.h f5d775cd6cfc7ac32a2535b70e8d2af48ef5f2ce
 F src/btreeInt.h 67978c014fa4f7cc874032dd3aacadd8db656bc3
 F src/build.c c10ab9e2c77ade99dee23554787f8acfc0c231fc
@@ -942,7 +942,7 @@ F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/symbols.sh bc2a3709940d47c8ac8e0a1fdf17ec801f015a00
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings.sh 347d974d143cf132f953b565fbc03026f19fcb4d
-P 049c3c42fdefea8de7ec7008871963e37ce2d7bc
-R 06582f4582a8157c228d4b288a346794
+P 0206bc6f87bb9393218a380fc5b18039d334a8d8
+R 9437f6a8af920a11b9b18fbeccb53c6b
 U drh
-Z 0eb02a6eb0f61a953a539b049b2322b5
+Z d6270d9f0f6d36a33c5a8dae47c51fc0
diff --git a/manifest.uuid b/manifest.uuid
index a5c8a3d8b3..a78d2a2cc4 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-0206bc6f87bb9393218a380fc5b18039d334a8d8
\ No newline at end of file
+1bd72d0c616e20fdb395c72ecd96579090ae26cb
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index 972a2f608c..9e9677cc42 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -857,6 +857,8 @@ static int ptrmapGet(BtShared *pBt, Pgno key, u8 *pEType, Pgno *pPgno){
 */
 #define findCell(P,I) \
   ((P)->aData + ((P)->maskPage & get2byte(&(P)->aData[(P)->cellOffset+2*(I)])))
+#define findCellv2(D,M,O,I) (D+(M&get2byte(D+(O+2*(I)))))
+
 
 /*
 ** This a more complex version of findCell() that works for
@@ -6016,12 +6018,24 @@ static int balance_nonroot(
     memcpy(pOld->aData, apOld[i]->aData, pBt->pageSize);
 
     limit = pOld->nCell+pOld->nOverflow;
-    for(j=0; j<limit; j++){
-      assert( nCell<nMaxCells );
-      apCell[nCell] = findOverflowCell(pOld, j);
-      szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
-      nCell++;
-    }
+    if( pOld->nOverflow>0 ){
+      for(j=0; j<limit; j++){
+        assert( nCell<nMaxCells );
+        apCell[nCell] = findOverflowCell(pOld, j);
+        szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
+        nCell++;
+      }
+    }else{
+      u8 *aData = pOld->aData;
+      u16 maskPage = pOld->maskPage;
+      u16 cellOffset = pOld->cellOffset;
+      for(j=0; j<limit; j++){
+        assert( nCell<nMaxCells );
+        apCell[nCell] = findCellv2(aData, maskPage, cellOffset, j);
+        szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
+        nCell++;
+      }
+    }       
     if( i<nOld-1 && !leafData){
       u16 sz = (u16)szNew[i];
       u8 *pTemp;

From 5d9c9da6e847e7111fc93c592576edaff5ad8cdf Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Fri, 3 Jun 2011 20:11:17 +0000
Subject: [PATCH 26/30] Create and use a function especially for adding the
 ParseSchema opcode. This gives a small reduction in code and a small
 performance increase.

FossilOrigin-Name: 957b2ab67c6185f0e1062593d237de5c434a38bf
---
 manifest      | 22 +++++++++++-----------
 manifest.uuid |  2 +-
 src/alter.c   |  4 ++--
 src/build.c   |  9 ++++-----
 src/trigger.c |  5 ++---
 src/vdbe.h    |  1 +
 src/vdbeaux.c | 21 ++++++++++++++-------
 src/vtab.c    |  2 +-
 8 files changed, 36 insertions(+), 30 deletions(-)

diff --git a/manifest b/manifest
index b636720757..c00993097b 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Factor\san\s"if"\sout\sof\sa\sloop\sin\sbalance_nonroot()\sfor\sabout\sa\s1%\sperformance\nincrease.
-D 2011-06-03T17:50:49.782
+C Create\sand\suse\sa\sfunction\sespecially\sfor\sadding\sthe\sParseSchema\sopcode.\nThis\sgives\sa\ssmall\sreduction\sin\scode\sand\sa\ssmall\sperformance\sincrease.
+D 2011-06-03T20:11:17.958
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -115,7 +115,7 @@ F spec.template 86a4a43b99ebb3e75e6b9a735d5fd293a24e90ca
 F sqlite.pc.in 42b7bf0d02e08b9e77734a47798d1a55a9e0716b
 F sqlite3.1 6be1ad09113570e1fc8dcaff84c9b0b337db5ffc
 F sqlite3.pc.in ae6f59a76e862f5c561eb32a380228a02afc3cad
-F src/alter.c 280f5c04b11b492703a342222b3de0a999445280
+F src/alter.c ac80a0f31189f8b4a524ebf661e47e84536ee7f5
 F src/analyze.c a425d62e8fa9ebcb4359ab84ff0c62c6563d2e2a
 F src/attach.c 12c6957996908edc31c96d7c68d4942c2474405f
 F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
@@ -125,7 +125,7 @@ F src/btmutex.c 976f45a12e37293e32cae0281b15a21d48a8aaa7
 F src/btree.c 12aa3b71359c888984223cb2bcf691cf2d7753ae
 F src/btree.h f5d775cd6cfc7ac32a2535b70e8d2af48ef5f2ce
 F src/btreeInt.h 67978c014fa4f7cc874032dd3aacadd8db656bc3
-F src/build.c c10ab9e2c77ade99dee23554787f8acfc0c231fc
+F src/build.c 5a428625d21ad409514afb40ad083bee25dd957a
 F src/callback.c 0425c6320730e6d3981acfb9202c1bed9016ad1a
 F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c 7deec4534f3b5a0c3b4a4cbadf809d321f64f9c4
@@ -231,20 +231,20 @@ F src/test_vfstrace.c 0b884e06094a746da729119a2cabdc7aa790063d
 F src/test_wholenumber.c 6129adfbe7c7444f2e60cc785927f3aa74e12290
 F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
 F src/tokenize.c 7b0c9281b2368dc69135e7a50bd271de9af1b467
-F src/trigger.c 144cc18bb701f3286484aae4292a9531f09278c8
+F src/trigger.c c836a6caac16ba96611558922106858f6ca3d6bf
 F src/update.c 5bcb56e5c7380a2eecb0e71891dbd4ad7437748f
 F src/utf.c d83650c3ea08f7407bd9d0839d9885241c209c60
 F src/util.c 0f33bbbdfcc4a2d8cf20c3b2a16ffc3b57c58a70
 F src/vacuum.c 05513dca036a1e7848fe18d5ed1265ac0b32365e
 F src/vdbe.c edfa3827d7a6fac2425bc10c0eb6e54342d2fa56
-F src/vdbe.h d9c6123384189dc37d27beac1bf44688aa75b6cb
+F src/vdbe.h 5cf09e7ee8a3f7d93bc51f196a96550786afe7a1
 F src/vdbeInt.h ad84226cc0adcb1185c22b70696b235a1678bb45
 F src/vdbeapi.c 0eeadc75e44a30efd996d6af6e7c5a2488e35be8
-F src/vdbeaux.c 0505dc4f7ff3cf35e219fe0a20ab798a42772b8b
+F src/vdbeaux.c 0b2e2880f13af400a27c92a7673287c3eaec8b21
 F src/vdbeblob.c f024f0bf420f36b070143c32b15cc7287341ffd3
 F src/vdbemem.c 0498796b6ffbe45e32960d6a1f5adfb6e419883b
 F src/vdbetrace.c 5d0dc3d5fd54878cc8d6d28eb41deb8d5885b114
-F src/vtab.c 9ba8c7fdb7d39260c033a402f6032d3e7bc5d336
+F src/vtab.c 901791a47318c0562cd0c676a2c6ff1bc530e582
 F src/wal.c 0c70ad7b1cac6005fa5e2cbefd23ee05e391c290
 F src/wal.h 66b40bd91bc29a5be1c88ddd1f5ade8f3f48728a
 F src/walker.c 3112bb3afe1d85dc52317cb1d752055e9a781f8f
@@ -942,7 +942,7 @@ F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/symbols.sh bc2a3709940d47c8ac8e0a1fdf17ec801f015a00
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings.sh 347d974d143cf132f953b565fbc03026f19fcb4d
-P 0206bc6f87bb9393218a380fc5b18039d334a8d8
-R 9437f6a8af920a11b9b18fbeccb53c6b
+P 1bd72d0c616e20fdb395c72ecd96579090ae26cb
+R 80ecde493cfcd0f0a571171fe6ad9164
 U drh
-Z d6270d9f0f6d36a33c5a8dae47c51fc0
+Z 08497a0228f24f1156217359e2dbd164
diff --git a/manifest.uuid b/manifest.uuid
index a78d2a2cc4..67c1f2f89d 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-1bd72d0c616e20fdb395c72ecd96579090ae26cb
\ No newline at end of file
+957b2ab67c6185f0e1062593d237de5c434a38bf
\ No newline at end of file
diff --git a/src/alter.c b/src/alter.c
index aa3fa929f8..fb6d89de6f 100644
--- a/src/alter.c
+++ b/src/alter.c
@@ -358,14 +358,14 @@ static void reloadTableSchema(Parse *pParse, Table *pTab, const char *zName){
   /* Reload the table, index and permanent trigger schemas. */
   zWhere = sqlite3MPrintf(pParse->db, "tbl_name=%Q", zName);
   if( !zWhere ) return;
-  sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0, zWhere, P4_DYNAMIC);
+  sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere);
 
 #ifndef SQLITE_OMIT_TRIGGER
   /* Now, if the table is not stored in the temp database, reload any temp 
   ** triggers. Don't use IN(...) in case SQLITE_OMIT_SUBQUERY is defined. 
   */
   if( (zWhere=whereTempTriggers(pParse, pTab))!=0 ){
-    sqlite3VdbeAddOp4(v, OP_ParseSchema, 1, 0, 0, zWhere, P4_DYNAMIC);
+    sqlite3VdbeAddParseSchemaOp(v, 1, zWhere);
   }
 #endif
 }
diff --git a/src/build.c b/src/build.c
index afe2089325..97758cbcbd 100644
--- a/src/build.c
+++ b/src/build.c
@@ -1619,8 +1619,8 @@ void sqlite3EndTable(
 #endif
 
     /* Reparse everything to update our internal data structures */
-    sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0,
-        sqlite3MPrintf(db, "tbl_name='%q'",p->zName), P4_DYNAMIC);
+    sqlite3VdbeAddParseSchemaOp(v, iDb,
+               sqlite3MPrintf(db, "tbl_name='%q'", p->zName));
   }
 
 
@@ -2817,9 +2817,8 @@ Index *sqlite3CreateIndex(
     if( pTblName ){
       sqlite3RefillIndex(pParse, pIndex, iMem);
       sqlite3ChangeCookie(pParse, iDb);
-      sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0,
-         sqlite3MPrintf(db, "name='%q' AND type='index'", pIndex->zName), 
-         P4_DYNAMIC);
+      sqlite3VdbeAddParseSchemaOp(v, iDb,
+         sqlite3MPrintf(db, "name='%q' AND type='index'", pIndex->zName));
       sqlite3VdbeAddOp1(v, OP_Expire, 0);
     }
   }
diff --git a/src/trigger.c b/src/trigger.c
index 0f3f5bad39..6242de5e6c 100644
--- a/src/trigger.c
+++ b/src/trigger.c
@@ -301,9 +301,8 @@ void sqlite3FinishTrigger(
        pTrig->table, z);
     sqlite3DbFree(db, z);
     sqlite3ChangeCookie(pParse, iDb);
-    sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0, sqlite3MPrintf(
-        db, "type='trigger' AND name='%q'", zName), P4_DYNAMIC
-    );
+    sqlite3VdbeAddParseSchemaOp(v, iDb,
+        sqlite3MPrintf(db, "type='trigger' AND name='%q'", zName));
   }
 
   if( db->init.busy ){
diff --git a/src/vdbe.h b/src/vdbe.h
index 56f9eb51ca..e66ee3024d 100644
--- a/src/vdbe.h
+++ b/src/vdbe.h
@@ -172,6 +172,7 @@ int sqlite3VdbeAddOp3(Vdbe*,int,int,int,int);
 int sqlite3VdbeAddOp4(Vdbe*,int,int,int,int,const char *zP4,int);
 int sqlite3VdbeAddOp4Int(Vdbe*,int,int,int,int,int);
 int sqlite3VdbeAddOpList(Vdbe*, int nOp, VdbeOpList const *aOp);
+void sqlite3VdbeAddParseSchemaOp(Vdbe*,int,char*);
 void sqlite3VdbeChangeP1(Vdbe*, int addr, int P1);
 void sqlite3VdbeChangeP2(Vdbe*, int addr, int P2);
 void sqlite3VdbeChangeP3(Vdbe*, int addr, int P3);
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index 8181f01aa3..447ba57a1e 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -156,13 +156,6 @@ int sqlite3VdbeAddOp3(Vdbe *p, int op, int p1, int p2, int p3){
   pOp->p3 = p3;
   pOp->p4.p = 0;
   pOp->p4type = P4_NOTUSED;
-  p->expired = 0;
-  if( op==OP_ParseSchema ){
-    /* Any program that uses the OP_ParseSchema opcode needs to lock
-    ** all btrees. */
-    int j;
-    for(j=0; j<p->db->nDb; j++) sqlite3VdbeUsesBtree(p, j);
-  }
 #ifdef SQLITE_DEBUG
   pOp->zComment = 0;
   if( sqlite3VdbeAddopTrace ) sqlite3VdbePrintOp(0, i, &p->aOp[i]);
@@ -201,6 +194,20 @@ int sqlite3VdbeAddOp4(
   return addr;
 }
 
+/*
+** Add an OP_ParseSchema opcode.  This routine is broken out from
+** sqlite3VdbeAddOp4() since it needs to also local all btrees.
+**
+** The zWhere string must have been obtained from sqlite3_malloc().
+** This routine will take ownership of the allocated memory.
+*/
+void sqlite3VdbeAddParseSchemaOp(Vdbe *p, int iDb, char *zWhere){
+  int j;
+  int addr = sqlite3VdbeAddOp3(p, OP_ParseSchema, iDb, 0, 0);
+  sqlite3VdbeChangeP4(p, addr, zWhere, P4_DYNAMIC);
+  for(j=0; j<p->db->nDb; j++) sqlite3VdbeUsesBtree(p, j);
+}
+
 /*
 ** Add an opcode that includes the p4 value as an integer.
 */
diff --git a/src/vtab.c b/src/vtab.c
index dffd6a2664..223ef4e7bd 100644
--- a/src/vtab.c
+++ b/src/vtab.c
@@ -383,7 +383,7 @@ void sqlite3VtabFinishParse(Parse *pParse, Token *pEnd){
 
     sqlite3VdbeAddOp2(v, OP_Expire, 0, 0);
     zWhere = sqlite3MPrintf(db, "name='%q' AND type='table'", pTab->zName);
-    sqlite3VdbeAddOp4(v, OP_ParseSchema, iDb, 0, 0, zWhere, P4_DYNAMIC);
+    sqlite3VdbeAddParseSchemaOp(v, iDb, zWhere);
     sqlite3VdbeAddOp4(v, OP_VCreate, iDb, 0, 0, 
                          pTab->zName, sqlite3Strlen30(pTab->zName) + 1);
   }

From 3a61a5a2b534f357822851d7859a683212aaab72 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Fri, 3 Jun 2011 21:34:45 +0000
Subject: [PATCH 27/30] Performance enhancement to the blob-literal tokenizer.

FossilOrigin-Name: 61aa2031f1c5ae05e31077588a55194a9546262a
---
 manifest       | 12 ++++++------
 manifest.uuid  |  2 +-
 src/tokenize.c | 11 +++++------
 3 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/manifest b/manifest
index c00993097b..014b8a5783 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Create\sand\suse\sa\sfunction\sespecially\sfor\sadding\sthe\sParseSchema\sopcode.\nThis\sgives\sa\ssmall\sreduction\sin\scode\sand\sa\ssmall\sperformance\sincrease.
-D 2011-06-03T20:11:17.958
+C Performance\senhancement\sto\sthe\sblob-literal\stokenizer.
+D 2011-06-03T21:34:45.326
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -230,7 +230,7 @@ F src/test_vfs.c e7855568dfa1e0ba73668d273b65605d9f8b77e8
 F src/test_vfstrace.c 0b884e06094a746da729119a2cabdc7aa790063d
 F src/test_wholenumber.c 6129adfbe7c7444f2e60cc785927f3aa74e12290
 F src/test_wsd.c 41cadfd9d97fe8e3e4e44f61a4a8ccd6f7ca8fe9
-F src/tokenize.c 7b0c9281b2368dc69135e7a50bd271de9af1b467
+F src/tokenize.c c819d9f72168a035d545a5bdafe9b085b20df705
 F src/trigger.c c836a6caac16ba96611558922106858f6ca3d6bf
 F src/update.c 5bcb56e5c7380a2eecb0e71891dbd4ad7437748f
 F src/utf.c d83650c3ea08f7407bd9d0839d9885241c209c60
@@ -942,7 +942,7 @@ F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/symbols.sh bc2a3709940d47c8ac8e0a1fdf17ec801f015a00
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings.sh 347d974d143cf132f953b565fbc03026f19fcb4d
-P 1bd72d0c616e20fdb395c72ecd96579090ae26cb
-R 80ecde493cfcd0f0a571171fe6ad9164
+P 957b2ab67c6185f0e1062593d237de5c434a38bf
+R bd36ddd3c30f1348cf18f2599b20bbca
 U drh
-Z 08497a0228f24f1156217359e2dbd164
+Z fe6a860af7a1658c61a1531782a69559
diff --git a/manifest.uuid b/manifest.uuid
index 67c1f2f89d..01e044ed3e 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-957b2ab67c6185f0e1062593d237de5c434a38bf
\ No newline at end of file
+61aa2031f1c5ae05e31077588a55194a9546262a
\ No newline at end of file
diff --git a/src/tokenize.c b/src/tokenize.c
index 016a218262..b32989277e 100644
--- a/src/tokenize.c
+++ b/src/tokenize.c
@@ -353,13 +353,12 @@ int sqlite3GetToken(const unsigned char *z, int *tokenType){
       testcase( z[0]=='x' ); testcase( z[0]=='X' );
       if( z[1]=='\'' ){
         *tokenType = TK_BLOB;
-        for(i=2; (c=z[i])!=0 && c!='\''; i++){
-          if( !sqlite3Isxdigit(c) ){
-            *tokenType = TK_ILLEGAL;
-          }
+        for(i=2; sqlite3Isxdigit(z[i]); i++){}
+        if( z[i]!='\'' || i%2 ){
+          *tokenType = TK_ILLEGAL;
+          while( z[i] && z[i]!='\'' ){ i++; }
         }
-        if( i%2 || !c ) *tokenType = TK_ILLEGAL;
-        if( c ) i++;
+        if( z[i] ) i++;
         return i;
       }
       /* Otherwise fall through to the next case */

From 61d2fe955c2af8a24ab3829d143c8f9fd6324319 Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Fri, 3 Jun 2011 23:28:33 +0000
Subject: [PATCH 28/30] Performance improvements on memory copies inside of
 btree by moving 2 bytes at a time instead of just 1 byte at a time.

FossilOrigin-Name: 897f56a158ebe62758c9998e4941ae046c75fb99
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/btree.c   | 17 ++++++++++-------
 3 files changed, 17 insertions(+), 14 deletions(-)

diff --git a/manifest b/manifest
index 014b8a5783..7f9a970797 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Performance\senhancement\sto\sthe\sblob-literal\stokenizer.
-D 2011-06-03T21:34:45.326
+C Performance\simprovements\son\smemory\scopies\sinside\sof\sbtree\sby\smoving\s2\sbytes\nat\sa\stime\sinstead\sof\sjust\s1\sbyte\sat\sa\stime.
+D 2011-06-03T23:28:33.011
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -122,7 +122,7 @@ F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
 F src/backup.c 986c15232757f2873dff35ee3b35cbf935fc573c
 F src/bitvec.c af50f1c8c0ff54d6bdb7a80e2fceca5a93670bef
 F src/btmutex.c 976f45a12e37293e32cae0281b15a21d48a8aaa7
-F src/btree.c 12aa3b71359c888984223cb2bcf691cf2d7753ae
+F src/btree.c 9f214af284fae1e96f12989dcc4d26f247b502fc
 F src/btree.h f5d775cd6cfc7ac32a2535b70e8d2af48ef5f2ce
 F src/btreeInt.h 67978c014fa4f7cc874032dd3aacadd8db656bc3
 F src/build.c 5a428625d21ad409514afb40ad083bee25dd957a
@@ -942,7 +942,7 @@ F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/symbols.sh bc2a3709940d47c8ac8e0a1fdf17ec801f015a00
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings.sh 347d974d143cf132f953b565fbc03026f19fcb4d
-P 957b2ab67c6185f0e1062593d237de5c434a38bf
-R bd36ddd3c30f1348cf18f2599b20bbca
+P 61aa2031f1c5ae05e31077588a55194a9546262a
+R ee8453a74951d0e43529f6f62862f77e
 U drh
-Z fe6a860af7a1658c61a1531782a69559
+Z eb5472e3af1761c7727508ef6d936f22
diff --git a/manifest.uuid b/manifest.uuid
index 01e044ed3e..246d28ad64 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-61aa2031f1c5ae05e31077588a55194a9546262a
\ No newline at end of file
+897f56a158ebe62758c9998e4941ae046c75fb99
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index 9e9677cc42..ece4602159 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -5422,8 +5422,7 @@ static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
   }
   endPtr = &data[pPage->cellOffset + 2*pPage->nCell - 2];
   while( ptr<endPtr ){
-    ptr[0] = ptr[2];
-    ptr[1] = ptr[3];
+    *(u16*)ptr = *(u16*)&ptr[2];
     ptr += 2;
   }
   pPage->nCell--;
@@ -5464,6 +5463,7 @@ static void insertCell(
   int cellOffset;   /* Address of first cell pointer in data[] */
   u8 *data;         /* The content of the whole page */
   u8 *ptr;          /* Used for moving information around in data[] */
+  u8 *endPtr;       /* End of the loop */
 
   int nSkip = (iChild ? 4 : 0);
 
@@ -5514,9 +5514,11 @@ static void insertCell(
     if( iChild ){
       put4byte(&data[idx], iChild);
     }
-    for(j=end, ptr=&data[j]; j>ins; j-=2, ptr-=2){
-      ptr[0] = ptr[-2];
-      ptr[1] = ptr[-1];
+    ptr = &data[end];
+    endPtr = &data[ins];
+    while( ptr>endPtr ){
+      *(u16*)ptr = *(u16*)&ptr[-2];
+      ptr -= 2;
     }
     put2byte(&data[ins], idx);
     put2byte(&data[pPage->hdrOffset+3], pPage->nCell);
@@ -5561,10 +5563,11 @@ static void assemblePage(
   pCellptr = &data[pPage->cellOffset + nCell*2];
   cellbody = nUsable;
   for(i=nCell-1; i>=0; i--){
+    u16 sz = aSize[i];
     pCellptr -= 2;
-    cellbody -= aSize[i];
+    cellbody -= sz;
     put2byte(pCellptr, cellbody);
-    memcpy(&data[cellbody], apCell[i], aSize[i]);
+    memcpy(&data[cellbody], apCell[i], sz);
   }
   put2byte(&data[hdr+3], nCell);
   put2byte(&data[hdr+5], cellbody);

From afb9817f8c85b9a3e43edabfc84e079c8dd384ab Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Sat, 4 Jun 2011 01:43:53 +0000
Subject: [PATCH 29/30] Performance improvement to the btree search routine.

FossilOrigin-Name: 65db822f200bafe9abe59b33b17b2c643c17c5e8
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/btree.c   | 10 +++++-----
 3 files changed, 12 insertions(+), 12 deletions(-)

diff --git a/manifest b/manifest
index 7f9a970797..acedbbc719 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Performance\simprovements\son\smemory\scopies\sinside\sof\sbtree\sby\smoving\s2\sbytes\nat\sa\stime\sinstead\sof\sjust\s1\sbyte\sat\sa\stime.
-D 2011-06-03T23:28:33.011
+C Performance\simprovement\sto\sthe\sbtree\ssearch\sroutine.
+D 2011-06-04T01:43:53.858
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -122,7 +122,7 @@ F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
 F src/backup.c 986c15232757f2873dff35ee3b35cbf935fc573c
 F src/bitvec.c af50f1c8c0ff54d6bdb7a80e2fceca5a93670bef
 F src/btmutex.c 976f45a12e37293e32cae0281b15a21d48a8aaa7
-F src/btree.c 9f214af284fae1e96f12989dcc4d26f247b502fc
+F src/btree.c c19d7b35c8325b302d88d73e834642a7a96ee003
 F src/btree.h f5d775cd6cfc7ac32a2535b70e8d2af48ef5f2ce
 F src/btreeInt.h 67978c014fa4f7cc874032dd3aacadd8db656bc3
 F src/build.c 5a428625d21ad409514afb40ad083bee25dd957a
@@ -942,7 +942,7 @@ F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/symbols.sh bc2a3709940d47c8ac8e0a1fdf17ec801f015a00
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings.sh 347d974d143cf132f953b565fbc03026f19fcb4d
-P 61aa2031f1c5ae05e31077588a55194a9546262a
-R ee8453a74951d0e43529f6f62862f77e
+P 897f56a158ebe62758c9998e4941ae046c75fb99
+R 84139bde7a129a9544042a4a85d415c4
 U drh
-Z eb5472e3af1761c7727508ef6d936f22
+Z 4316427fea8d5aeb84c01ffb6d821ecd
diff --git a/manifest.uuid b/manifest.uuid
index 246d28ad64..e0e3846b64 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-897f56a158ebe62758c9998e4941ae046c75fb99
\ No newline at end of file
+65db822f200bafe9abe59b33b17b2c643c17c5e8
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index ece4602159..640d48b452 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -4453,7 +4453,7 @@ int sqlite3BtreeMovetoUnpacked(
   }
   assert( pCur->apPage[0]->intKey || pIdxKey );
   for(;;){
-    int lwr, upr;
+    int lwr, upr, idx;
     Pgno chldPg;
     MemPage *pPage = pCur->apPage[pCur->iPage];
     int c;
@@ -4469,14 +4469,14 @@ int sqlite3BtreeMovetoUnpacked(
     lwr = 0;
     upr = pPage->nCell-1;
     if( biasRight ){
-      pCur->aiIdx[pCur->iPage] = (u16)upr;
+      pCur->aiIdx[pCur->iPage] = (u16)(idx = upr);
     }else{
-      pCur->aiIdx[pCur->iPage] = (u16)((upr+lwr)/2);
+      pCur->aiIdx[pCur->iPage] = (u16)(idx = (upr+lwr)/2);
     }
     for(;;){
-      int idx = pCur->aiIdx[pCur->iPage]; /* Index of current cell in pPage */
       u8 *pCell;                          /* Pointer to current cell in pPage */
 
+      assert( idx==pCur->aiIdx[pCur->iPage] );
       pCur->info.nSize = 0;
       pCell = findCell(pPage, idx) + pPage->childPtrSize;
       if( pPage->intKey ){
@@ -4559,7 +4559,7 @@ int sqlite3BtreeMovetoUnpacked(
       if( lwr>upr ){
         break;
       }
-      pCur->aiIdx[pCur->iPage] = (u16)((lwr+upr)/2);
+      pCur->aiIdx[pCur->iPage] = (u16)(idx = (lwr+upr)/2);
     }
     assert( lwr==upr+1 );
     assert( pPage->isInit );

From 2ce71b4e7a11d23d9267f4c3e2714adde454ddcd Mon Sep 17 00:00:00 2001
From: drh <drh@noemail.net>
Date: Mon, 6 Jun 2011 13:38:11 +0000
Subject: [PATCH 30/30] Add assert() statements to verify that u16 pointers
 associated with the enhancement in [897f56a158] are always 2-byte aligned.

FossilOrigin-Name: 98ccfa930e8e5f10808a518e3e22e85e8a8a65c2
---
 manifest      | 12 ++++++------
 manifest.uuid |  2 +-
 src/btree.c   |  2 ++
 3 files changed, 9 insertions(+), 7 deletions(-)

diff --git a/manifest b/manifest
index acedbbc719..9f7ebae4ea 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Performance\simprovement\sto\sthe\sbtree\ssearch\sroutine.
-D 2011-06-04T01:43:53.858
+C Add\sassert()\sstatements\sto\sverify\sthat\su16\spointers\sassociated\swith\nthe\senhancement\sin\s[897f56a158]\sare\salways\s2-byte\saligned.
+D 2011-06-06T13:38:11.704
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 11dcc00a8d0e5202def00e81732784fb0cc4fe1d
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -122,7 +122,7 @@ F src/auth.c 523da7fb4979469955d822ff9298352d6b31de34
 F src/backup.c 986c15232757f2873dff35ee3b35cbf935fc573c
 F src/bitvec.c af50f1c8c0ff54d6bdb7a80e2fceca5a93670bef
 F src/btmutex.c 976f45a12e37293e32cae0281b15a21d48a8aaa7
-F src/btree.c c19d7b35c8325b302d88d73e834642a7a96ee003
+F src/btree.c 8c46f0ab69ad9549c75a3a91fed87abdaa743e2f
 F src/btree.h f5d775cd6cfc7ac32a2535b70e8d2af48ef5f2ce
 F src/btreeInt.h 67978c014fa4f7cc874032dd3aacadd8db656bc3
 F src/build.c 5a428625d21ad409514afb40ad083bee25dd957a
@@ -942,7 +942,7 @@ F tool/split-sqlite3c.tcl d9be87f1c340285a3e081eb19b4a247981ed290c
 F tool/symbols.sh bc2a3709940d47c8ac8e0a1fdf17ec801f015a00
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings.sh 347d974d143cf132f953b565fbc03026f19fcb4d
-P 897f56a158ebe62758c9998e4941ae046c75fb99
-R 84139bde7a129a9544042a4a85d415c4
+P 65db822f200bafe9abe59b33b17b2c643c17c5e8
+R 6f20bbc84376df4d202ff7744a749f24
 U drh
-Z 4316427fea8d5aeb84c01ffb6d821ecd
+Z b952c48c970134cec62f175ed76931db
diff --git a/manifest.uuid b/manifest.uuid
index e0e3846b64..4a6c7d51ec 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-65db822f200bafe9abe59b33b17b2c643c17c5e8
\ No newline at end of file
+98ccfa930e8e5f10808a518e3e22e85e8a8a65c2
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index 640d48b452..3d7162dbb3 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -5421,6 +5421,7 @@ static void dropCell(MemPage *pPage, int idx, int sz, int *pRC){
     return;
   }
   endPtr = &data[pPage->cellOffset + 2*pPage->nCell - 2];
+  assert( (SQLITE_PTR_TO_INT(ptr)&1)==0 );  /* ptr is always 2-byte aligned */
   while( ptr<endPtr ){
     *(u16*)ptr = *(u16*)&ptr[2];
     ptr += 2;
@@ -5516,6 +5517,7 @@ static void insertCell(
     }
     ptr = &data[end];
     endPtr = &data[ins];
+    assert( (SQLITE_PTR_TO_INT(ptr)&1)==0 );  /* ptr is always 2-byte aligned */
     while( ptr>endPtr ){
       *(u16*)ptr = *(u16*)&ptr[-2];
       ptr -= 2;