diff --git a/ext/session/session1.test b/ext/session/session1.test
index e97aa3c20d..09d35af7fc 100644
--- a/ext/session/session1.test
+++ b/ext/session/session1.test
@@ -569,5 +569,17 @@ do_changeset_test 10.1.2 S "
 "
 do_test 10.1.4 { S delete } {}
 
+#-------------------------------------------------------------------------
+# Test the effect of updating a column from 0.0 to 0.0.
+#
+reset_db
+do_execsql_test 11.1 {
+  CREATE TABLE t1(a INTEGER PRIMARY KEY, b REAL);
+  INSERT INTO t1 VALUES(1, 0.0);
+}
+do_iterator_test 11.2 * {
+  UPDATE t1 SET b = 0.0;
+} {
+}
 
 finish_test
diff --git a/manifest b/manifest
index a38df93cf5..035b02b58a 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C First\sattempt\sat\sa\sutility\sprogram\sto\scompute\ssqlite_stat1\swithout\sdoing\na\sfull\stable\sscan.
-D 2016-10-25T13:57:40.551
+C Merge\srecent\strunk\schanges,\sand\sespecially\sthe\sPRAGMA\sindex_info\senhancement\nwhich\sis\sneeded\son\sthis\sbranch.
+D 2016-10-25T17:28:49.402
 F Makefile.in 6fd48ffcf7c2deea7499062d1f3747f986c19678
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc 5151cc64c4c05f3455f4f692ad11410a810d937f
@@ -284,7 +284,7 @@ F ext/rtree/sqlite3rtree.h 9c5777af3d2921c7b4ae4954e8e5697502289d28
 F ext/rtree/tkt3363.test 142ab96eded44a3615ec79fba98c7bde7d0f96de
 F ext/rtree/viewrtree.tcl eea6224b3553599ae665b239bd827e182b466024
 F ext/session/changeset.c 4ccbaa4531944c24584bf6a61ba3a39c62b6267a
-F ext/session/session1.test 98f384736e2bc21ccf5ed81bdadcff4ad863393b
+F ext/session/session1.test e5125b216d1e8c91e0984b361b0b68529e7c5dfb
 F ext/session/session2.test 284de45abae4cc1082bc52012ee81521d5ac58e0
 F ext/session/session3.test a7a9ce59b8d1e49e2cc23d81421ac485be0eea01
 F ext/session/session4.test 457b02bdc349eb01151e54de014df77abd3c08c8
@@ -330,7 +330,7 @@ F src/auth.c 930b376a9c56998557367e6f7f8aaeac82a2a792
 F src/backup.c faf17e60b43233c214aae6a8179d24503a61e83b
 F src/bitvec.c 3ee4c8b2c94ed3a7377256e18199e6ff5cf33f63
 F src/btmutex.c bc87dd3b062cc26edfe79918de2200ccb8d41e73
-F src/btree.c da29550955aba3930c31d550e32be689c7efb3ce
+F src/btree.c c0921ff5144702aecc69207025c99d9182d8baf0
 F src/btree.h 012576c1d0000e96ccc785c6fe22b4be8211f0d9
 F src/btreeInt.h c18b7d2a3494695133e4e60ee36061d37f45d9a5
 F src/build.c e22e66fb34e1e50bb7869a510923bfe58db3071a
@@ -380,7 +380,7 @@ F src/parse.y 07f68096c97093793ed04d69db8bb75e55c3e00e
 F src/pcache.c 5ff2a08f76a9c1b22f43eb063b7068fb085465ac
 F src/pcache.h 2cedcd8407eb23017d92790b112186886e179490
 F src/pcache1.c e3967219b2a92b9edcb9324a4ba75009090d3953
-F src/pragma.c 7e3bbf3c8d28a91d76f5cb91a7733fde43f13fe0
+F src/pragma.c 6ca8fb0a4da012c4ec4e92c76d868dca97ac6a03
 F src/pragma.h 74d46e32bdc7abb2d01710162ff96cfb483699b6
 F src/prepare.c b1140c3d0cf59bc85ace00ce363153041b424b7a
 F src/printf.c a5f0ca08ddede803c241266abb46356ec748ded1
@@ -456,9 +456,9 @@ F src/util.c 3e2da6101888d073e79ecc6af5e0a2f70fa1e498
 F src/vacuum.c 913970b9d86dd6c2b8063ef1af421880f1464ec3
 F src/vdbe.c 55ea5eb95860106a8f665231f8d0c6b55dbf8974
 F src/vdbe.h c044be7050ac6bf596eecc6ab159f5dbc020a3b7
-F src/vdbeInt.h 0a18713d0a2fec6807d076bd333d9bf3e57530cd
-F src/vdbeapi.c 8272f9342c39ab8d7eb4b9decc6caa7bc75b7d83
-F src/vdbeaux.c 7229203e4e4a3b6eaeeddc807c2287d912c0da74
+F src/vdbeInt.h d8a56a491b752dbb5f671963b8c861ec72ea875e
+F src/vdbeapi.c 97129bec6b1553da50d8e73f523c278bda66d9f6
+F src/vdbeaux.c 52d9b840859f260ce8418be9333dd77c902e1c74
 F src/vdbeblob.c 3e82a797b60c3b9fed7b8de8c539ca7607874937
 F src/vdbemem.c fcdd73a2001a673f48a244a77b1038928ae729c9
 F src/vdbesort.c 91fda3909326860382b0ca8aa251e609c6a9d62c
@@ -1373,7 +1373,7 @@ F test/wal2.test 56b0bc95b8693a0be294f8d210c49025dd094bd7
 F test/wal3.test 2a93004bc0fb2b5c29888964024695bade278ab2
 F test/wal4.test 4744e155cd6299c6bd99d3eab1c82f77db9cdb3c
 F test/wal5.test 9c11da7aeccd83a46d79a556ad11a18d3cb15aa9
-F test/wal6.test a9d6aa635b9d63607dabdc11406f5f96ca986635
+F test/wal6.test 504b24ddb3a75d4b7a6e7c09dc7563622e652fd2
 F test/wal64k.test 163655ecd2cb8afef4737cac2a40fdd2eeaf20b8
 F test/wal7.test 2ae8f427d240099cc4b2dfef63cff44e2a68a1bd
 F test/wal8.test d9df3fba4caad5854ed69ed673c68482514203c8
@@ -1429,7 +1429,7 @@ F test/with1.test cef099a491eac9874f2c28bd2dc86394fb3e47b3
 F test/with2.test 2b40da883658eb74ad8ad06afabe11a408e7fb87
 F test/with3.test 511bacdbe41c49cf34f9fd1bd3245fe1575bca98
 F test/withM.test 693b61765f2b387b5e3e24a4536e2e82de15ff64
-F test/without_rowid1.test 1a7b9bd51b899928d327052df9741d2fe8dbe701
+F test/without_rowid1.test eaac24556ed2dfaf84d8a32fac46229bd61b1015
 F test/without_rowid2.test af260339f79d13cb220288b67cd287fbcf81ad99
 F test/without_rowid3.test aad4f9d383e199349b6c7e508a778f7dff5dff79
 F test/without_rowid4.test 4e08bcbaee0399f35d58b5581881e7a6243d458a
@@ -1528,7 +1528,7 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 04fe12b590ab67e40cd079b5e614b787f5f525ad
-R bd47d064e2ed9e25c0899a770a248208
+P 7b83581a43384fe81dc319482e03be0df45ab25d fe49fb03133fec8bed51c2e2c1b6848ab9fc563e
+R dc40a5d5b8b329a8e831d814ba1f0d9d
 U drh
-Z d3e8fe3b1d555eec50042b333c79640e
+Z b7c4393dfca2a201afed4cf76221890b
diff --git a/manifest.uuid b/manifest.uuid
index 19d3391591..6148524a44 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-7b83581a43384fe81dc319482e03be0df45ab25d
\ No newline at end of file
+c3570e462a41586487c4ab3bd08129affe8bed3c
\ No newline at end of file
diff --git a/src/btree.c b/src/btree.c
index 5f28eb9c54..fe140e5387 100644
--- a/src/btree.c
+++ b/src/btree.c
@@ -4864,9 +4864,12 @@ static int moveToRoot(BtCursor *pCur){
   }
 
   if( pCur->iPage>=0 ){
-    while( pCur->iPage ){
-      assert( pCur->apPage[pCur->iPage]!=0 );
-      releasePageNotNull(pCur->apPage[pCur->iPage--]);
+    if( pCur->iPage ){
+      do{
+        assert( pCur->apPage[pCur->iPage]!=0 );
+        releasePageNotNull(pCur->apPage[pCur->iPage--]);
+      }while( pCur->iPage);
+      goto skip_init;
     }
   }else if( pCur->pgnoRoot==0 ){
     pCur->eState = CURSOR_INVALID;
@@ -4877,7 +4880,7 @@ static int moveToRoot(BtCursor *pCur){
                         0, pCur->curPagerFlags);
     if( rc!=SQLITE_OK ){
       pCur->eState = CURSOR_INVALID;
-      return rc;
+       return rc;
     }
     pCur->iPage = 0;
     pCur->curIntKey = pCur->apPage[0]->intKey;
@@ -4900,10 +4903,12 @@ static int moveToRoot(BtCursor *pCur){
     return SQLITE_CORRUPT_BKPT;
   }
 
+skip_init:  
   pCur->aiIdx[0] = 0;
   pCur->info.nSize = 0;
   pCur->curFlags &= ~(BTCF_AtLast|BTCF_ValidNKey|BTCF_ValidOvfl);
 
+  pRoot = pCur->apPage[0];
   if( pRoot->nCell>0 ){
     pCur->eState = CURSOR_VALID;
   }else if( !pRoot->leaf ){
diff --git a/src/pragma.c b/src/pragma.c
index c641f448cb..e725b6cef0 100644
--- a/src/pragma.c
+++ b/src/pragma.c
@@ -1113,6 +1113,10 @@ void sqlite3Pragma(
     Index *pIdx;
     Table *pTab;
     pIdx = sqlite3FindIndex(db, zRight, zDb);
+    if( pIdx==0 ){
+      pTab = sqlite3FindTable(db, zRight, zDb);
+      if( pTab && !HasRowid(pTab) ) pIdx = sqlite3PrimaryKeyIndex(pTab);
+    }
     if( pIdx ){
       static const char *azCol[] = {
          "seqno", "cid", "name", "desc", "coll", "key"
diff --git a/src/vdbeInt.h b/src/vdbeInt.h
index 1c6ee3f63b..86445cef66 100644
--- a/src/vdbeInt.h
+++ b/src/vdbeInt.h
@@ -430,8 +430,8 @@ struct PreUpdate {
   int iNewReg;                    /* Register for new.* values */
   i64 iKey1;                      /* First key value passed to hook */
   i64 iKey2;                      /* Second key value passed to hook */
-  int iPKey;                      /* If not negative index of IPK column */
   Mem *aNew;                      /* Array of new.* values */
+  Table *pTab;                    /* Schema object being upated */          
 };
 
 /*
diff --git a/src/vdbeapi.c b/src/vdbeapi.c
index 5956943af0..645ef1c864 100644
--- a/src/vdbeapi.c
+++ b/src/vdbeapi.c
@@ -1710,9 +1710,14 @@ int sqlite3_preupdate_old(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
   if( iIdx>=p->pUnpacked->nField ){
     *ppValue = (sqlite3_value *)columnNullValue();
   }else{
+    Mem *pMem = *ppValue = &p->pUnpacked->aMem[iIdx];
     *ppValue = &p->pUnpacked->aMem[iIdx];
-    if( iIdx==p->iPKey ){
-      sqlite3VdbeMemSetInt64(*ppValue, p->iKey1);
+    if( iIdx==p->pTab->iPKey ){
+      sqlite3VdbeMemSetInt64(pMem, p->iKey1);
+    }else if( p->pTab->aCol[iIdx].affinity==SQLITE_AFF_REAL ){
+      if( pMem->flags & MEM_Int ){
+        sqlite3VdbeMemRealify(pMem);
+      }
     }
   }
 
@@ -1789,7 +1794,7 @@ int sqlite3_preupdate_new(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
       pMem = (sqlite3_value *)columnNullValue();
     }else{
       pMem = &pUnpack->aMem[iIdx];
-      if( iIdx==p->iPKey ){
+      if( iIdx==p->pTab->iPKey ){
         sqlite3VdbeMemSetInt64(pMem, p->iKey2);
       }
     }
@@ -1810,7 +1815,7 @@ int sqlite3_preupdate_new(sqlite3 *db, int iIdx, sqlite3_value **ppValue){
     assert( iIdx>=0 && iIdx<p->pCsr->nField );
     pMem = &p->aNew[iIdx];
     if( pMem->flags==0 ){
-      if( iIdx==p->iPKey ){
+      if( iIdx==p->pTab->iPKey ){
         sqlite3VdbeMemSetInt64(pMem, p->iKey2);
       }else{
         rc = sqlite3VdbeMemCopy(pMem, &p->v->aMem[p->iNewReg+1+iIdx]);
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index df4fb2cdd0..596ab30c7b 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -4617,7 +4617,7 @@ void sqlite3VdbePreUpdateHook(
   preupdate.keyinfo.aSortOrder = (u8*)&fakeSortOrder;
   preupdate.iKey1 = iKey1;
   preupdate.iKey2 = iKey2;
-  preupdate.iPKey = pTab->iPKey;
+  preupdate.pTab = pTab;
 
   db->pPreUpdate = &preupdate;
   db->xPreUpdateCallback(db->pPreUpdateArg, db, op, zDb, zTbl, iKey1, iKey2);
diff --git a/test/wal6.test b/test/wal6.test
index 2574a64a84..92831f1fb0 100644
--- a/test/wal6.test
+++ b/test/wal6.test
@@ -234,5 +234,34 @@ do_test 4.4.2 {
   catchsql { SELECT * FROM t2 } db2 
 } {1 {database disk image is malformed}}
 
+#-------------------------------------------------------------------------
+# Confirm that it is possible to get an SQLITE_BUSY_SNAPSHOT error from
+# "BEGIN EXCLUSIVE" if the connection already has an open read-transaction.
+#
+reset_db
+sqlite3 db2 test.db
+do_execsql_test 5.1 {
+  PRAGMA journal_mode = wal;
+  CREATE TABLE t1(x, y);
+  INSERT INTO t1 VALUES(1, 2);
+  INSERT INTO t1 VALUES(3, 4);
+} {wal}
+do_test 5.2 {
+  set res [list]
+  db eval {
+    SELECT * FROM t1
+  } {
+    if {$x==1} {
+      db2 eval { INSERT INTO t1 VALUES(5, 6) }
+    } 
+    if {$x==3} {
+      set res [catchsql {BEGIN EXCLUSIVE}]
+      lappend res [sqlite3_extended_errcode db]
+    } 
+  }
+  set res
+} {1 {database is locked} SQLITE_BUSY_SNAPSHOT}
+
+
 
 finish_test
diff --git a/test/without_rowid1.test b/test/without_rowid1.test
index 0c77773abb..23fac402ff 100644
--- a/test/without_rowid1.test
+++ b/test/without_rowid1.test
@@ -328,5 +328,24 @@ do_catchsql_test 7.3 {
   ) WITHOUT ROWID;
 } {1 {no such column: rowid}}
 
+# The PRAGMA index_info and index_xinfo pragmas work on 
+# WITHOUT ROWID tables too, but not on rowid tables.
+#
+do_execsql_test 8.1 {
+  CREATE TABLE t80a(a TEXT, b INT, c BLOB, PRIMARY KEY(c,b));
+  PRAGMA index_info(t80a);
+} {}
+do_execsql_test 8.2 {
+  PRAGMA index_xinfo(t80a);
+} {}
+do_execsql_test 8.3 {
+  CREATE TABLE t80b(a TEXT, b INT, c BLOB, PRIMARY KEY(c,b)) WITHOUT ROWID;
+  PRAGMA index_info(t80b);
+} {0 2 c 1 1 b}
+do_execsql_test 8.4 {
+  PRAGMA index_xinfo(t80b);
+} {0 2 c 0 BINARY 1 1 1 b 0 BINARY 1 2 0 a 0 BINARY 0}
+
+
   
 finish_test