Add the --recovery-mode option to the CLI ".dump" command. This involves

enhancing the "PRAGMA reverse_unordered_selects" command to accept a "TOGGLE"
option.  Recovery mode used to be always on.  Now it is opt-in.  Not sure this
is the correct approach.  Also not sure if TOGGLE is a good feature to have
on boolean PRAGMA statements.

FossilOrigin-Name: 5dc82a155dee76e4c8c12e8e62284a10a52a43c8

manifest

@@ -1,5 +1,5 @@
-C Begin\smoving\sseparate\sboolean\svariables\sin\sthe\sShellState\sobject\sof\sthe\sCLI\ninto\sthe\sshellFlgs\sbitmask.
-D 2017-03-09T13:50:49.349
+C Add\sthe\s--recovery-mode\soption\sto\sthe\sCLI\s".dump"\scommand.\s\sThis\sinvolves\nenhancing\sthe\s"PRAGMA\sreverse_unordered_selects"\scommand\sto\saccept\sa\s"TOGGLE"\noption.\s\sRecovery\smode\sused\sto\sbe\salways\son.\s\sNow\sit\sis\sopt-in.\s\sNot\ssure\sthis\nis\sthe\scorrect\sapproach.\s\sAlso\snot\ssure\sif\sTOGGLE\sis\sa\sgood\sfeature\sto\shave\non\sboolean\sPRAGMA\sstatements.
+D 2017-03-09T16:32:39.526
 F Makefile.in edb6bcdd37748d2b1c3422ff727c748df7ffe918
 F Makefile.linux-gcc 7bc79876b875010e8c8f9502eb935ca92aa3c434
 F Makefile.msc a89ea37ab5928026001569f056973b9059492fe2
@@ -392,7 +392,7 @@ F src/parse.y 48b03113704ee8bd78ee6996d81de7fbee22e105
 F src/pcache.c 62835bed959e2914edd26afadfecce29ece0e870
 F src/pcache.h 2cedcd8407eb23017d92790b112186886e179490
 F src/pcache1.c e3967219b2a92b9edcb9324a4ba75009090d3953
-F src/pragma.c b7bf4f1dd9cdcdd3f72f0bdbce3502d69d0f48ba
+F src/pragma.c 6d0dd6879a9a8f18a2aad9c0cf34ccaa66bf3de9
 F src/pragma.h c9c763958fec92b04125571472c9500b351c5f7f
 F src/prepare.c b1140c3d0cf59bc85ace00ce363153041b424b7a
 F src/printf.c 67427bbee66d891fc6f6f5aada857e9cdb368c1c
@@ -400,7 +400,7 @@ F src/random.c 80f5d666f23feb3e6665a6ce04c7197212a88384
 F src/resolve.c 3e518b962d932a997fae373366880fc028c75706
 F src/rowset.c 7b7e7e479212e65b723bf40128c7b36dc5afdfac
 F src/select.c d12f3539f80db38b09015561b569e0eb1c4b6c5f
-F src/shell.c 397e51c3eeb3a9dc21667a0a384eb14403cc5eea
+F src/shell.c 9eb1fe6b682d86b5af82aa745132f436a2525a83
 F src/sqlite.h.in 4d0c08f8640c586564a7032b259c5f69bf397850
 F src/sqlite3.rc 5121c9e10c3964d5755191c80dd1180c122fc3a8
 F src/sqlite3ext.h 8648034aa702469afb553231677306cc6492a1ae
@@ -1564,7 +1564,10 @@ F vsixtest/vsixtest.tcl 6a9a6ab600c25a91a7acc6293828957a386a8a93
 F vsixtest/vsixtest.vcxproj.data 2ed517e100c66dc455b492e1a33350c1b20fbcdc
 F vsixtest/vsixtest.vcxproj.filters 37e51ffedcdb064aad6ff33b6148725226cd608e
 F vsixtest/vsixtest_TemporaryKey.pfx e5b1b036facdb453873e7084e1cae9102ccc67a0
-P 2ea300fb8f7c497f3f092dc91f4305d8431c27d9
-R 193fb708e3eeb9be14d6692d9fad8ed4
+P 50eec5d9aa38fab1a85d788356ffdaf6c35d9ece
+R 51880737be8d6b044d8d1303684ea6d0
+T *branch * dump-recovery
+T *sym-dump-recovery *
+T -sym-trunk *
 U drh
-Z 6ea8a21fbd5a369fc4273386c415b1f4
+Z f19b0ff5084fef69a5f8e22c2e8f27d1

manifest.uuid

@@ -1 +1 @@
-50eec5d9aa38fab1a85d788356ffdaf6c35d9ece
+5dc82a155dee76e4c8c12e8e62284a10a52a43c8

src/pragma.c

@@ -1045,12 +1045,15 @@ void sqlite3Pragma(
         mask &= ~(SQLITE_WriteSchema);
       }
 #endif
-
-      if( sqlite3GetBoolean(zRight, 0) ){
+      if( sqlite3StrICmp(zRight, "toggle")==0 ){
+        db->flags ^= mask;
+      }else if( sqlite3GetBoolean(zRight, 0) ){
         db->flags |= mask;
       }else{
         db->flags &= ~mask;
-        if( mask==SQLITE_DeferFKs ) db->nDeferredImmCons = 0;
+      }
+      if( mask==SQLITE_DeferFKs && (db->flags & mask)==0 ){
+        db->nDeferredImmCons = 0;
       }
 
       /* Many of the flag-pragmas modify the code generated by the SQL 

src/shell.c

@@ -1410,6 +1410,7 @@ struct ShellState {
 #define SHFLG_PreserveRowid  0x00000010 /* .dump preserves rowid values */
 #define SHFLG_CountChanges   0x00000020 /* .changes setting */
 #define SHFLG_Echo           0x00000040 /* .echo or --echo setting */
+#define SHFLG_RecoveryMode   0x00000080 /* The --recovery-mode flag for .dump */
 
 /*
 ** Macros for testing and setting shellFlgs
@@ -2219,7 +2220,7 @@ static int display_stats(
     sqlite3_status(SQLITE_STATUS_MALLOC_COUNT, &iCur, &iHiwtr, bReset);
     raw_printf(pArg->out, "Number of Outstanding Allocations:   %d (max %d)\n",
             iCur, iHiwtr);
-    if( pArg->shellFlgs & SHFLG_Pagecache ){
+    if( ShellHasFlag(pArg, SHFLG_Pagecache) ){
       iHiwtr = iCur = -1;
       sqlite3_status(SQLITE_STATUS_PAGECACHE_USED, &iCur, &iHiwtr, bReset);
       raw_printf(pArg->out,
@@ -2231,7 +2232,7 @@ static int display_stats(
     raw_printf(pArg->out,
             "Number of Pcache Overflow Bytes:     %d (max %d) bytes\n",
             iCur, iHiwtr);
-    if( pArg->shellFlgs & SHFLG_Scratch ){
+    if( ShellHasFlag(pArg, SHFLG_Scratch) ){
       iHiwtr = iCur = -1;
       sqlite3_status(SQLITE_STATUS_SCRATCH_USED, &iCur, &iHiwtr, bReset);
       raw_printf(pArg->out,
@@ -2264,7 +2265,7 @@ static int display_stats(
   }
 
   if( pArg && pArg->out && db ){
-    if( pArg->shellFlgs & SHFLG_Lookaside ){
+    if( ShellHasFlag(pArg, SHFLG_Lookaside) ){
       iHiwtr = iCur = -1;
       sqlite3_db_status(db, SQLITE_DBSTATUS_LOOKASIDE_USED,
                         &iCur, &iHiwtr, bReset);
@@ -2946,6 +2947,14 @@ static int dump_callback(void *pArg, int nArg, char **azArg, char **azCol){
     p->zDestTable = sTable.z;
     p->mode = p->cMode = MODE_Insert;
     rc = shell_exec(p->db, sSelect.z, shell_callback, p, 0);
+    if( (rc&0xff)==SQLITE_CORRUPT ){
+      raw_printf(p->out, "/****** CORRUPTION ERROR *******/\n");
+      if( ShellHasFlag(p, SHFLG_RecoveryMode) ){
+        sqlite3_exec(p->db, "PRAGMA reverse_unordered_selects=TOGGLE",0,0,0);
+        shell_exec(p->db, sSelect.z, shell_callback, p, 0);
+        sqlite3_exec(p->db, "PRAGMA reverse_unordered_selects=TOGGLE",0,0,0);
+      }
+    }
     p->zDestTable = savedDestTable;
     p->mode = savedMode;
     freeText(&sTable);
@@ -2959,8 +2968,9 @@ static int dump_callback(void *pArg, int nArg, char **azArg, char **azCol){
 ** Run zQuery.  Use dump_callback() as the callback routine so that
 ** the contents of the query are output as SQL statements.
 **
-** If we get a SQLITE_CORRUPT error, rerun the query after appending
-** "ORDER BY rowid DESC" to the end.
+** If we get a SQLITE_CORRUPT error and the --recovery-mode flag is
+** set, then rerun the query in reverse order to try to get more
+** data.
 */
 static int run_schema_dump_query(
   ShellState *p,
@@ -2969,7 +2979,7 @@ static int run_schema_dump_query(
   int rc;
   char *zErr = 0;
   rc = sqlite3_exec(p->db, zQuery, dump_callback, p, &zErr);
-  if( rc==SQLITE_CORRUPT ){
+  if( rc==SQLITE_CORRUPT && ShellHasFlag(p, SHFLG_RecoveryMode) ){
     char *zQ2;
     int len = strlen30(zQuery);
     raw_printf(p->out, "/****** CORRUPTION ERROR *******/\n");
@@ -4570,7 +4580,7 @@ static int do_meta_command(char *zLine, ShellState *p){
   if( c=='d' && strncmp(azArg[0], "dump", n)==0 ){
     const char *zLike = 0;
     int i;
-    ShellClearFlag(p, SHFLG_PreserveRowid);
+    ShellClearFlag(p, SHFLG_PreserveRowid|SHFLG_RecoveryMode);
     for(i=1; i<nArg; i++){
       if( azArg[i][0]=='-' ){
         const char *z = azArg[i]+1;
@@ -4578,8 +4588,13 @@ static int do_meta_command(char *zLine, ShellState *p){
         if( strcmp(z,"preserve-rowids")==0 ){
           ShellSetFlag(p, SHFLG_PreserveRowid);
         }else
+        if( strcmp(z,"recovery-mode")==0 ){
+          ShellSetFlag(p, SHFLG_RecoveryMode);
+        }else
         {
-          raw_printf(stderr, "Unknown option \"%s\" on \".dump\"\n", azArg[i]);
+          raw_printf(stderr, "Unknown option \"%s\" on \".dump\"\n"
+                  "Should be one of: --preserve-rowids --recovery-mode\n",
+                  azArg[i]);
           rc = 1;
           goto meta_command_exit;
         }
@@ -4598,10 +4613,12 @@ static int do_meta_command(char *zLine, ShellState *p){
     raw_printf(p->out, "PRAGMA foreign_keys=OFF;\n");
     raw_printf(p->out, "BEGIN TRANSACTION;\n");
     p->writableSchema = 0;
-    /* Set writable_schema=ON since doing so forces SQLite to initialize
-    ** as much of the schema as it can even if the sqlite_master table is
-    ** corrupt. */
-    sqlite3_exec(p->db, "SAVEPOINT dump; PRAGMA writable_schema=ON", 0, 0, 0);
+    if( ShellHasFlag(p, SHFLG_RecoveryMode) ){
+      /* Set writable_schema=ON since doing so forces SQLite to initialize
+      ** as much of the schema as it can even if the sqlite_master table is
+      ** corrupt. */
+      sqlite3_exec(p->db, "SAVEPOINT dump; PRAGMA writable_schema=ON", 0, 0, 0);
+    }
     p->nErr = 0;
     if( zLike==0 ){
       run_schema_dump_query(p,
@@ -4636,8 +4653,10 @@ static int do_meta_command(char *zLine, ShellState *p){
       raw_printf(p->out, "PRAGMA writable_schema=OFF;\n");
       p->writableSchema = 0;
     }
-    sqlite3_exec(p->db, "PRAGMA writable_schema=OFF;", 0, 0, 0);
-    sqlite3_exec(p->db, "RELEASE dump;", 0, 0, 0);
+    if( ShellHasFlag(p, SHFLG_RecoveryMode) ){
+      sqlite3_exec(p->db, "PRAGMA writable_schema=OFF;", 0, 0, 0);
+      sqlite3_exec(p->db, "RELEASE dump;", 0, 0, 0);
+    }
     raw_printf(p->out, p->nErr ? "ROLLBACK; -- due to errors\n" : "COMMIT;\n");
   }else