diff --git a/manifest b/manifest
index 883ad2f581..b3dd4e89fa 100644
--- a/manifest
+++ b/manifest
@@ -1,5 +1,5 @@
-C Merge\slatest\schanges\sfrom\sthe\strunk\sinto\sthe\ssessions\sbranch.
-D 2011-09-14T19:41:44.795
+C Merge\sthe\slatest\strunk\schanges\sinto\sthe\ssessions\sbranch.
+D 2011-09-16T19:40:24.719
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in d314143fa6be24828021d3f583ad37d9afdce505
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -145,7 +145,7 @@ F src/complete.c dc1d136c0feee03c2f7550bafc0d29075e36deac
 F src/ctime.c e3132ec65240b2e2f3d50831021eac387f27584d
 F src/date.c a3c6842bad7ae632281811de112a8ba63ff08ab3
 F src/delete.c 614d6e012aa5b624e78f3b556243497825de196b
-F src/expr.c cbcd8c2f1588a9862291a081699854c5e1cb28ab
+F src/expr.c fd54c517869919c9b0b11dcadd43c66540ffa682
 F src/fault.c 160a0c015b6c2629d3899ed2daf63d75754a32bb
 F src/fkey.c 9f00ea98f6b360d477b5a78b5b59a1fbde82431c
 F src/func.c 59bb046d7e3df1ab512ac339ccb0a6f996a17cb7
@@ -191,11 +191,11 @@ F src/printf.c 585a36b6a963df832cfb69505afa3a34ed5ef8a1
 F src/random.c cd4a67b3953b88019f8cd4ccd81394a8ddfaba50
 F src/resolve.c 36368f44569208fa074e61f4dd0b6c4fb60ca2b4
 F src/rowset.c 69afa95a97c524ba6faf3805e717b5b7ae85a697
-F src/select.c bf7b7ea6befb483619da5f597b0864668b828c3c
+F src/select.c d9b7d20b0365f80761846f00ef3638d4b33eeaf2
 F src/shell.c bbe7818ff5bc8614105ceb81ad67b8bdc0b671dd
 F src/sqlite.h.in 355493ac9492746a0bbd17a4fd40911aa89b5a3a
 F src/sqlite3ext.h 1a1a4f784aa9c3b00edd287940197de52487cd93
-F src/sqliteInt.h 68a33c1d88051fae92a9528f198fbcaf3ddb3b39
+F src/sqliteInt.h 2c05edf4b8155bf4ef0775a9c30e4b57d7527af3
 F src/sqliteLimit.h 164b0e6749d31e0daa1a4589a169d31c0dec7b3d
 F src/status.c 7ac64842c86cec2fc1a1d0e5c16d3beb8ad332bf
 F src/table.c 2cd62736f845d82200acfa1287e33feb3c15d62e
@@ -250,12 +250,12 @@ F src/update.c 2d67e24d5a44d8b1c0839bf2ee0c391593e852bf
 F src/utf.c c53eb7404b3eb5c1cbb5655c6a7a0e0ce6bd50f0
 F src/util.c 06302ffd2b80408d4f6c7af71f7090e0cf8d8ff7
 F src/vacuum.c 05513dca036a1e7848fe18d5ed1265ac0b32365e
-F src/vdbe.c f03941d4126e2484a52652081a73f2e2e4d4eda1
-F src/vdbe.h a3308e58577f1586e4b0afb5e08b1fb6ac743d0d
+F src/vdbe.c a4d43779fd31b00cc7c6e1717e4b6cfacf499e66
+F src/vdbe.h 226d4bc726b3597c35be155a4342db290601d67c
 F src/vdbeInt.h 1400515b37a4863cdda4601abc0f76eca846c9f5
 F src/vdbeapi.c c969d467817ca90f99f3d3b46d115fbec08aeb4c
-F src/vdbeaux.c b09cc16325b4faad109fb3e59d393019d1600e55
-F src/vdbeblob.c fde0374afb0c512614aed191ac2683f6772d2b8f
+F src/vdbeaux.c 61701754a1528451ddb6e55e9d353e35ea940492
+F src/vdbeblob.c 11248c6362389569764682eb0f59ce910f3cc381
 F src/vdbemem.c 5e6effb96dd53d233361cbfaa3f0a43b9af689e9
 F src/vdbesort.c 468d43c057063e54da4f1988b38b4f46d60e7790
 F src/vdbetrace.c 5d0dc3d5fd54878cc8d6d28eb41deb8d5885b114
@@ -263,7 +263,7 @@ F src/vtab.c 901791a47318c0562cd0c676a2c6ff1bc530e582
 F src/wal.c 3154756177d6219e233d84291d5b05f4e06ff5e9
 F src/wal.h 66b40bd91bc29a5be1c88ddd1f5ade8f3f48728a
 F src/walker.c 3112bb3afe1d85dc52317cb1d752055e9a781f8f
-F src/where.c 7d09f4c1512affb60cc1190a4b33d121d4ce039a
+F src/where.c b641d399cfd8588d0e20d9790d1582b663a732a8
 F test/8_3_names.test 631ea964a3edb091cf73c3b540f6bcfdb36ce823
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/alias.test 4529fbc152f190268a15f9384a5651bbbabc9d87
@@ -700,6 +700,7 @@ F test/sqllimits1.test b1aae27cc98eceb845e7f7adf918561256e31298
 F test/stat.test 0997f6a57a35866b14111ed361ed8851ce7978ae
 F test/stmt.test 25d64e3dbf9a3ce89558667d7f39d966fe2a71b9
 F test/subquery.test b524f57c9574b2c0347045b4510ef795d4686796
+F test/subquery2.test edcad5c118f0531c2e21bf16a09bbb105252d4cd
 F test/subselect.test d24fd8757daf97dafd2e889c73ea4c4272dcf4e4
 F test/substr.test 18f57c4ca8a598805c4d64e304c418734d843c1a
 F test/superlock.test 5d7a4954b0059c903f82c7b67867bc5451a7c082
@@ -728,7 +729,7 @@ F test/tkt-02a8e81d44.test 58494de77be2cf249228ada3f313fa399821c6ab
 F test/tkt-26ff0c2d1e.test 888324e751512972c6e0d1a09df740d8f5aaf660
 F test/tkt-2d1a5c67d.test b028a811049eb472cb2d3a43fc8ce4f6894eebda
 F test/tkt-2ea2425d34.test 1cf13e6f75d149b3209a0cb32927a82d3d79fb28
-F test/tkt-31338dca7e.test 5741cd48de500347a437ba1be58c8335e83c5a5e
+F test/tkt-31338dca7e.test 1f714c14b6682c5db715e0bda347926a3456f7a9
 F test/tkt-313723c356.test c47f8a9330523e6f35698bf4489bcb29609b53ac
 F test/tkt-38cb5df375.test 9e9b19857dba0896a8efdaf334d405ba423492f2
 F test/tkt-3998683a16.test 6d1d04d551ed1704eb3396ca87bb9ccc8c5c1eb7
@@ -963,7 +964,7 @@ F tool/showjournal.c b62cecaab86a4053d944c276bb5232e4d17ece02
 F tool/showwal.c f09e5a80a293919290ec85a6a37c85a5ddcf37d9
 F tool/soak1.tcl 8d407956e1a45b485a8e072470a3e629a27037fe
 F tool/space_used.tcl f714c41a59e326b8b9042f415b628b561bafa06b
-F tool/spaceanal.tcl 1ee4df4e190675ba67b8c60cf304496d0021cfb4
+F tool/spaceanal.tcl fe02dede3d29ef0fefcf80a685644fdf4d9a768e
 F tool/speedtest.tcl 06c76698485ccf597b9e7dbb1ac70706eb873355
 F tool/speedtest16.c c8a9c793df96db7e4933f0852abb7a03d48f2e81
 F tool/speedtest2.tcl ee2149167303ba8e95af97873c575c3e0fab58ff
@@ -974,7 +975,7 @@ F tool/symbols.sh caaf6ccc7300fd43353318b44524853e222557d5
 F tool/tostr.awk e75472c2f98dd76e06b8c9c1367f4ab07e122d06
 F tool/vdbe-compress.tcl d70ea6d8a19e3571d7ab8c9b75cba86d1173ff0f
 F tool/warnings.sh b7fdb2cc525f5ef4fa43c80e771636dd3690f9d2
-P eb036d6f81e15bac013316bf5b1b2ba3e0bd4605 3035dc1c7398791d550f4c02774ef7f961b4bb02
-R 807d1da65636d94548ad55811c85e6a7
-U dan
-Z e140cc97ae2304f1c705299d75477c59
+P c00e45ede7cbf71a3a6d1ccad0b9275010ca8493 cf51ef8ab8a610ddf64f66970dd689fe1df405b8
+R 8f9c10e95fc4061078755c289f7e07d0
+U drh
+Z 423f374ece1297d22d3fad8417996b4a
diff --git a/manifest.uuid b/manifest.uuid
index 39610efda7..a912068f8e 100644
--- a/manifest.uuid
+++ b/manifest.uuid
@@ -1 +1 @@
-c00e45ede7cbf71a3a6d1ccad0b9275010ca8493
\ No newline at end of file
+5efb02949dbeabccfe1d848d275529f03f3dfc84
\ No newline at end of file
diff --git a/src/expr.c b/src/expr.c
index ab218078db..6fd08b27f1 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -901,7 +901,8 @@ SrcList *sqlite3SrcListDup(sqlite3 *db, SrcList *p, int flags){
     pNewItem->zAlias = sqlite3DbStrDup(db, pOldItem->zAlias);
     pNewItem->jointype = pOldItem->jointype;
     pNewItem->iCursor = pOldItem->iCursor;
-    pNewItem->isPopulated = pOldItem->isPopulated;
+    pNewItem->addrFillSub = pOldItem->addrFillSub;
+    pNewItem->regReturn = pOldItem->regReturn;
     pNewItem->isCorrelated = pOldItem->isCorrelated;
     pNewItem->zIndex = sqlite3DbStrDup(db, pOldItem->zIndex);
     pNewItem->notIndexed = pOldItem->notIndexed;
@@ -1461,8 +1462,7 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
       int iMem = ++pParse->nMem;
       int iAddr;
 
-      iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
-      sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
+      iAddr = sqlite3VdbeAddOp1(v, OP_Once, iMem);
 
       sqlite3OpenTable(pParse, iTab, iDb, pTab, OP_OpenRead);
       eType = IN_INDEX_ROWID;
@@ -1493,8 +1493,7 @@ int sqlite3FindInIndex(Parse *pParse, Expr *pX, int *prNotFound){
           char *pKey;
   
           pKey = (char *)sqlite3IndexKeyinfo(pParse, pIdx);
-          iAddr = sqlite3VdbeAddOp1(v, OP_If, iMem);
-          sqlite3VdbeAddOp2(v, OP_Integer, 1, iMem);
+          iAddr = sqlite3VdbeAddOp1(v, OP_Once, iMem);
   
           sqlite3VdbeAddOp4(v, OP_OpenRead, iTab, pIdx->tnum, iDb,
                                pKey,P4_KEYINFO_HANDOFF);
@@ -1579,6 +1578,7 @@ int sqlite3CodeSubselect(
   int rReg = 0;                           /* Register storing resulting */
   Vdbe *v = sqlite3GetVdbe(pParse);
   if( NEVER(v==0) ) return 0;
+  assert( sqlite3VdbeCurrentAddr(v)>0 );
   sqlite3ExprCachePush(pParse);
 
   /* This code must be run in its entirety every time it is encountered
@@ -1593,8 +1593,7 @@ int sqlite3CodeSubselect(
   */
   if( !ExprHasAnyProperty(pExpr, EP_VarSelect) && !pParse->pTriggerTab ){
     int mem = ++pParse->nMem;
-    sqlite3VdbeAddOp1(v, OP_If, mem);
-    testAddr = sqlite3VdbeAddOp2(v, OP_Integer, 1, mem);
+    testAddr = sqlite3VdbeAddOp1(v, OP_Once, mem);
     assert( testAddr>0 || pParse->db->mallocFailed );
   }
 
@@ -1694,7 +1693,7 @@ int sqlite3CodeSubselect(
           ** expression we need to rerun this code each time.
           */
           if( testAddr && !sqlite3ExprIsConstant(pE2) ){
-            sqlite3VdbeChangeToNoop(v, testAddr-1, 2);
+            sqlite3VdbeChangeToNoop(v, testAddr);
             testAddr = 0;
           }
 
@@ -1765,7 +1764,7 @@ int sqlite3CodeSubselect(
   }
 
   if( testAddr ){
-    sqlite3VdbeJumpHere(v, testAddr-1);
+    sqlite3VdbeJumpHere(v, testAddr);
   }
   sqlite3ExprCachePop(pParse, 1);
 
diff --git a/src/select.c b/src/select.c
index a8ea08a781..89c6b251c3 100644
--- a/src/select.c
+++ b/src/select.c
@@ -89,6 +89,8 @@ Select *sqlite3SelectNew(
     clearSelect(db, pNew);
     if( pNew!=&standin ) sqlite3DbFree(db, pNew);
     pNew = 0;
+  }else{
+    assert( pNew->pSrc!=0 || pParse->nErr>0 );
   }
   return pNew;
 }
@@ -3801,7 +3803,11 @@ int sqlite3Select(
     Select *pSub = pItem->pSelect;
     int isAggSub;
 
-    if( pSub==0 || pItem->isPopulated ) continue;
+    if( pSub==0 ) continue;
+    if( pItem->addrFillSub ){
+      sqlite3VdbeAddOp2(v, OP_Gosub, pItem->regReturn, pItem->addrFillSub);
+      continue;
+    }
 
     /* Increment Parse.nHeight by the height of the largest expression
     ** tree refered to by this, the parent select. The child select
@@ -3812,21 +3818,44 @@ int sqlite3Select(
     */
     pParse->nHeight += sqlite3SelectExprHeight(p);
 
-    /* Check to see if the subquery can be absorbed into the parent. */
     isAggSub = (pSub->selFlags & SF_Aggregate)!=0;
     if( flattenSubquery(pParse, p, i, isAgg, isAggSub) ){
+      /* This subquery can be absorbed into its parent. */
       if( isAggSub ){
         isAgg = 1;
         p->selFlags |= SF_Aggregate;
       }
       i = -1;
     }else{
+      /* Generate a subroutine that will fill an ephemeral table with
+      ** the content of this subquery.  pItem->addrFillSub will point
+      ** to the address of the generated subroutine.  pItem->regReturn
+      ** is a register allocated to hold the subroutine return address
+      */
+      int topAddr;
+      int onceAddr = 0;
+      int retAddr;
+      assert( pItem->addrFillSub==0 );
+      pItem->regReturn = ++pParse->nMem;
+      topAddr = sqlite3VdbeAddOp2(v, OP_Integer, 0, pItem->regReturn);
+      pItem->addrFillSub = topAddr+1;
+      VdbeNoopComment((v, "materialize %s", pItem->pTab->zName));
+      if( pItem->isCorrelated==0 && pParse->pTriggerTab==0 ){
+        /* If the subquery is no correlated and if we are not inside of
+        ** a trigger, then we only need to compute the value of the subquery
+        ** once. */
+        int regOnce = ++pParse->nMem;
+        onceAddr = sqlite3VdbeAddOp1(v, OP_Once, regOnce);
+      }
       sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
-      assert( pItem->isPopulated==0 );
       explainSetInteger(pItem->iSelectId, (u8)pParse->iNextSelectId);
       sqlite3Select(pParse, pSub, &dest);
-      pItem->isPopulated = 1;
       pItem->pTab->nRowEst = (unsigned)pSub->nSelectRow;
+      if( onceAddr ) sqlite3VdbeJumpHere(v, onceAddr);
+      retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn);
+      VdbeComment((v, "end %s", pItem->pTab->zName));
+      sqlite3VdbeChangeP1(v, topAddr, retAddr);
+
     }
     if( /*pParse->nErr ||*/ db->mallocFailed ){
       goto select_end;
@@ -3967,7 +3996,7 @@ int sqlite3Select(
     ** into an OP_Noop.
     */
     if( addrSortIndex>=0 && pOrderBy==0 ){
-      sqlite3VdbeChangeToNoop(v, addrSortIndex, 1);
+      sqlite3VdbeChangeToNoop(v, addrSortIndex);
       p->addrOpenEphm[2] = -1;
     }
 
@@ -4250,7 +4279,7 @@ int sqlite3Select(
         sqlite3VdbeAddOp2(v, OP_SorterNext, sAggInfo.sortingIdx, addrTopOfLoop);
       }else{
         sqlite3WhereEnd(pWInfo);
-        sqlite3VdbeChangeToNoop(v, addrSortingIdx, 1);
+        sqlite3VdbeChangeToNoop(v, addrSortingIdx);
       }
 
       /* Output the final row of result
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 390e40e31b..b1cc524377 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -1860,7 +1860,8 @@ struct SrcList {
     char *zAlias;     /* The "B" part of a "A AS B" phrase.  zName is the "A" */
     Table *pTab;      /* An SQL table corresponding to zName */
     Select *pSelect;  /* A SELECT statement used in place of a table name */
-    u8 isPopulated;   /* Temporary table associated with SELECT is populated */
+    int addrFillSub;  /* Address of subroutine to manifest a subquery */
+    int regReturn;    /* Register holding return address of addrFillSub */
     u8 jointype;      /* Type of join between this able and the previous */
     u8 notIndexed;    /* True if there is a NOT INDEXED clause */
     u8 isCorrelated;  /* True if sub-query is correlated */
diff --git a/src/vdbe.c b/src/vdbe.c
index b6bf463047..1822cea785 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -2031,6 +2031,16 @@ case OP_BitNot: {             /* same as TK_BITNOT, in1, out2 */
   break;
 }
 
+/* Opcode: Once P1 P2 * * *
+**
+** Jump to P2 if the value in register P1 is a not null or zero.  If
+** the value is NULL or zero, fall through and change the P1 register
+** to an integer 1.
+**
+** When P1 is not used otherwise in a program, this opcode falls through
+** once and jumps on all subsequent invocations.  It is the equivalent
+** of "OP_If P1 P2", followed by "OP_Integer 1 P1".
+*/
 /* Opcode: If P1 P2 P3 * *
 **
 ** Jump to P2 if the value in register P1 is true.  The value
@@ -2043,6 +2053,7 @@ case OP_BitNot: {             /* same as TK_BITNOT, in1, out2 */
 ** is considered true if it has a numeric value of zero.  If the value
 ** in P1 is NULL then take the jump if P3 is true.
 */
+case OP_Once:               /* jump, in1 */
 case OP_If:                 /* jump, in1 */
 case OP_IfNot: {            /* jump, in1 */
   int c;
@@ -2059,6 +2070,12 @@ case OP_IfNot: {            /* jump, in1 */
   }
   if( c ){
     pc = pOp->p2-1;
+  }else if( pOp->opcode==OP_Once ){
+    assert( (pIn1->flags & (MEM_Agg|MEM_Dyn|MEM_RowSet|MEM_Frame))==0 );
+    memAboutToChange(p, pIn1);
+    pIn1->flags = MEM_Int;
+    pIn1->u.i = 1;
+    REGISTER_TRACE(pOp->p1, pIn1);
   }
   break;
 }
diff --git a/src/vdbe.h b/src/vdbe.h
index 9332b9851d..990cb1790e 100644
--- a/src/vdbe.h
+++ b/src/vdbe.h
@@ -182,7 +182,7 @@ void sqlite3VdbeChangeP2(Vdbe*, u32 addr, int P2);
 void sqlite3VdbeChangeP3(Vdbe*, u32 addr, int P3);
 void sqlite3VdbeChangeP5(Vdbe*, u8 P5);
 void sqlite3VdbeJumpHere(Vdbe*, int addr);
-void sqlite3VdbeChangeToNoop(Vdbe*, int addr, int N);
+void sqlite3VdbeChangeToNoop(Vdbe*, int addr);
 void sqlite3VdbeChangeP4(Vdbe*, int addr, const char *zP4, int N);
 void sqlite3VdbeUsesBtree(Vdbe*, int);
 VdbeOp *sqlite3VdbeGetOp(Vdbe*, int);
diff --git a/src/vdbeaux.c b/src/vdbeaux.c
index b7239bb684..7092724403 100644
--- a/src/vdbeaux.c
+++ b/src/vdbeaux.c
@@ -671,18 +671,15 @@ void sqlite3VdbeLinkSubProgram(Vdbe *pVdbe, SubProgram *p){
 }
 
 /*
-** Change N opcodes starting at addr to No-ops.
+** Change the opcode at addr into OP_Noop
 */
-void sqlite3VdbeChangeToNoop(Vdbe *p, int addr, int N){
+void sqlite3VdbeChangeToNoop(Vdbe *p, int addr){
   if( p->aOp ){
     VdbeOp *pOp = &p->aOp[addr];
     sqlite3 *db = p->db;
-    while( N-- ){
-      freeP4(db, pOp->p4type, pOp->p4.p);
-      memset(pOp, 0, sizeof(pOp[0]));
-      pOp->opcode = OP_Noop;
-      pOp++;
-    }
+    freeP4(db, pOp->p4type, pOp->p4.p);
+    memset(pOp, 0, sizeof(pOp[0]));
+    pOp->opcode = OP_Noop;
   }
 }
 
diff --git a/src/vdbeblob.c b/src/vdbeblob.c
index 2f37ad933b..995c08d166 100644
--- a/src/vdbeblob.c
+++ b/src/vdbeblob.c
@@ -277,7 +277,7 @@ int sqlite3_blob_open(
 
       /* Configure the OP_TableLock instruction */
 #ifdef SQLITE_OMIT_SHARED_CACHE
-      sqlite3VdbeChangeToNoop(v, 2, 1);
+      sqlite3VdbeChangeToNoop(v, 2);
 #else
       sqlite3VdbeChangeP1(v, 2, iDb);
       sqlite3VdbeChangeP2(v, 2, pTab->tnum);
@@ -287,7 +287,7 @@ int sqlite3_blob_open(
 
       /* Remove either the OP_OpenWrite or OpenRead. Set the P2 
       ** parameter of the other to pTab->tnum.  */
-      sqlite3VdbeChangeToNoop(v, 4 - flags, 1);
+      sqlite3VdbeChangeToNoop(v, 4 - flags);
       sqlite3VdbeChangeP2(v, 3 + flags, pTab->tnum);
       sqlite3VdbeChangeP3(v, 3 + flags, iDb);
 
diff --git a/src/where.c b/src/where.c
index 21fb7f45f4..fd7da6274d 100644
--- a/src/where.c
+++ b/src/where.c
@@ -467,11 +467,19 @@ static Bitmask exprListTableUsage(WhereMaskSet *pMaskSet, ExprList *pList){
 static Bitmask exprSelectTableUsage(WhereMaskSet *pMaskSet, Select *pS){
   Bitmask mask = 0;
   while( pS ){
+    SrcList *pSrc = pS->pSrc;
     mask |= exprListTableUsage(pMaskSet, pS->pEList);
     mask |= exprListTableUsage(pMaskSet, pS->pGroupBy);
     mask |= exprListTableUsage(pMaskSet, pS->pOrderBy);
     mask |= exprTableUsage(pMaskSet, pS->pWhere);
     mask |= exprTableUsage(pMaskSet, pS->pHaving);
+    if( ALWAYS(pSrc!=0) ){
+      int i;
+      for(i=0; i<pSrc->nSrc; i++){
+        mask |= exprSelectTableUsage(pMaskSet, pSrc->a[i].pSelect);
+        mask |= exprTableUsage(pMaskSet, pSrc->a[i].pOn);
+      }
+    }
     pS = pS->pPrior;
   }
   return mask;
@@ -1994,8 +2002,7 @@ static void constructAutomaticIndex(
   v = pParse->pVdbe;
   assert( v!=0 );
   regIsInit = ++pParse->nMem;
-  addrInit = sqlite3VdbeAddOp1(v, OP_If, regIsInit);
-  sqlite3VdbeAddOp2(v, OP_Integer, 1, regIsInit);
+  addrInit = sqlite3VdbeAddOp1(v, OP_Once, regIsInit);
 
   /* Count the number of columns that will be added to the index
   ** and used to match WHERE clause constraints */
diff --git a/test/subquery2.test b/test/subquery2.test
new file mode 100644
index 0000000000..04200046f9
--- /dev/null
+++ b/test/subquery2.test
@@ -0,0 +1,86 @@
+# 2011 September 16
+#
+# 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 implements regression tests for SQLite library.  The
+# focus of this script is testing correlated subqueries
+#
+#
+
+set testdir [file dirname $argv0]
+source $testdir/tester.tcl
+
+ifcapable !subquery {
+  finish_test
+  return
+}
+
+do_test subquery2-1.1 {
+  execsql {
+    BEGIN;
+    CREATE TABLE t1(a,b);
+    INSERT INTO t1 VALUES(1,2);
+    INSERT INTO t1 VALUES(3,4);
+    INSERT INTO t1 VALUES(5,6);
+    INSERT INTO t1 VALUES(7,8);
+    CREATE TABLE t2(c,d);
+    INSERT INTO t2 VALUES(1,1);
+    INSERT INTO t2 VALUES(3,9);
+    INSERT INTO t2 VALUES(5,25);
+    INSERT INTO t2 VALUES(7,49);
+    CREATE TABLE t3(e,f);
+    INSERT INTO t3 VALUES(1,1);
+    INSERT INTO t3 VALUES(3,27);
+    INSERT INTO t3 VALUES(5,125);
+    INSERT INTO t3 VALUES(7,343);
+    COMMIT;
+  }
+  execsql {
+    SELECT a FROM t1
+     WHERE b IN (SELECT x+1 FROM (SELECT DISTINCT f/(a*a) AS x FROM t3));
+  }
+} {1 3 5 7}
+do_test subquery2-1.2 {
+  execsql {
+    CREATE INDEX t1b ON t1(b);
+    SELECT a FROM t1
+     WHERE b IN (SELECT x+1 FROM (SELECT DISTINCT f/(a*a) AS x FROM t3));
+  }
+} {1 3 5 7}
+
+do_test subquery2-1.11 {
+  execsql {
+    SELECT a FROM t1
+     WHERE +b=(SELECT x+1 FROM (SELECT DISTINCT f/(a*a) AS x FROM t3));
+  }
+} {1}
+do_test subquery2-1.12 {
+  execsql {
+    SELECT a FROM t1
+     WHERE b=(SELECT x+1 FROM (SELECT DISTINCT f/(a*a) AS x FROM t3));
+  }
+} {1}
+
+do_test subquery2-1.21 {
+  execsql {
+    SELECT a FROM t1
+     WHERE +b=(SELECT x+1 FROM 
+                 (SELECT DISTINCT f/d AS x FROM t2 JOIN t3 ON d*a=f))
+  }
+} {1 3 5 7}
+do_test subquery2-1.22 {
+  execsql {
+    SELECT a FROM t1
+     WHERE b=(SELECT x+1 FROM 
+                 (SELECT DISTINCT f/d AS x FROM t2 JOIN t3 ON d*a=f))
+  }
+} {1 3 5 7}
+
+
+finish_test
diff --git a/test/tkt-31338dca7e.test b/test/tkt-31338dca7e.test
index 3f66816d64..9423c684e9 100644
--- a/test/tkt-31338dca7e.test
+++ b/test/tkt-31338dca7e.test
@@ -74,4 +74,105 @@ do_test tkt-31338-2.2 {
 } {111 222 222 333 888 333 444 444 555 888 333 444 444 555 999}
 
 
+# Ticket [2c2de252666662f5459904fc33a9f2956cbff23c]
+#
+do_test tkt-31338-3.1 {
+  foreach x [db eval {SELECT name FROM sqlite_master WHERE type='table'}] {
+     db eval "DROP TABLE $x"
+  }
+  db eval {
+    CREATE TABLE t1(a,b,c,d);
+    CREATE TABLE t2(e,f);
+    INSERT INTO t1 VALUES(1,2,3,4);
+    INSERT INTO t2 VALUES(10,-8);
+    CREATE INDEX t1a ON t1(a);
+    CREATE INDEX t1b ON t1(b);
+    CREATE TABLE t3(g);
+    INSERT INTO t3 VALUES(4);
+    CREATE TABLE t4(h);
+    INSERT INTO t4 VALUES(5);
+    
+    SELECT * FROM t3 LEFT JOIN t1 ON d=g LEFT JOIN t4 ON c=h
+     WHERE (a=1 AND h=4)
+         OR (b IN (
+               SELECT x FROM (SELECT e+f AS x, e FROM t2 ORDER BY 1 LIMIT 2)
+               GROUP BY e
+            ));
+  }    
+} {4 1 2 3 4 {}}
+do_test tkt-31338-3.2 {
+  db eval {    
+    SELECT * FROM t3 LEFT JOIN t1 ON d=g LEFT JOIN t4 ON c=h
+     WHERE (a=1 AND h=4)
+         OR (b=2 AND b NOT IN (
+               SELECT x+1 FROM (SELECT e+f AS x, e FROM t2 ORDER BY 1 LIMIT 2)
+               GROUP BY e
+            ));
+  }    
+} {4 1 2 3 4 {}}
+do_test tkt-31338-3.3 {
+  db eval {    
+    SELECT * FROM t3 LEFT JOIN t1 ON d=g LEFT JOIN t4 ON c=h
+     WHERE (+a=1 AND h=4)
+         OR (b IN (
+               SELECT x FROM (SELECT e+f AS x, e FROM t2 ORDER BY 1 LIMIT 2)
+               GROUP BY e
+            ));
+  }    
+} {4 1 2 3 4 {}}
+do_test tkt-31338-3.4 {
+  db eval {    
+    SELECT * FROM t3 LEFT JOIN t1 ON d=g LEFT JOIN t4 ON c=h
+     WHERE (a=1 AND h=4)
+         OR (+b IN (
+               SELECT x FROM (SELECT e+f AS x, e FROM t2 ORDER BY 1 LIMIT 2)
+               GROUP BY e
+            ));
+  }    
+} {4 1 2 3 4 {}}
+
+do_test tkt-31338-3.5 {
+  db eval {
+    CREATE TABLE t5(a,b,c,d,e,f);
+    CREATE TABLE t6(g,h);
+    CREATE TRIGGER t6r AFTER INSERT ON t6 BEGIN
+      INSERT INTO t5    
+        SELECT * FROM t3 LEFT JOIN t1 ON d=g LEFT JOIN t4 ON c=h
+         WHERE (a=1 AND h=4)
+            OR (b IN (
+               SELECT x FROM (SELECT e+f AS x, e FROM t2 ORDER BY 1 LIMIT 2)
+               GROUP BY e
+            ));
+    END;
+    INSERT INTO t6 VALUES(88,99);
+    SELECT * FROM t5;
+  }    
+} {4 1 2 3 4 {}}
+
+do_test tkt-31338-3.6 {
+  db eval {    
+    INSERT INTO t1 VALUES(2,4,3,4);
+    INSERT INTO t1 VALUES(99,101,3,4);
+    INSERT INTO t1 VALUES(98,97,3,4);
+    SELECT * FROM t3 LEFT JOIN t1 ON d=g LEFT JOIN t4 ON c=h
+     WHERE (a=1 AND h=4)
+         OR (b IN (
+               SELECT x+a FROM (SELECT e+f AS x, e FROM t2 ORDER BY 1 LIMIT 2)
+               GROUP BY e
+            ));
+  }    
+} {4 2 4 3 4 {} 4 99 101 3 4 {}}
+
+do_test tkt-31338-3.7 {
+  db eval {
+    SELECT * FROM t3 LEFT JOIN t1 ON d=g LEFT JOIN t4 ON c=h
+     WHERE (a=1 AND h=4)
+         OR (b IN (
+               SELECT x FROM (SELECT e+f+a AS x, e FROM t2 ORDER BY 1 LIMIT 2)
+               GROUP BY e
+            ));
+  }    
+} {4 2 4 3 4 {} 4 99 101 3 4 {}}
+
+
 finish_test
diff --git a/tool/spaceanal.tcl b/tool/spaceanal.tcl
index 13ab1af5f7..52e825b798 100644
--- a/tool/spaceanal.tcl
+++ b/tool/spaceanal.tcl
@@ -4,11 +4,14 @@
 #
 
 if {[catch {
+if {![info exists argv0]} {
+  set argv0 [file rootname [file tail [info nameofexecutable]]]
+}
 
 # Get the name of the database to analyze
 #
 #set argv $argv0
-if {[llength $argv]!=1} {
+if {![info exists argv] || [llength $argv]!=1} {
   puts stderr "Usage: $argv0 database-name"
   exit 1
 }
@@ -28,12 +31,12 @@ if {[file size $file_to_analyze]<512} {
 
 # Open the database
 #
-sqlite3 db [lindex $argv 0]
+sqlite3 db $file_to_analyze
 register_dbstat_vtab db
 
 set pageSize [db one {PRAGMA page_size}]
 
-#set DB [btree_open [lindex $argv 0] 1000 0]
+#set DB [btree_open $file_to_analyze 1000 0]
 
 # In-memory database for collecting statistics. This script loops through
 # the tables and indices in the database being analyzed, adding a row for each