Make sure that the transitive constraint optimization does not cause

WHERE clause terms to be disabled prematurely.  We are unable to find a test
case that fails because of this, but it seems prudent to make this
preventative change nevertheless.

FossilOrigin-Name: d6e361d7fb8013d616af91ef2c10038c97d1be5f

manifest

@@ -1,5 +1,5 @@
-C Combine\sthe\sFuncDef.iPrefEnc\sand\sFuncDef.flags\sfields\sinto\sa\ssingle\nnew\sFuncDef.funcFlags\sfield.
-D 2013-09-06T13:10:12.385
+C Make\ssure\sthat\sthe\stransitive\sconstraint\soptimization\sdoes\snot\scause\nWHERE\sclause\sterms\sto\sbe\sdisabled\sprematurely.\s\sWe\sare\sunable\sto\sfind\sa\stest\ncase\sthat\sfails\sbecause\sof\sthis,\sbut\sit\sseems\sprudent\sto\smake\sthis\npreventative\schange\snevertheless.
+D 2013-09-09T19:37:46.167
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in 5e41da95d92656a5004b03d3576e8b226858a28e
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -290,7 +290,7 @@ F src/vtab.c 5a423b042eb1402ef77697d03d6a67378d97bc8d
 F src/wal.c 7dc3966ef98b74422267e7e6e46e07ff6c6eb1b4
 F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
 F src/walker.c 4fa43583d0a84b48f93b1e88f11adf2065be4e73
-F src/where.c 06c249a5137575ecf4d527e5a1dadb1087e4375c
+F src/where.c b5d59b899b85aa03800905ecdc0a17565d51a6ab
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
 F test/aggnested.test 45c0201e28045ad38a530b5a144b73cd4aa2cfd6
@@ -1111,7 +1111,7 @@ F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh fbc018d67fd7395f440c28f33ef0f94420226381
 F tool/wherecosttest.c f407dc4c79786982a475261866a161cd007947ae
 F tool/win/sqlite.vsix 97894c2790eda7b5bce3cc79cb2a8ec2fde9b3ac
-P a99a53b81e29c9514b85318bea028d1667e5f760
-R 8c10a6011eb52c6098e833ca515e6c77
+P 97b10e66e98e84755aa577f8da017bf1aea2056c
+R 73b0244a1b138f6550e626804843b7d8
 U drh
-Z c7e49c79214a66374f550dcdb7a70012
+Z 85372a45ca54a00c15dc226dffaae301

manifest.uuid

@@ -1 +1 @@
-97b10e66e98e84755aa577f8da017bf1aea2056c
+d6e361d7fb8013d616af91ef2c10038c97d1be5f

src/where.c

@@ -106,6 +106,7 @@ struct WhereLevel {
     Index *pCovidx;       /* Possible covering index for WHERE_MULTI_OR */
   } u;
   struct WhereLoop *pWLoop;  /* The selected WhereLoop object */
+  Bitmask notReady;          /* FROM entries not usable at this level */
 };
 
 /*
@@ -2799,6 +2800,7 @@ static void disableTerm(WhereLevel *pLevel, WhereTerm *pTerm){
   if( pTerm
       && (pTerm->wtFlags & TERM_CODED)==0
       && (pLevel->iLeftJoin==0 || ExprHasProperty(pTerm->pExpr, EP_FromJoin))
+      && (pLevel->notReady & pTerm->prereqAll)==0
   ){
     pTerm->wtFlags |= TERM_CODED;
     if( pTerm->iParent>=0 ){
@@ -3224,7 +3226,6 @@ static Bitmask codeOneLoopStart(
   int addrCont;                   /* Jump here to continue with next cycle */
   int iRowidReg = 0;        /* Rowid is stored in this register, if not zero */
   int iReleaseReg = 0;      /* Temp register to free before returning */
-  Bitmask newNotReady;      /* Return value */
 
   pParse = pWInfo->pParse;
   v = pParse->pVdbe;
@@ -3234,6 +3235,7 @@ static Bitmask codeOneLoopStart(
   pLoop = pLevel->pWLoop;
   pTabItem = &pWInfo->pTabList->a[pLevel->iFrom];
   iCur = pTabItem->iCursor;
+  pLevel->notReady = notReady & ~getMask(&pWInfo->sMaskSet, iCur);
   bRev = (pWInfo->revMask>>iLevel)&1;
   omitTable = (pLoop->wsFlags & WHERE_IDX_ONLY)!=0 
            && (pWInfo->wctrlFlags & WHERE_FORCE_TABLE)==0;
@@ -3886,7 +3888,6 @@ static Bitmask codeOneLoopStart(
     pLevel->p2 = 1 + sqlite3VdbeAddOp2(v, aStart[bRev], iCur, addrBrk);
     pLevel->p5 = SQLITE_STMTSTATUS_FULLSCAN_STEP;
   }
-  newNotReady = notReady & ~getMask(&pWInfo->sMaskSet, iCur);
 
   /* Insert code to test every subexpression that can be completely
   ** computed using the current set of tables.
@@ -3896,7 +3897,7 @@ static Bitmask codeOneLoopStart(
     testcase( pTerm->wtFlags & TERM_VIRTUAL );
     testcase( pTerm->wtFlags & TERM_CODED );
     if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
-    if( (pTerm->prereqAll & newNotReady)!=0 ){
+    if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
       testcase( pWInfo->untestedTerms==0
                && (pWInfo->wctrlFlags & WHERE_ONETABLE_ONLY)!=0 );
       pWInfo->untestedTerms = 1;
@@ -3928,7 +3929,7 @@ static Bitmask codeOneLoopStart(
     if( pLevel->iLeftJoin ) continue;
     pE = pTerm->pExpr;
     assert( !ExprHasProperty(pE, EP_FromJoin) );
-    assert( (pTerm->prereqRight & newNotReady)!=0 );
+    assert( (pTerm->prereqRight & pLevel->notReady)!=0 );
     pAlt = findTerm(pWC, iCur, pTerm->u.leftColumn, notReady, WO_EQ|WO_IN, 0);
     if( pAlt==0 ) continue;
     if( pAlt->wtFlags & (TERM_CODED) ) continue;
@@ -3956,7 +3957,7 @@ static Bitmask codeOneLoopStart(
       testcase( pTerm->wtFlags & TERM_VIRTUAL );
       testcase( pTerm->wtFlags & TERM_CODED );
       if( pTerm->wtFlags & (TERM_VIRTUAL|TERM_CODED) ) continue;
-      if( (pTerm->prereqAll & newNotReady)!=0 ){
+      if( (pTerm->prereqAll & pLevel->notReady)!=0 ){
         assert( pWInfo->untestedTerms );
         continue;
       }
@@ -3967,7 +3968,7 @@ static Bitmask codeOneLoopStart(
   }
   sqlite3ReleaseTempReg(pParse, iReleaseReg);
 
-  return newNotReady;
+  return pLevel->notReady;
 }
 
 #ifdef WHERETRACE_ENABLED