Minor enhancements to comments and clarification of the code.

FossilOrigin-Name: cbec30d0c49a3f618c3df3ae0ca3d651b48841c2

manifest

@@ -1,5 +1,5 @@
-C Add\sa\smissing\sVdbeCoverage()\smacro\son\san\sOP_Found\sopcode\sadded\sin\sthe\sprevious\ncheck-in.
+C Minor\senhancements\sto\scomments\sand\sclarification\sof\sthe\scode.
-D 2014-05-26T20:25:34.589
+D 2014-05-26T22:01:00.008
 F Makefile.arm-wince-mingw32ce-gcc d6df77f1f48d690bd73162294bbba7f59507c72f
 F Makefile.in dd2b1aba364ff9b05de41086f74407f285c57670
 F Makefile.linux-gcc 91d710bdc4998cb015f39edf3cb314ec4f4d7e23
@@ -294,7 +294,7 @@ F src/vtab.c 21b932841e51ebd7d075e2d0ad1415dce8d2d5fd
 F src/wal.c 76e7fc6de229bea8b30bb2539110f03a494dc3a8
 F src/wal.h df01efe09c5cb8c8e391ff1715cca294f89668a4
 F src/walker.c 11edb74d587bc87b33ca96a5173e3ec1b8389e45
-F src/where.c d46d73c76f48ede86e0e5bb112b2bcc91947bfaa
+F src/where.c b5719b11c414874826c676cf8c8455cb2939a30c
 F src/whereInt.h 6804c2e5010378568c2bb1350477537755296a46
 F test/8_3_names.test ebbb5cd36741350040fd28b432ceadf495be25b2
 F test/aggerror.test a867e273ef9e3d7919f03ef4f0e8c0d2767944f2
@@ -1173,7 +1173,7 @@ F tool/vdbe_profile.tcl 67746953071a9f8f2f668b73fe899074e2c6d8c1
 F tool/warnings-clang.sh f6aa929dc20ef1f856af04a730772f59283631d4
 F tool/warnings.sh d1a6de74685f360ab718efda6265994b99bbea01
 F tool/win/sqlite.vsix deb315d026cc8400325c5863eef847784a219a2f
-P 2c7e277bbebd5c93dec53d381d9737909d40d846
+P b4980a07e287480beddb2c6633c733520e05d074
-R 3707fb894adfd77b824ab9f7bdc17e79
+R 8f53ac145522e21d9a1c5059c77f2db7
 U drh
-Z 370b7f2e785b22f24333c303cca00bc0
+Z ad528aef359e7c77cf0a017e9208591c

manifest.uuid

@@ -1 +1 @@
-b4980a07e287480beddb2c6633c733520e05d074
+cbec30d0c49a3f618c3df3ae0ca3d651b48841c2

src/where.c

@@ -3293,6 +3293,10 @@ static Bitmask codeOneLoopStart(
     **
     **       B: <after the loop>
     **
+    ** Added 2014-05-26: If the table is a WITHOUT ROWID table, then
+    ** use an ephermeral index instead of a RowSet to record the primary
+    ** keys of the rows we have already seen.
+    **
     */
     WhereClause *pOrWc;    /* The OR-clause broken out into subterms */
     SrcList *pOrTab;       /* Shortened table list or OR-clause generation */
@@ -3340,7 +3344,8 @@ static Bitmask codeOneLoopStart(
     }
 
     /* Initialize the rowset register to contain NULL. An SQL NULL is 
-    ** equivalent to an empty rowset.
+    ** equivalent to an empty rowset.  Or, create an ephermeral index
+    ** capable of holding primary keys in the case of a WITHOUT ROWID.
     **
     ** Also initialize regReturn to contain the address of the instruction 
     ** immediately following the OP_Return at the bottom of the loop. This
@@ -3401,6 +3406,7 @@ static Bitmask codeOneLoopStart(
       if( pOrTerm->leftCursor==iCur || (pOrTerm->eOperator & WO_AND)!=0 ){
         WhereInfo *pSubWInfo;          /* Info for single OR-term scan */
         Expr *pOrExpr = pOrTerm->pExpr;
+        int j1 = 0;                    /* Address of jump operation */
         if( pAndExpr && !ExprHasProperty(pOrExpr, EP_FromJoin) ){
           pAndExpr->pLeft = pOrExpr;
           pOrExpr = pAndExpr;
@@ -3417,12 +3423,10 @@ static Bitmask codeOneLoopStart(
           );
           if( (pWInfo->wctrlFlags & WHERE_DUPLICATES_OK)==0 ){
             int r;
-            int addr;             /* Address just past Gosub coded below */
             int iSet = ((ii==pOrWc->nTerm-1)?-1:ii);
             if( HasRowid(pTab) ){
               r = sqlite3ExprCodeGetColumn(pParse, pTab, -1, iCur, regRowid, 0);
-              addr = sqlite3VdbeCurrentAddr(v)+2;
+              j1 = sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, 0, r,iSet);
-              sqlite3VdbeAddOp4Int(v, OP_RowSetTest, regRowset, addr, r, iSet);
               VdbeCoverage(v);
             }else{
               Index *pPk = sqlite3PrimaryKeyIndex(pTab);
@@ -3448,8 +3452,7 @@ static Bitmask codeOneLoopStart(
               ** need to insert the key into the temp table, as it will never 
               ** be tested for.  */ 
               if( iSet ){
-                addr = sqlite3VdbeCurrentAddr(v) + 2 + ((iSet>0) ? 2 : 0);
+                j1 = sqlite3VdbeAddOp4Int(v, OP_Found, regRowset, 0, r, nPk);
-                sqlite3VdbeAddOp4Int(v, OP_Found, regRowset, addr, r, nPk);
                 VdbeCoverage(v);
               }
               if( iSet>=0 ){
@@ -3461,10 +3464,9 @@ static Bitmask codeOneLoopStart(
               /* Release the array of temp registers */
               sqlite3ReleaseTempRange(pParse, r, nPk);
             }
-            assert( db->mallocFailed 
-                 || iSet==0 || addr==(sqlite3VdbeCurrentAddr(v)+1) );
           }
           sqlite3VdbeAddOp2(v, OP_Gosub, regReturn, iLoopBody);
+          if( j1 ) sqlite3VdbeJumpHere(v, j1);
 
           /* The pSubWInfo->untestedTerms flag means that this OR term
           ** contained one or more AND term from a notReady table.  The