1 files changed, 24 insertions, 12 deletions

diff --git a/src/select.c b/src/select.c
index beb5c1e3b..cab90eb01 100644
--- a/src/select.c
+++ b/src/select.c
@@ -1986,7 +1986,7 @@ int sqlite3ColumnsFromExprList(
     nCol = pEList->nExpr;
     aCol = sqlite3DbMallocZero(db, sizeof(aCol[0])*nCol);
     testcase( aCol==0 );
-    if( nCol>32767 ) nCol = 32767;
+    if( NEVER(nCol>32767) ) nCol = 32767;
   }else{
     nCol = 0;
     aCol = 0;
@@ -4039,6 +4039,7 @@ static int flattenSubquery(
     if( (p->selFlags & SF_Recursive) ) return 0;
 
     if( pSrc->nSrc>1 ){
+      if( pParse->nSelect>500 ) return 0;
       aCsrMap = sqlite3DbMallocZero(db, pParse->nTab*sizeof(int));
     }
   }
@@ -4115,6 +4116,7 @@ static int flattenSubquery(
     if( pNew==0 ){
       p->pPrior = pPrior;
     }else{
+      pNew->selId = ++pParse->nSelect;
       if( aCsrMap && db->mallocFailed==0 ){
         renumberCursors(pParse, pNew, iFrom, aCsrMap);
       }
@@ -5058,16 +5060,24 @@ static int resolveFromTermToCte(
     pSavedWith = pParse->pWith;
     pParse->pWith = pWith;
     if( pSel->selFlags & SF_Recursive ){
+      int rc;
       assert( pRecTerm!=0 );
       assert( (pRecTerm->selFlags & SF_Recursive)==0 );
       assert( pRecTerm->pNext!=0 );
       assert( (pRecTerm->pNext->selFlags & SF_Recursive)!=0 );
       assert( pRecTerm->pWith==0 );
       pRecTerm->pWith = pSel->pWith;
-      sqlite3WalkSelect(pWalker, pRecTerm);
+      rc = sqlite3WalkSelect(pWalker, pRecTerm);
       pRecTerm->pWith = 0;
+      if( rc ){
+        pParse->pWith = pSavedWith;
+        return 2;
+      }
     }else{
-      sqlite3WalkSelect(pWalker, pSel);
+      if( sqlite3WalkSelect(pWalker, pSel) ){
+        pParse->pWith = pSavedWith;
+        return 2;
+      }
     }
     pParse->pWith = pWith;
 
@@ -5772,7 +5782,7 @@ static void explainSimpleCount(
 ){
   if( pParse->explain==2 ){
     int bCover = (pIdx!=0 && (HasRowid(pTab) || !IsPrimaryKeyIndex(pIdx)));
-    sqlite3VdbeExplain(pParse, 0, "SCAN TABLE %s%s%s",
+    sqlite3VdbeExplain(pParse, 0, "SCAN %s%s%s",
         pTab->zName,
         bCover ? " USING COVERING INDEX " : "",
         bCover ? pIdx->zName : ""
@@ -6345,10 +6355,10 @@ int sqlite3Select(
      
       pItem->regReturn = ++pParse->nMem;
       sqlite3VdbeAddOp3(v, OP_InitCoroutine, pItem->regReturn, 0, addrTop);
-      VdbeComment((v, "%s", pItem->pTab->zName));
+      VdbeComment((v, "%!S", pItem));
       pItem->addrFillSub = addrTop;
       sqlite3SelectDestInit(&dest, SRT_Coroutine, pItem->regReturn);
-      ExplainQueryPlan((pParse, 1, "CO-ROUTINE %u", pSub->selId));
+      ExplainQueryPlan((pParse, 1, "CO-ROUTINE %!S", pItem));
       sqlite3Select(pParse, pSub, &dest);
       pItem->pTab->nRowLogEst = pSub->nSelectRow;
       pItem->fg.viaCoroutine = 1;
@@ -6376,7 +6386,9 @@ int sqlite3Select(
       sqlite3VdbeAddOp2(v, OP_OpenDup, pItem->iCursor, pPrior->iCursor);
       pSub->nSelectRow = pPrior->pSelect->nSelectRow;
     }else{
-      /* Generate a subroutine that will materialize the view. */
+      /* Materalize the view.  If the view is not correlated, generate a
+      ** subroutine to do the materialization so that subsequent uses of
+      ** the same view can reuse the materialization. */
       int topAddr;
       int onceAddr = 0;
       int retAddr;
@@ -6390,20 +6402,20 @@ int sqlite3Select(
         ** a trigger, then we only need to compute the value of the subquery
         ** once. */
         onceAddr = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v);
-        VdbeComment((v, "materialize \"%s\"", pItem->pTab->zName));
+        VdbeComment((v, "materialize %!S", pItem));
       }else{
-        VdbeNoopComment((v, "materialize \"%s\"", pItem->pTab->zName));
+        VdbeNoopComment((v, "materialize %!S", pItem));
       }
       sqlite3SelectDestInit(&dest, SRT_EphemTab, pItem->iCursor);
-      ExplainQueryPlan((pParse, 1, "MATERIALIZE %u", pSub->selId));
+      ExplainQueryPlan((pParse, 1, "MATERIALIZE %!S", pItem));
       sqlite3Select(pParse, pSub, &dest);
       pItem->pTab->nRowLogEst = pSub->nSelectRow;
       if( onceAddr ) sqlite3VdbeJumpHere(v, onceAddr);
       retAddr = sqlite3VdbeAddOp1(v, OP_Return, pItem->regReturn);
-      VdbeComment((v, "end %s", pItem->pTab->zName));
+      VdbeComment((v, "end %!S", pItem));
       sqlite3VdbeChangeP1(v, topAddr, retAddr);
       sqlite3ClearTempRegCache(pParse);
-      if( pItem->fg.isCte ){
+      if( pItem->fg.isCte && pItem->fg.isCorrelated==0 ){
         CteUse *pCteUse = pItem->u2.pCteUse;
         pCteUse->addrM9e = pItem->addrFillSub;
         pCteUse->regRtn = pItem->regReturn;