New assert() statements to protect the u1 and u2 unions of SrcList.

FossilOrigin-Name: 9b91fbcfcc14048f7d0755d47d9b7f9212fa2eaa6f3c04f417fa16c3a47943bf

5 files changed, 8 insertions, 2 deletions

diff --git a/src/build.c b/src/build.c
index 58762bf37..1bf082712 100644
--- a/src/build.c
+++ b/src/build.c
@@ -4927,6 +4927,7 @@ void sqlite3SrcListIndexedBy(Parse *pParse, SrcList *p, Token *pIndexedBy){
     }else{
       pItem->u1.zIndexedBy = sqlite3NameFromToken(pParse->db, pIndexedBy);
       pItem->fg.isIndexedBy = 1;
+      assert( pItem->fg.isCte==0 );  /* No collision on union u2 */
     }
   }
 }
diff --git a/src/delete.c b/src/delete.c
index 0debce3cb..e2b283ea4 100644
--- a/src/delete.c
+++ b/src/delete.c
@@ -210,6 +210,7 @@ Expr *sqlite3LimitWhere(
   pSelectSrc = sqlite3SrcListDup(db, pSrc, 0);
   pSrc->a[0].pTab = pTab;
   if( pSrc->a[0].fg.isIndexedBy ){
+    assert( pSrc->a[0].fg.isCte==0 );
     pSrc->a[0].u2.pIBIndex = 0;
     pSrc->a[0].fg.isIndexedBy = 0;
     sqlite3DbFree(db, pSrc->a[0].u1.zIndexedBy);
diff --git a/src/select.c b/src/select.c
index e846a0220..13ed20f6c 100644
--- a/src/select.c
+++ b/src/select.c
@@ -4995,6 +4995,7 @@ int sqlite3IndexedByLookup(Parse *pParse, SrcItem *pFrom){
     pParse->checkSchema = 1;
     return SQLITE_ERROR;
   }
+  assert( pFrom->fg.isCte==0 );
   pFrom->u2.pIBIndex = pIdx;
   return SQLITE_OK;
 }
@@ -5252,6 +5253,7 @@ static int resolveFromTermToCte(
     if( db->mallocFailed ) return 2;
     pFrom->pSelect->selFlags |= SF_CopyCte;
     assert( pFrom->pSelect );
+    assert( pFrom->fg.isIndexedBy==0 ); /* Prevent collision in union u2 */
     pFrom->fg.isCte = 1;
     pFrom->u2.pCteUse = pCteUse;
     pCteUse->nUse++;
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index 009742c4d..f51743168 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -2975,11 +2975,12 @@ struct ExprList {
     unsigned bSorterRef :1; /* Defer evaluation until after sorting */
     unsigned bNulls: 1;     /* True if explicit "NULLS FIRST/LAST" */
     union {
-      struct {
+      struct {             /* Used by any ExprList other than Parse.pConsExpr */
         u16 iOrderByCol;      /* For ORDER BY, column number in result set */
         u16 iAlias;           /* Index into Parse.aAlias[] for zName */
       } x;
-      int iConstExprReg;      /* Register in which Expr value is cached */
+      int iConstExprReg;   /* Register in which Expr value is cached. Used only
+                           ** by Parse.pConstExpr */
     } u;
   } a[1];                  /* One slot for each expression in the list */
 };
diff --git a/src/where.c b/src/where.c
index 7583f0563..4d1737660 100644
--- a/src/where.c
+++ b/src/where.c
@@ -3002,6 +3002,7 @@ static int whereLoopAddBtree(
   assert( !IsVirtual(pSrc->pTab) );
 
   if( pSrc->fg.isIndexedBy ){
+    assert( pSrc->fg.isCte==0 );
     /* An INDEXED BY clause specifies a particular index to use */
     pProbe = pSrc->u2.pIBIndex;
   }else if( !HasRowid(pTab) ){