Improvement on check-in [a193749730d6cfba] so that the subroutine call to

the IN operator right-hand side generator from the RIGHT JOIN no-match logic
does not generate unreachable byte code.

FossilOrigin-Name: cc458317bd77046c4328715ae9e3409f3f4cd422a01162cb33405ef3a142b0a3

3 files changed, 12 insertions, 9 deletions

diff --git a/src/expr.c b/src/expr.c
index f8ee68dc2..8e47578cc 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2743,12 +2743,17 @@ int sqlite3FindInIndex(
 ){
   Select *p;                            /* SELECT to the right of IN operator */
   int eType = 0;                        /* Type of RHS table. IN_INDEX_* */
-  int iTab = pParse->nTab++;            /* Cursor of the RHS table */
+  int iTab;                             /* Cursor of the RHS table */
   int mustBeUnique;                     /* True if RHS must be unique */
   Vdbe *v = sqlite3GetVdbe(pParse);     /* Virtual machine being coded */
 
   assert( pX->op==TK_IN );
   mustBeUnique = (inFlags & IN_INDEX_LOOP)!=0;
+  if( pX->iTable && (inFlags & IN_INDEX_REUSE_CUR)!=0 ){
+    iTab = pX->iTable;
+  }else{
+    iTab = pParse->nTab++;
+  }
 
   /* If the RHS of this IN(...) operator is a SELECT, and if it matters 
   ** whether or not the SELECT result contains NULL values, check whether
@@ -3082,7 +3087,9 @@ void sqlite3CodeRhsOfIN(
       assert( ExprUseYSub(pExpr) );
       sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
                         pExpr->y.sub.iAddr);
-      sqlite3VdbeAddOp2(v, OP_OpenDup, iTab, pExpr->iTable);
+      if( iTab!=pExpr->iTable ){
+        sqlite3VdbeAddOp2(v, OP_OpenDup, iTab, pExpr->iTable);
+      }
       sqlite3VdbeJumpHere(v, addrOnce);
       return;
     }
diff --git a/src/sqliteInt.h b/src/sqliteInt.h
index e526a775c..e9f0af544 100644
--- a/src/sqliteInt.h
+++ b/src/sqliteInt.h
@@ -5315,6 +5315,7 @@ const char *sqlite3JournalModename(int);
 #define IN_INDEX_NOOP_OK     0x0001  /* OK to return IN_INDEX_NOOP */
 #define IN_INDEX_MEMBERSHIP  0x0002  /* IN operator used for membership test */
 #define IN_INDEX_LOOP        0x0004  /* IN operator used as a loop */
+#define IN_INDEX_REUSE_CUR   0x0008  /* Reuse prior table cursor */
 int sqlite3FindInIndex(Parse *, Expr *, u32, int*, int*, int*);
 
 int sqlite3JournalOpen(sqlite3_vfs *, const char *, sqlite3_file *, int, int);
diff --git a/src/wherecode.c b/src/wherecode.c
index 333295a48..d4470ac4d 100644
--- a/src/wherecode.c
+++ b/src/wherecode.c
@@ -612,7 +612,7 @@ static int codeEqualityTerm(
       eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, 0, &iTab);
     }else{
       Expr *pExpr = pTerm->pExpr;
-      if(  pExpr->iTable==0 || !ExprHasProperty(pExpr, EP_Subrtn) ){
+      if( pExpr->iTable==0 || !ExprHasProperty(pExpr, EP_Subrtn) ){
         sqlite3 *db = pParse->db;
         pX = removeUnindexableInClauseTerms(pParse, iEq, pLoop, pX);
         if( !db->mallocFailed ){
@@ -622,14 +622,9 @@ static int codeEqualityTerm(
         }
         sqlite3ExprDelete(db, pX);
       }else{
-        int j1;
-        sqlite3VdbeAddOp2(v, OP_Gosub, pExpr->y.sub.regReturn,
-                          pExpr->y.sub.iAddr);
-        j1 = sqlite3VdbeAddOp0(v, OP_Goto);
         aiMap = (int*)sqlite3DbMallocZero(pParse->db, sizeof(int)*nEq);
-        eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP, 0, aiMap,&iTab);
+        eType = sqlite3FindInIndex(pParse, pX, IN_INDEX_LOOP|IN_INDEX_REUSE_CUR,                                   0, aiMap,&iTab);
         iTab = pExpr->iTable;
-        sqlite3VdbeJumpHere(v, j1);
       }
       pX = pExpr;
     }