1 files changed, 16 insertions, 4 deletions

diff --git a/src/expr.c b/src/expr.c
index 2bc5eae20..77b5e0ad6 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -2660,7 +2660,7 @@ static int sqlite3InRhsIsConstant(Expr *pIn){
 ** all members of the RHS set, skipping duplicates.
 **
 ** A cursor is opened on the b-tree object that is the RHS of the IN operator
-** and pX->iTable is set to the index of that cursor.
+** and the *piTab parameter is set to the index of that cursor.
 **
 ** The returned value of this function indicates the b-tree type, as follows:
 **
@@ -2680,7 +2680,10 @@ static int sqlite3InRhsIsConstant(Expr *pIn){
 ** If the RHS of the IN operator is a list or a more complex subquery, then
 ** an ephemeral table might need to be generated from the RHS and then
 ** pX->iTable made to point to the ephemeral table instead of an
-** existing table.
+** existing table.  In this case, the creation and initialization of the
+** ephmeral table might be put inside of a subroutine, the EP_Subrtn flag
+** will be set on pX and the pX->y.sub fields will be set to show where
+** the subroutine is coded.
 **
 ** The inFlags parameter must contain, at a minimum, one of the bits
 ** IN_INDEX_MEMBERSHIP or IN_INDEX_LOOP but not both.  If inFlags contains
@@ -2741,12 +2744,17 @@ 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
@@ -2912,6 +2920,8 @@ int sqlite3FindInIndex(
    && ExprUseXList(pX)
    && (!sqlite3InRhsIsConstant(pX) || pX->x.pList->nExpr<=2)
   ){
+    pParse->nTab--;  /* Back out the allocation of the unused cursor */
+    iTab = -1;       /* Cursor is not allocated */
     eType = IN_INDEX_NOOP;
   }
 
@@ -3078,7 +3088,9 @@ 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;
     }