Index: src/where.c
==================================================================
--- src/where.c
+++ src/where.c
@@ -5082,10 +5082,11 @@
       sqlite3VdbeResolveLabel(v, pLevel->addrNxt);
       for(j=pLevel->u.in.nIn, pIn=&pLevel->u.in.aInLoop[j-1]; j>0; j--, pIn--){
         sqlite3VdbeJumpHere(v, pIn->addrInTop+1);
         if( pIn->eEndLoopOp!=OP_Noop ){
           if( pIn->nPrefix ){
+            assert( pLoop->wsFlags & WHERE_IN_EARLYOUT );
             sqlite3VdbeAddOp4Int(v, OP_IfNoHope, pLevel->iIdxCur,
                               sqlite3VdbeCurrentAddr(v)+2,
                               pIn->iBase, pIn->nPrefix);
             VdbeCoverage(v);
           }

Index: src/whereInt.h
==================================================================
--- src/whereInt.h
+++ src/whereInt.h
@@ -555,5 +555,6 @@
 #define WHERE_MULTI_OR     0x00002000  /* OR using multiple indices */
 #define WHERE_AUTO_INDEX   0x00004000  /* Uses an ephemeral index */
 #define WHERE_SKIPSCAN     0x00008000  /* Uses the skip-scan algorithm */
 #define WHERE_UNQ_WANTED   0x00010000  /* WHERE_ONEROW would have been helpful*/
 #define WHERE_PARTIALIDX   0x00020000  /* The automatic index is partial */
+#define WHERE_IN_EARLYOUT  0x00040000  /* Perhaps quit IN loops early */

Index: src/wherecode.c
==================================================================
--- src/wherecode.c
+++ src/wherecode.c
@@ -593,10 +593,11 @@
             pIn->iCur = iTab;
             pIn->eEndLoopOp = bRev ? OP_PrevIfOpen : OP_NextIfOpen;
             if( (pLoop->wsFlags & WHERE_VIRTUALTABLE)==0 ){
               pIn->iBase = iReg - i;
               pIn->nPrefix = i;
+              pLoop->wsFlags |= WHERE_IN_EARLYOUT;
             }else{
               pIn->nPrefix = 0;
             }
           }else{
             pIn->eEndLoopOp = OP_Noop;
@@ -1662,11 +1663,11 @@
     if( pLoop->nSkip>0 && nConstraint==pLoop->nSkip ){
       /* The skip-scan logic inside the call to codeAllEqualityConstraints()
       ** above has already left the cursor sitting on the correct row,
       ** so no further seeking is needed */
     }else{
-      if( pLoop->wsFlags & WHERE_IN_ABLE ){
+      if( pLoop->wsFlags & WHERE_IN_EARLYOUT ){
         sqlite3VdbeAddOp1(v, OP_SeekHit, iIdxCur);
       }
       op = aStartOp[(start_constraints<<2) + (startEq<<1) + bRev];
       assert( op!=0 );
       sqlite3VdbeAddOp4Int(v, op, iIdxCur, addrNxt, regBase, nConstraint);
@@ -1728,11 +1729,11 @@
       testcase( op==OP_IdxGE );  VdbeCoverageIf(v, op==OP_IdxGE );
       testcase( op==OP_IdxLT );  VdbeCoverageIf(v, op==OP_IdxLT );
       testcase( op==OP_IdxLE );  VdbeCoverageIf(v, op==OP_IdxLE );
     }
 
-    if( pLoop->wsFlags & WHERE_IN_ABLE ){
+    if( pLoop->wsFlags & WHERE_IN_EARLYOUT ){
       sqlite3VdbeAddOp2(v, OP_SeekHit, iIdxCur, 1);
     }
 
     /* Seek the table cursor, if required */
     if( omitTable ){