Correct handling of OUTER JOIN when on or the other operand is a subquery

implemented using the VALUES-as-coroutine optimization.
dbsqlfuzz bde3bf80aedf25afa56e2997a0545a314765d3f8.

FossilOrigin-Name: 8c0f69e0e4ae0a446838cc193bfd4395fd251f3c7659b35ac388e5a0a7650a66

3 files changed, 29 insertions, 8 deletions

diff --git a/src/vdbe.c b/src/vdbe.c
index ed1d277b2..143fd49c1 100644
--- a/src/vdbe.c
+++ b/src/vdbe.c
@@ -1152,7 +1152,9 @@ jump_to_p2:
 **
 ** The instruction at the address in register P1 is a Yield.
 ** Jump to the P2 parameter of that Yield.
-** After the jump, register P1 becomes undefined.
+** After the jump, the value register P1 is left with a value
+** such that subsequent OP_Yields go back to the this same
+** OP_EndCoroutine instruction.
 **
 ** See also: InitCoroutine
 */
@@ -1164,8 +1166,8 @@ case OP_EndCoroutine: {           /* in1 */
   pCaller = &aOp[pIn1->u.i];
   assert( pCaller->opcode==OP_Yield );
   assert( pCaller->p2>=0 && pCaller->p2<p->nOp );
+  pIn1->u.i = (int)(pOp - p->aOp) - 1;
   pOp = &aOp[pCaller->p2 - 1];
-  pIn1->flags = MEM_Undefined;
   break;
 }
 
diff --git a/src/where.c b/src/where.c
index 65b6ae2c9..93984347b 100644
--- a/src/where.c
+++ b/src/where.c
@@ -6940,8 +6940,17 @@ void sqlite3WhereEnd(WhereInfo *pWInfo){
       addr = sqlite3VdbeAddOp1(v, OP_IfPos, pLevel->iLeftJoin); VdbeCoverage(v);
       assert( (ws & WHERE_IDX_ONLY)==0 || (ws & WHERE_INDEXED)!=0 );
       if( (ws & WHERE_IDX_ONLY)==0 ){
-        assert( pLevel->iTabCur==pTabList->a[pLevel->iFrom].iCursor );
-        sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iTabCur);
+        SrcItem *pSrc = &pTabList->a[pLevel->iFrom];
+        assert( pLevel->iTabCur==pSrc->iCursor );
+        if( pSrc->fg.viaCoroutine ){
+          int m, n;
+          n = pSrc->regResult;
+          assert( pSrc->pTab!=0 );
+          m = pSrc->pTab->nCol;
+          sqlite3VdbeAddOp3(v, OP_Null, 0, n, n+m-1);
+        }else{
+          sqlite3VdbeAddOp1(v, OP_NullRow, pLevel->iTabCur);
+        }
       }
       if( (ws & WHERE_INDEXED)
        || ((ws & WHERE_MULTI_OR) && pLevel->u.pCoveringIdx)
diff --git a/src/wherecode.c b/src/wherecode.c
index 1f9c84f00..e91bc283b 100644
--- a/src/wherecode.c
+++ b/src/wherecode.c
@@ -2730,11 +2730,21 @@ SQLITE_NOINLINE void sqlite3WhereRightJoinLoop(
                                   pRJ->regReturn);
   for(k=0; k<iLevel; k++){
     int iIdxCur;
+    SrcItem *pRight;
+    assert( pWInfo->a[k].pWLoop->iTab == pWInfo->a[k].iFrom );
+    pRight = &pWInfo->pTabList->a[pWInfo->a[k].iFrom];
     mAll |= pWInfo->a[k].pWLoop->maskSelf;
-    sqlite3VdbeAddOp1(v, OP_NullRow, pWInfo->a[k].iTabCur);
-    iIdxCur = pWInfo->a[k].iIdxCur;
-    if( iIdxCur ){
-      sqlite3VdbeAddOp1(v, OP_NullRow, iIdxCur);
+    if( pRight->fg.viaCoroutine ){
+      sqlite3VdbeAddOp3(
+          v, OP_Null, 0, pRight->regResult, 
+          pRight->regResult + pRight->pSelect->pEList->nExpr-1
+      );
+    }else{
+      sqlite3VdbeAddOp1(v, OP_NullRow, pWInfo->a[k].iTabCur);
+      iIdxCur = pWInfo->a[k].iIdxCur;
+      if( iIdxCur ){
+        sqlite3VdbeAddOp1(v, OP_NullRow, iIdxCur);
+      }
     }
   }
   if( (pTabItem->fg.jointype & JT_LTORJ)==0 ){