Remove Window objects from the corresponding Select.pWin list when they are deleted, as they are, for example, when the ORDER BY clause is optimized out.

FossilOrigin-Name: fd7316cda0fdfe86985f41a97dff3beba188606ec9bc6fef38a686a6976a6e01

1 files changed, 10 insertions, 3 deletions

diff --git a/src/expr.c b/src/expr.c
index 56b3148ed..571e9e494 100644
--- a/src/expr.c
+++ b/src/expr.c
@@ -1326,10 +1326,17 @@ static With *withDup(sqlite3 *db, With *p){
 */
 static int gatherSelectWindowsCallback(Walker *pWalker, Expr *pExpr){
   if( pExpr->op==TK_FUNCTION && ExprHasProperty(pExpr, EP_WinFunc) ){
-    assert( pExpr->y.pWin );
+    Select *pSelect = pWalker->u.pSelect;
+    Window *pWin = pExpr->y.pWin;
+    assert( pWin );
     assert( IsWindowFunc(pExpr) );
-    pExpr->y.pWin->pNextWin = pWalker->u.pSelect->pWin;
-    pWalker->u.pSelect->pWin = pExpr->y.pWin;
+    if( pSelect->pWin ){
+      *pSelect->pWin->ppThis = pSelect->pWin->pNextWin;
+      pSelect->pWin->ppThis = &pWin->pNextWin;
+    }
+    pWin->pNextWin = pSelect->pWin;
+    pWin->ppThis = &pSelect->pWin;
+    pSelect->pWin = pWin;
   }
   return WRC_Continue;
 }