Don't crash if queued signal handler no longer exists

Task-number: QTBUG-26261

Change-Id: Ie269c56c0336b1c937d4ec551f913ae7537d0338
Reviewed-by: Olivier Goffart <ogoffart@woboq.com>

1 files changed, 7 insertions, 1 deletions

diff --git a/src/script/bridge/qscriptqobject.cpp b/src/script/bridge/qscriptqobject.cpp
index 962479f..807c94c 100644
--- a/src/script/bridge/qscriptqobject.cpp
+++ b/src/script/bridge/qscriptqobject.cpp
@@ -2092,7 +2092,13 @@ void QObjectConnectionManager::execute(int slotIndex, void **argv)
             }
         }
     }
-    Q_ASSERT(slot && slot.isObject());
+    if (!slot) {
+        // This connection no longer exists (can happen if the signal is
+        // emitted from another thread and the call gets queued, but the
+        // connection is removed before the QMetaCallEvent gets processed).
+        return;
+    }
+    Q_ASSERT(slot.isObject());
 
     if (engine->isCollecting()) {
         qWarning("QtScript: can't execute signal handler during GC");