Remove QtScript connection when receiver QObject has been deleted

We don't want to have to listen to the destroyed() signal for every
receiver object of a connection, and likewise we don't want to create
a QObject to handle each connection; instead, remove the connection
lazily at signal emission time after we've detected that the receiver
has been deleted.

Task-number: QTBUG-7313
Reviewed-by: Simon Hausmann

1 files changed, 8 insertions, 1 deletions

diff --git a/src/script/bridge/qscriptqobject.cpp b/src/script/bridge/qscriptqobject.cpp
index 3f4f6bb..db312bc 100644
--- a/src/script/bridge/qscriptqobject.cpp
+++ b/src/script/bridge/qscriptqobject.cpp
@@ -2220,7 +2220,14 @@ void QObjectConnectionManager::execute(int slotIndex, void **argv)
     JSC::call(exec, slot, callType, callData, thisObject, jscArgs);
 
     if (exec->hadException()) {
-        engine->emitSignalHandlerException();
+        if (slot.inherits(&QtFunction::info) && !static_cast<QtFunction*>(JSC::asObject(slot))->qobject()) {
+            // The function threw an error because the target QObject has been deleted.
+            // The connections list is stale; remove the signal handler and ignore the exception.
+            removeSignalHandler(sender(), signalIndex, receiver, slot);
+            exec->clearException();
+        } else {
+            engine->emitSignalHandlerException();
+        }
     }
 }