webOS: Fix allocateTimerId

Change-Id: I8b3777f4035401763d86b0245de43b63573b9ea6 Reviewed-by: Thiago Macieira <[email protected]> Reviewed-by: Mårten Nordheim <[email protected]> (cherry picked from commit 4683b0b)
boris-fx · Jun 4, 2020 · a288ff8 · a288ff8
1 parent 25f2f41
commit a288ff8
Showing 1 changed file with 8 additions and 1 deletion.
diff --git a/src/corelib/kernel/qabstracteventdispatcher.cpp b/src/corelib/kernel/qabstracteventdispatcher.cpp
@@ -90,7 +90,14 @@ Q_GLOBAL_STATIC(QtTimerIdFreeList, timerIdFreeList)
 
 int QAbstractEventDispatcherPrivate::allocateTimerId()
 {
-    return timerIdFreeList()->next();
+    // This function may be called after timerIdFreeList() has been destructed
+    // for example in case when application exits without waiting for
+    // running threads to exit and running thread finished() has been connected
+    // to a slot which triggers a sequence that registers new timer.
+    // See https://bugreports.qt-project.org/browse/QTBUG-38957.
+    if (QtTimerIdFreeList *fl = timerIdFreeList())
+        return fl->next();
+    return 0; // Note! returning 0 generates a warning
 }
 
 void QAbstractEventDispatcherPrivate::releaseTimerId(int timerId)