Fix crash when loading invalid QML with behavior on invalid group property

Behaviors require the creation of a meta-object. However when trying to
create a behavior on a non-existent group property, we don't have a
base meta-object to base the "new" meta-object on, therefore this patch
adds a null pointer check.

The error in the QML file itself will be caught later on. The added test
ensures that as well as that it doesn't crash of course.

Change-Id: If73116053464e7e69b02ef59e8387060835083c8
Task-number: QTBUG-40369
Reviewed-by: Sérgio Martins <sergio.martins@kdab.com>
Reviewed-by: Lars Knoll <lars.knoll@digia.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/src/qml/compiler/qqmltypecompiler.cpp b/src/qml/compiler/qqmltypecompiler.cpp
index dacaa14a3d..f5cb5db369 100644
--- a/src/qml/compiler/qqmltypecompiler.cpp
+++ b/src/qml/compiler/qqmltypecompiler.cpp
@@ -541,12 +541,14 @@ bool QQmlPropertyCacheCreator::buildMetaObjectRecursively(int objectIndex, int r
         Q_ASSERT(baseTypeCache);
     }
 
-    if (needVMEMetaObject) {
-        if (!createMetaObject(objectIndex, obj, baseTypeCache))
-            return false;
-    } else if (baseTypeCache) {
-        propertyCaches[objectIndex] = baseTypeCache;
-        baseTypeCache->addref();
+    if (baseTypeCache) {
+        if (needVMEMetaObject) {
+            if (!createMetaObject(objectIndex, obj, baseTypeCache))
+                return false;
+        } else {
+            propertyCaches[objectIndex] = baseTypeCache;
+            baseTypeCache->addref();
+        }
     }
 
     if (propertyCaches.at(objectIndex)) {