QMetaMethod::invoke: compare the QMetaType id of the return types

Since Qt5, the QMetaObject do not contains the string name of the
builtin types, but only the QMetaType id. QMetaMethod::typeName
convert back from the id to the string. But if the type is aliased,
the string of the main type is returned.

This was the case for example for qint64 which is transformed to
"qlonglong".

This causes a regression in QMetaType::invoke when trying to invoke a
method which return an aliased type, since the string comparison would
fail.

Fix the problem by also comparing the metatype id.

Changelog: QMetaMethod::invoke: Fix return of aliased meta type

Task-number: QTBUG-33222
Change-Id: Iec7b99dcbf7b23eb818de74f413e4451ce510ac4
Reviewed-by: Jędrzej Nowacki <jedrzej.nowacki@digia.com>

1 files changed, 7 insertions, 2 deletions

diff --git a/src/corelib/kernel/qmetaobject.cpp b/src/corelib/kernel/qmetaobject.cpp
index 4dc766ecc5..8d6cf5beb5 100644
--- a/src/corelib/kernel/qmetaobject.cpp
+++ b/src/corelib/kernel/qmetaobject.cpp
@@ -42,6 +42,7 @@
 #include "qmetaobject.h"
 #include "qmetatype.h"
 #include "qobject.h"
+#include "qmetaobject_p.h"
 
 #include <qcoreapplication.h>
 #include <qcoreevent.h>
@@ -2098,8 +2099,12 @@ bool QMetaMethod::invoke(QObject *object,
         if (qstrcmp(returnValue.name(), retType) != 0) {
             // normalize the return value as well
             QByteArray normalized = QMetaObject::normalizedType(returnValue.name());
-            if (qstrcmp(normalized.constData(), retType) != 0)
-                return false;
+            if (qstrcmp(normalized.constData(), retType) != 0) {
+                // String comparison failed, try compare the metatype.
+                int t = returnType();
+                if (t == QMetaType::UnknownType || t != QMetaType::type(normalized))
+                    return false;
+            }
         }
     }