QConnectedReplicaImplementation: don't call deleteLater() on a nullptr

It's undefined behavior according to C++, even if you don't touch
members, and only happened to work until
qtbase/13074a967f18ed348ab744f7ff831965607a6421 which made it stop
"working".

Add an explicit nullptr check before calling deleteLater().

Amends 35dd08098f8a4b422d523792261aefe039358f6a(!).

Fixes: QTBUG-120242
Pick-to: 6.5 6.2 5.15
Change-Id: I9ce95f8c8f917549ccfd0040f0cd4f483c3a28d0
Reviewed-by: Juha Vuolle <juha.vuolle@qt.io>
(cherry picked from commit 4ef440b458c526ad24a3e87d480ddb44c76c6438)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
(cherry picked from commit 405812b7609fbaf2be2575175fabdc4fdc77c1f7)

1 files changed, 4 insertions, 2 deletions

diff --git a/src/remoteobjects/qremoteobjectreplica.cpp b/src/remoteobjects/qremoteobjectreplica.cpp
index 4e53d9f..7134abf 100644
--- a/src/remoteobjects/qremoteobjectreplica.cpp
+++ b/src/remoteobjects/qremoteobjectreplica.cpp
@@ -119,8 +119,10 @@ QConnectedReplicaImplementation::~QConnectedReplicaImplementation()
         sendCommand();
     }
     for (auto prop : m_propertyStorage) {
-        if (prop.canConvert<QObject*>())
-            prop.value<QObject *>()->deleteLater();
+        if (prop.canConvert<QObject*>()) {
+            if (auto o = prop.value<QObject*>())
+                o->deleteLater();
+        }
     }
 }