From b61b146209ff13e50c7c7dd5d636ab98f3b8b5d9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Gr=C3=A4=C3=9Flin?= <mgraesslin@kde.org>
Date: Sat, 26 May 2012 16:57:37 +0200
Subject: [PATCH] Prevent null pointer passed to
 Client::belongToSameApplication

Another fix for a regression introduced with
431aad6d6994695e72697fcc3299ec2cb6f0684e

BUG: 300667
FIXED-IN: 4.9.0
REVIEW: 105062
---
 layers.cpp | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/layers.cpp b/layers.cpp
index 804e3ddca6..4521554fb9 100644
--- a/layers.cpp
+++ b/layers.cpp
@@ -326,12 +326,17 @@ void Workspace::lowerClientWithinApplication(Client* c)
     // first try to put it below the bottom-most window of the application
     for (ToplevelList::Iterator it = unconstrained_stacking_order.begin();
             it != unconstrained_stacking_order.end();
-            ++it)
-        if (Client::belongToSameApplication(qobject_cast<Client*>(*it), c)) {
+            ++it) {
+        Client *client = qobject_cast<Client*>(*it);
+        if (!client) {
+            continue;
+        }
+        if (Client::belongToSameApplication(client, c)) {
             unconstrained_stacking_order.insert(it, c);
             lowered = true;
             break;
         }
+    }
     if (!lowered)
         unconstrained_stacking_order.prepend(c);
     // ignore mainwindows