From 3c4619893c0dee43ec7be568e89ed5c520849d1b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20Gr=C3=A4=C3=9Flin?= <mgraesslin@kde.org>
Date: Thu, 19 May 2016 16:37:59 +0200
Subject: [PATCH] Don't update decoration when ServerSideDecoration gets
 destroyed and ShellClient is unmapped

Summary:
Most likely the window is in the process of getting destroyed. In that
case the following destroy of the Surface is also going to destroy the
decoration.

This was causing an interesting effect with the QQuickRenderControl used
by Aurorae. When getting destroyed it ensures that all posted events get
processed. This includes the destroy of the Surface which entered
ShellClient::destroyClient which again destroyed the decoration. In other
words a recursive destroy which ended with wonderful crashers due to
double deletions.

If the window is not unmapped this might still cause problems: more
testing needed.

Reviewers: #plasma

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D1641
---
 shell_client.cpp | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/shell_client.cpp b/shell_client.cpp
index 29c9bb8a63..c4cf5ddb46 100644
--- a/shell_client.cpp
+++ b/shell_client.cpp
@@ -981,10 +981,13 @@ void ShellClient::installServerSideDecoration(KWayland::Server::ServerSideDecora
     connect(m_serverDecoration, &ServerSideDecorationInterface::destroyed, this,
         [this] {
             m_serverDecoration = nullptr;
-            if (!Workspace::self()) {
+            if (m_closing || !Workspace::self()) {
                 return;
             }
-            updateDecoration(true);
+            if (!m_unmapped) {
+                // maybe delay to next event cycle in case the ShellClient is getting destroyed, too
+                updateDecoration(true);
+            }
         }
     );
     if (!m_unmapped) {