From 17ca566154321eb6d81204a8cd54429a6725ed92 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20L=C3=BCbking?= <thomas.luebking@gmail.com>
Date: Wed, 26 Mar 2014 18:03:54 +0100
Subject: [PATCH] setup desktopgrid for screencount change

prevents segfaults..

CCBUG: 326032

Forward port of 4fe7460e03f5cd4f64d85d20a6d85ce3a66f4ae8 from kde-workspace
---
 effects/desktopgrid/desktopgrid.cpp | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/effects/desktopgrid/desktopgrid.cpp b/effects/desktopgrid/desktopgrid.cpp
index 8b03a55f25..97cb2a3f11 100644
--- a/effects/desktopgrid/desktopgrid.cpp
+++ b/effects/desktopgrid/desktopgrid.cpp
@@ -79,6 +79,7 @@ DesktopGridEffect::DesktopGridEffect()
     connect(effects, SIGNAL(windowDeleted(KWin::EffectWindow*)), this, SLOT(slotWindowDeleted(KWin::EffectWindow*)));
     connect(effects, SIGNAL(numberDesktopsChanged(uint)), this, SLOT(slotNumberDesktopsChanged(uint)));
     connect(effects, SIGNAL(windowGeometryShapeChanged(KWin::EffectWindow*,QRect)), this, SLOT(slotWindowGeometryShapeChanged(KWin::EffectWindow*,QRect)));
+    connect(effects, &EffectsHandler::numberScreensChanged, this, &DesktopGridEffect::setup);
 
     // Load all other configuration details
     reconfigure(ReconfigureAll);
@@ -1060,9 +1061,13 @@ void DesktopGridEffect::setActive(bool active)
 
 void DesktopGridEffect::setup()
 {
-    keyboardGrab = effects->grabKeyboard(this);
-    effects->startMouseInterception(this, Qt::PointingHandCursor);
-    effects->setActiveFullScreenEffect(this);
+    if (!isActive())
+        return;
+    if (!keyboardGrab) {
+        keyboardGrab = effects->grabKeyboard(this);
+        effects->startMouseInterception(this, Qt::PointingHandCursor);
+        effects->setActiveFullScreenEffect(this);
+    }
     setHighlightedDesktop(effects->currentDesktop());
 
     // Soft highlighting