Fix TDM hang in certain circumstances when themed greeter is deleted

This resolves Bug 1453
Resolve themed greeter drawing inconsistencies between composited and non-composited mode
(cherry picked from commit 3421d01bb00aaf52883a4d21eade96e9c663e05d)

2 files changed, 15 insertions, 2 deletions

diff --git a/kwin/main.cpp b/kwin/main.cpp
index dcc4a7438..3c1dd171a 100644
--- a/kwin/main.cpp
+++ b/kwin/main.cpp
@@ -44,6 +44,7 @@ Options* options;
 Atoms* atoms;
 
 int screen_number = -1;
+bool disable_kwin_composition_manager = false;
 
 static bool initting = FALSE;
 
@@ -95,8 +96,13 @@ Application::Application( )
         config()->reparseConfiguration();
         }
 
-    if (screen_number == -1)
+    if (screen_number == -1) {
         screen_number = DefaultScreen(qt_xdisplay());
+    }
+
+    if (args->isSet( "disablecompositionmanager" )) {
+        disable_kwin_composition_manager = true;
+    }
 
     if( !owner.claim( args->isSet( "replace" ), true ))
         {
@@ -234,6 +240,7 @@ static KCmdLineOptions args[] =
     {
         { "lock", I18N_NOOP("Disable configuration options"), 0 },
         { "replace", I18N_NOOP("Replace already-running ICCCM2.0-compliant window manager"), 0 },
+        { "disablecompositionmanager", I18N_NOOP("Do not start composition manager"), 0 },
         KCmdLineLastOption
     };
 
diff --git a/kwin/workspace.cpp b/kwin/workspace.cpp
index d358869b8..957689364 100644
--- a/kwin/workspace.cpp
+++ b/kwin/workspace.cpp
@@ -58,9 +58,14 @@ KProcess* kompmgr = 0;
 KSelectionOwner* kompmgr_selection;
 
 bool allowKompmgrRestart = TRUE;
+extern bool disable_kwin_composition_manager;
 
 bool supportsCompMgr()
 {
+    if (disable_kwin_composition_manager) {
+        return false;
+    }
+
     int i;
 
     bool damageExt = XQueryExtension(qt_xdisplay(), "DAMAGE", &i, &i, &i);
@@ -212,8 +217,9 @@ Workspace::Workspace( bool restore )
     connect( kapp->desktop(), TQT_SIGNAL( resized( int )), TQT_SLOT( desktopResized()));
 #endif
 
-    if (!supportsCompMgr())
+    if (!supportsCompMgr()) {
         options->useTranslucency = false;
+    }
 
     // start kompmgr - i wanted to put this into main.cpp, but that would prevent dcop support, as long as Application was no dcop_object
     if (options->useTranslucency)