Fix major kompmgr flickering on sesson startup

Note that there is still a (small) single flicker that occurs as the composition is engaged,
however this is an Xorg design defect and can only be fixed by loading composition support in kdm


git-svn-id: svn://anonsvn.kde.org/home/kde/branches/trinity/kdebase@1246526 283d02a7-25f6-0310-bc7c-ecb5cbfe19da

kwin/workspace.cpp

@@ -2567,6 +2567,21 @@ void Workspace::helperDialog( const TQString& message, const Client* c )
 
 void Workspace::startKompmgr()
 {
+    // See if the desktop is loaded yet
+    Atom type;
+    int format;
+    unsigned long length, after;
+    unsigned char* data_root;
+    Atom prop_root;
+    prop_root = XInternAtom(qt_xdisplay(), "_XROOTPMAP_ID", False);
+    if( XGetWindowProperty( qt_xdisplay(), qt_xrootwin(), prop_root, 0L, 1L, False, AnyPropertyType, &type, &format, &length, &after, &data_root) == Success && data_root != NULL ) {
+        // Root pixmap is available; OK to load...
+    }
+    else {
+        // Try again a bit later!
+        TQTimer::singleShot( 200, this, TQT_SLOT(startKompmgr()) );
+        return;
+    }
     if (!kompmgr || kompmgr->isRunning())
         return;
     if (!kompmgr->start(KProcess::OwnGroup, KProcess::Stderr))