Do not create Deleted on Workspace Shutdown

When the Workspace is shutting down the compositor is torn down
before Clients and Unmanaged are released. This means that there
is no need to create the Deleted windows.

Furthermore creating the Deleted manipulates the stacking_order
while Workspace dtor loops over this list to release all clients.
This may cause crashes.

BUG: 282933
FIXED-IN: 4.9.0
REVIEW: 104690

client.cpp

@@ -240,7 +240,10 @@ void Client::releaseWindow(bool on_shutdown)
 {
     assert(!deleting);
     deleting = true;
-    Deleted* del = Deleted::create(this);
+    Deleted* del = NULL;
+    if (!on_shutdown) {
+        del = Deleted::create(this);
+    }
     if (moveResizeMode)
         emit clientFinishUserMovedResized(this);
     emit windowClosed(this, del);
@@ -291,8 +294,10 @@ void Client::releaseWindow(bool on_shutdown)
     XDestroyWindow(display(), frameId());
     //frame = None;
     --block_geometry_updates; // Don't use GeometryUpdatesBlocker, it would now set the geometry
-    disownDataPassedToDeleted();
-    del->unrefWindow();
+    if (!on_shutdown) {
+        disownDataPassedToDeleted();
+        del->unrefWindow();
+    }
     checkNonExistentClients();
     deleteClient(this, Allowed);
     ungrabXServer();

unmanaged.cpp

@@ -80,9 +80,12 @@ bool Unmanaged::track(Window w)
     return true;
 }
 
-void Unmanaged::release()
+void Unmanaged::release(bool on_shutdown)
 {
-    Deleted* del = Deleted::create(this);
+    Deleted* del = NULL;
+    if (!on_shutdown) {
+        del = Deleted::create(this);
+    }
     emit windowClosed(this, del);
     finishCompositing();
     workspace()->removeUnmanaged(this, Allowed);
@@ -91,9 +94,11 @@ void Unmanaged::release()
             XShapeSelectInput(display(), window(), NoEventMask);
         XSelectInput(display(), window(), NoEventMask);
     }
-    addWorkspaceRepaint(del->visibleRect());
-    disownDataPassedToDeleted();
-    del->unrefWindow();
+    if (!on_shutdown) {
+        addWorkspaceRepaint(del->visibleRect());
+        disownDataPassedToDeleted();
+        del->unrefWindow();
+    }
     deleteUnmanaged(this, Allowed);
 }
 

unmanaged.h

@@ -35,7 +35,7 @@ class Unmanaged
 public:
     Unmanaged(Workspace *ws);
     bool windowEvent(XEvent* e);
-    void release();
+    void release(bool on_shutdown = false);
     bool track(Window w);
     static void deleteUnmanaged(Unmanaged* c, allowed_t);
     virtual int desktop() const;

workspace.cpp

@@ -503,7 +503,7 @@ Workspace::~Workspace()
         desktops.removeAll(c);
     }
     for (UnmanagedList::iterator it = unmanaged.begin(), end = unmanaged.end(); it != end; ++it)
-        (*it)->release();
+        (*it)->release(true);
     delete m_outline;
     discardPopup();
     XDeleteProperty(display(), rootWindow(), atoms->kwin_running);