[mutter] window-props: Add FORCE_INIT flag to force hooks for unset properties

[Florian Müllner <fmuellner src gnome org>]

commit b7119c55a69523d9fd8b392e81329c7819a15a01
Author: Florian Müllner <fmuellner gnome org>
Date:   Fri Aug 1 15:23:47 2014 +0200

    window-props: Add FORCE_INIT flag to force hooks for unset properties
    
    Since commit a7b7213017441ecc9, we rely on the standard property
    system to initialize the window type (and likewise for the window
    role since commit 031154a4002d59). However as property hooks are
    never run for properties that are not set, we end up not initializing
    the window type correctly for windows with no _NET_WM_WINDOW_TYPE
    property (which includes virtually all OR windows, causing them to
    show up in pagers and the Shell overview and resulting in frequent
    crashes due to breaking reasonable assumptions all over the place).
    
    Introduce a new FORCE_INIT flag to allow forcing hooks to run
    even when the corresponding property is unset, and use it for
    both _NET_WM_WINDOW_TYPE and _NET_WM_WINDOW_ROLE.

 src/x11/window-props.c |   11 ++++++++---
 1 files changed, 8 insertions(+), 3 deletions(-)
---
diff --git a/src/x11/window-props.c b/src/x11/window-props.c
index d2ba87e..b76f6de 100644
--- a/src/x11/window-props.c
+++ b/src/x11/window-props.c
@@ -64,6 +64,7 @@ typedef enum {
   LOAD_INIT  = (1 << 0),
   INCLUDE_OR = (1 << 1),
   INIT_ONLY  = (1 << 2),
+  FORCE_INIT = (1 << 3),
 } MetaPropHookFlags;
 
 struct _MetaWindowPropHooks
@@ -157,7 +158,8 @@ meta_window_load_initial_properties (MetaWindow *window)
            * to call the reload function; this is different from a notification
            * where disappearance of a previously present value is significant.
            */
-          if (values[j].type != META_PROP_VALUE_INVALID)
+          if (values[j].type != META_PROP_VALUE_INVALID ||
+              hooks->flags & FORCE_INIT)
             reload_prop_value (window, hooks, &values[j], TRUE);
           ++j;
         }
@@ -1804,8 +1806,8 @@ meta_display_init_window_prop_hooks (MetaDisplay *display)
     { display->atom__NET_WM_ICON_GEOMETRY, META_PROP_VALUE_CARDINAL_LIST, reload_icon_geometry, LOAD_INIT },
     { display->atom_WM_CLIENT_LEADER,  META_PROP_VALUE_INVALID, complain_about_broken_client, NONE },
     { display->atom_SM_CLIENT_ID,      META_PROP_VALUE_INVALID, complain_about_broken_client, NONE },
-    { display->atom_WM_WINDOW_ROLE,    META_PROP_VALUE_STRING, reload_wm_window_role, LOAD_INIT },
-    { display->atom__NET_WM_WINDOW_TYPE, META_PROP_VALUE_ATOM_LIST, reload_net_wm_window_type, LOAD_INIT | 
INCLUDE_OR },
+    { display->atom_WM_WINDOW_ROLE,    META_PROP_VALUE_STRING, reload_wm_window_role, LOAD_INIT | FORCE_INIT 
},
+    { display->atom__NET_WM_WINDOW_TYPE, META_PROP_VALUE_ATOM_LIST, reload_net_wm_window_type, LOAD_INIT | 
INCLUDE_OR | FORCE_INIT },
     { display->atom__NET_WM_STRUT,         META_PROP_VALUE_INVALID, reload_struts, NONE },
     { display->atom__NET_WM_STRUT_PARTIAL, META_PROP_VALUE_INVALID, reload_struts, NONE },
     { display->atom__NET_WM_BYPASS_COMPOSITOR, META_PROP_VALUE_CARDINAL,  reload_bypass_compositor, NONE },
@@ -1826,6 +1828,9 @@ meta_display_init_window_prop_hooks (MetaDisplay *display)
       /* Doing initial loading doesn't make sense if we just want notification */
       g_assert (!((cursor->flags & LOAD_INIT) && cursor->type == META_PROP_VALUE_INVALID));
 
+      /* Forcing initialization doesn't make sense if not loading initially */
+      g_assert ((cursor->flags & LOAD_INIT) || !(cursor->flags & FORCE_INIT));
+
       /* Atoms are safe to use with GINT_TO_POINTER because it's safe with
        * anything 32 bits or less, and atoms are 32 bits with the top three
        * bits clear.  (Scheifler & Gettys, 2e, p372)