[mutter] Don't move all window to active workspace if monitors change

[Owen Taylor <otaylor src gnome org>]

commit 634b76b82c7ed07ae654d879cf0b82be9e4f2c25
Author: Alexander Larsson <alexl redhat com>
Date:   Tue Mar 22 18:04:08 2011 +0100

    Don't move all window to active workspace if monitors change
    
    https://bugzilla.gnome.org/show_bug.cgi?id=645408

 src/core/window.c |    4 ++++
 1 files changed, 4 insertions(+), 0 deletions(-)
---
diff --git a/src/core/window.c b/src/core/window.c
index 69ed017..016c48c 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -4223,9 +4223,13 @@ meta_window_update_monitor (MetaWindow *window)
        * workspace is when dropping the window on some other workspace thumbnail directly.
        * That should be handled by explicitly moving the window before changing the
        * workspace
+       * Don't do this if old == NULL, because thats what happens when we're updating
+       * the monitors due to a monitors change event, and we don't want to move
+       * everything to the currently active workspace.
        */
       if (meta_prefs_get_workspaces_only_on_primary () &&
           meta_window_is_on_primary_monitor (window)  &&
+          old != NULL &&
           window->screen->active_workspace != window->workspace)
         meta_window_change_workspace (window, window->screen->active_workspace);