[mutter/gnome-3-34] window: Ignore requests to be placed on non-existent workspaces

[Florian Müllner <fmuellner src gnome org>]

commit c3d2f3f39976e1aab3481ecc6e505f114d3babd3
Author: Florian Müllner <fmuellner gnome org>
Date:   Mon Feb 3 22:58:38 2020 +0100

    window: Ignore requests to be placed on non-existent workspaces
    
    When an X11 window requests an initial workspace, we currently trust
    it that the workspace actually exists. However dynamic workspaces
    make this easy to get wrong for applications: They make it likely
    for the number of workspaces to change between application starts,
    and if the app blindly applies its saved state on startup, it will
    trigger an assertion.
    
    Make sure that we pass valid parameters to set_workspace_state(),
    and simply let the workspace assignment fall through to the default
    handling otherwise.
    
    https://gitlab.gnome.org/GNOME/mutter/issues/1029

 src/core/window.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)
---
diff --git a/src/core/window.c b/src/core/window.c
index ac8187978..a64ccb011 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -1289,7 +1289,10 @@ _meta_window_shared_new (MetaDisplay         *display,
                                                                      window->initial_workspace);
         }
 
-      set_workspace_state (window, on_all_workspaces, workspace);
+      /* Ignore when a window requests to be placed on a non-existent workspace
+       */
+      if (on_all_workspaces || workspace != NULL)
+        set_workspace_state (window, on_all_workspaces, workspace);
     }
 
   /* override-redirect windows are subtly different from other windows