[mutter] window: Don't try to auto-maximize when headless

[Jonas Ådahl <jadahl src gnome org>]

commit 6dd819a61e94023bf05b0a91c42a4c27f63eb2d9
Author: Jonas Ådahl <jadahl gmail com>
Date:   Mon Sep 25 14:11:22 2017 -0400

    window: Don't try to auto-maximize when headless
    
    Automatic maximization is done when a window is almost the size of the
    work area of a monitor. This makes no sense to try when there is no
    monitor available, so skip trying to do this when headless.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=787637

 src/core/window.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)
---
diff --git a/src/core/window.c b/src/core/window.c
index d3c0fa5..552e8c4 100644
--- a/src/core/window.c
+++ b/src/core/window.c
@@ -2361,7 +2361,10 @@ meta_window_show (MetaWindow *window)
 
   if (!window->placed)
     {
-      if (meta_prefs_get_auto_maximize() && window->showing_for_first_time && window->has_maximize_func)
+      if (window->monitor &&
+          meta_prefs_get_auto_maximize() &&
+          window->showing_for_first_time &&
+          window->has_maximize_func)
         {
           MetaRectangle work_area;
           meta_window_get_work_area_for_monitor (window, window->monitor->number, &work_area);