[metacity] display: fix tiling when grabbing an attached dialog

[Alberts Muktupāvels <muktupavels src gnome org>]

commit 40ada015a9e04dc7a87ef1b9d2cc0b8bf6cb1f7c
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Tue Jan 20 22:41:38 2015 +0200

    display: fix tiling when grabbing an attached dialog

 src/core/display.c |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/src/core/display.c b/src/core/display.c
index e82d38e..9920936 100644
--- a/src/core/display.c
+++ b/src/core/display.c
@@ -3371,10 +3371,10 @@ meta_display_begin_grab_op (MetaDisplay *display,
   display->grab_xwindow = grab_xwindow;
   display->grab_button = button;
   display->grab_mask = modmask;
-  if (window)
+  if (grab_window)
     {
-      display->grab_tile_mode = window->tile_mode;
-      display->grab_tile_monitor_number = window->tile_monitor_number;
+      display->grab_tile_mode = grab_window->tile_mode;
+      display->grab_tile_monitor_number = grab_window->tile_monitor_number;
     }
   else
     {