[gtk+] display-x11: Unset tiled state if _GTK_EDGE_CONSTRAINTS is supported

[Timm Bäder <baedert src gnome org>]

commit 42ff22f222566448b97d4c980b91ac5f66ea9448
Author: Georges Basile Stavracas Neto <georges stavracas gmail com>
Date:   Wed Oct 4 15:33:15 2017 -0300

    display-x11: Unset tiled state if _GTK_EDGE_CONSTRAINTS is supported
    
    Commit c415bef5de introduced support for the new _GTK_EDGE_CONSTRAINTS
    atom. If the compositor supports that atom, however, we were always
    setting the tiled state, even if no actual tiling information is
    available, where the correct action is to completely remove any traces
    of the tiled state.
    
    Fix that by correctly removing the tiled state when compositor supports
    _GTK_EDGE_CONSTRAINTS Xatom.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=788516

 gdk/x11/gdkdisplay-x11.c |    6 ++----
 1 files changed, 2 insertions(+), 4 deletions(-)
---
diff --git a/gdk/x11/gdkdisplay-x11.c b/gdk/x11/gdkdisplay-x11.c
index fedfada..84a1b2f 100644
--- a/gdk/x11/gdkdisplay-x11.c
+++ b/gdk/x11/gdkdisplay-x11.c
@@ -236,10 +236,8 @@ do_edge_constraint_state_check (GdkWindow      *window,
     }
   else
     {
-      if (!(old_state & GDK_WINDOW_STATE_TILED))
-        {
-          local_set |= GDK_WINDOW_STATE_TILED;
-        }
+      if (old_state & GDK_WINDOW_STATE_TILED)
+        local_unset |= GDK_WINDOW_STATE_TILED;
     }
 
   /* Top edge */