[gtk/wip/chergert/quartz4u] macos: check workarea top in final check for snapping

[Christian Hergert <chergert src gnome org>]

commit f817d90d494689db77adbe9d50ac808f2a8e1489
Author: Christian Hergert <chergert redhat com>
Date:   Thu May 21 09:46:33 2020 -0700

    macos: check workarea top in final check for snapping
    
    This helps large surfaces (like from widget factory) do not let
    the CSD window fall underneath the top bar.
    
    We don't want them to end up there until we've dragged across
    monitors (which we will have a new geometry for anyway).

 gdk/macos/edgesnapping.c | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/gdk/macos/edgesnapping.c b/gdk/macos/edgesnapping.c
index e81b29626c..bf9347265a 100644
--- a/gdk/macos/edgesnapping.c
+++ b/gdk/macos/edgesnapping.c
@@ -206,6 +206,12 @@ _edge_snapping_motion (EdgeSnapping   *self,
       new_window.y = pointer_position->y - self->pointer_offset_in_window.y;
     }
 
+  /* And finally make sure we aren't underneath the top bar of the
+   * particular monitor.
+   */
+  if (Y1 (&new_window) < Y1 (&self->workarea))
+    new_window.y = self->workarea.y;
+
   *window = new_window;
 }