[metacity] frame: don't use XFixes if extension is not available

[Alberts Muktupāvels <muktupavels src gnome org>]

commit ef636b17547237a3b696c19a9537dce8d606825e
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Fri Mar 10 22:51:54 2017 +0200

    frame: don't use XFixes if extension is not available

 src/core/frame.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
---
diff --git a/src/core/frame.c b/src/core/frame.c
index ae588c6..8d4644d 100644
--- a/src/core/frame.c
+++ b/src/core/frame.c
@@ -51,6 +51,9 @@ update_input_shape (MetaFrame *frame)
   Display *xdisplay;
   XserverRegion region;
 
+  if (!frame->window->display->have_xfixes)
+    return;
+
   meta_frame_calc_borders (frame, &borders);
 
   rect.x = borders.invisible.left - borders.resize.left;