[metacity] compositor-xrender: don't add shadows to ARGB windows

[Alberts Muktupāvels <muktupavels src gnome org>]

commit a6b29b2d2f6a7787c59cfffdc2bed1b5b5b99244
Author: Alberts Muktupāvels <alberts muktupavels gmail com>
Date:   Fri Oct 3 18:41:51 2014 +0300

    compositor-xrender: don't add shadows to ARGB windows

 src/compositor/compositor-xrender.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)
---
diff --git a/src/compositor/compositor-xrender.c b/src/compositor/compositor-xrender.c
index d42aa5b..012badf 100644
--- a/src/compositor/compositor-xrender.c
+++ b/src/compositor/compositor-xrender.c
@@ -903,6 +903,13 @@ window_has_shadow (MetaCompWindow *cw)
       }
     }
 
+  /* Do not add shadows to ARGB windows */
+  if (cw->mode == WINDOW_ARGB)
+    {
+      meta_verbose ("Window has no shadow as it is ARGB\n");
+      return FALSE;
+    }
+
   /* Never put a shadow around shaped windows */
   if (cw->shaped) {
     meta_verbose ("Window has no shadow as it is shaped\n");