[gimp] do not crash on fonts with 000 permissions.

[Simon Budig <simon src gnome org>]

commit 1bbf9ca4409905d3761c751667ec03d6ef6a059b
Author: Simon Budig <simon budig de>
Date:   Wed Jun 6 01:15:19 2012 +0200

    do not crash on fonts with 000 permissions.

 app/text/gimpfont.c |    1 +
 1 files changed, 1 insertions(+), 0 deletions(-)
---
diff --git a/app/text/gimpfont.c b/app/text/gimpfont.c
index 8bd40ec..ccd443b 100644
--- a/app/text/gimpfont.c
+++ b/app/text/gimpfont.c
@@ -638,6 +638,7 @@ gimp_font_get_sample_string (PangoContext         *context,
   g_return_val_if_fail (PANGO_IS_FC_FONT (font), "Aa");
 
   face = pango_fc_font_lock_face (PANGO_FC_FONT (font));
+  g_return_val_if_fail (face != NULL, "Aa");
   ot_info = pango_ot_info_get (face);
 
   /* First check what script(s), if any, the font has GSUB or GPOS