[gnome-session/gnome-3-22] tools: Better error checking when gdk/GL fails

[Bastien Nocera <hadess src gnome org>]

commit 7e5ca1f2c7fa096073236e990dddfbb814f6675e
Author: Bastien Nocera <hadess hadess net>
Date:   Mon Oct 24 11:41:45 2016 +0200

    tools: Better error checking when gdk/GL fails
    
    See https://bugzilla.redhat.com/show_bug.cgi?id=1387898
    
    https://bugzilla.gnome.org/show_bug.cgi?id=773412

 tools/gnome-session-check-accelerated.c |    7 +++++--
 1 files changed, 5 insertions(+), 2 deletions(-)
---
diff --git a/tools/gnome-session-check-accelerated.c b/tools/gnome-session-check-accelerated.c
index 97e8dc0..b914394 100644
--- a/tools/gnome-session-check-accelerated.c
+++ b/tools/gnome-session-check-accelerated.c
@@ -147,8 +147,11 @@ main (int argc, char **argv)
          */
         if (is_discrete_gpu_check () || g_strcmp0 (g_getenv ("XDG_SESSION_TYPE"), "x11") != 0) {
                 renderer_string = get_gtk_gles_renderer ();
-                g_print ("%s", renderer_string);
-                return 0;
+                if (renderer_string) {
+                        g_print ("%s", renderer_string);
+                        return 0;
+                }
+                return 1;
         }
 
         display = gdk_display_get_default ();