[gdm] data: fall back to old greeter if gnome-shell not installed

[Ray Strode <halfline src gnome org>]

commit 18b0eb0a6307600476d0af5e206e13466b4a1040
Author: Ray Strode <rstrode redhat com>
Date:   Tue Sep 4 22:31:15 2012 -0400

    data: fall back to old greeter if gnome-shell not installed
    
    Some users use GDM without having gnome-shell installed. Upon
    booting, the screen stays black and those users aren't able to
    log in at all.
    
    What should happen: GDM should recognize this case and use its
    fallback mode.
    
    This commit fixes that.  Suggestion by Jeremy Bicha.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=683069

 data/gdm-shell.session.in |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/data/gdm-shell.session.in b/data/gdm-shell.session.in
index 388f80c..1bea43c 100644
--- a/data/gdm-shell.session.in
+++ b/data/gdm-shell.session.in
@@ -1,5 +1,5 @@
 [GNOME Session]
 Name=Display Manager
 RequiredComponents=gnome-shell;gnome-settings-daemon;
-IsRunnableHelper= CHECK_ACCELERATED_DIR@/gnome-session-check-accelerated
+IsRunnableHelper=bash -c 'type -p gnome-shell >& /dev/null && @CHECK_ACCELERATED_DIR@/gnome-session-check-accelerated'
 FallbackSession=gdm-fallback