[glib] gkeyfile: Fix FD validity test to be technically correct

[Philip Withnall <pwithnall src gnome org>]

commit fc857073a01d2fcc0e5f0ec3ad0fe9baecc6fb69
Author: Stewart Brodie <stewart eh org>
Date:   Fri Jan 8 14:35:00 2016 +0000

    gkeyfile: Fix FD validity test to be technically correct
    
    The fd could be valid and zero.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=760324

 glib/gkeyfile.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/glib/gkeyfile.c b/glib/gkeyfile.c
index 732e05b..05367df 100644
--- a/glib/gkeyfile.c
+++ b/glib/gkeyfile.c
@@ -789,7 +789,7 @@ find_file_in_data_dirs (const gchar   *file,
                              "found in search dirs"));
     }
 
-  if (output_file != NULL && fd > 0)
+  if (output_file != NULL && fd != -1)
     *output_file = g_strdup (path);
 
   g_free (path);