[gnome-session] main: fix starting gnome session via startx

[Andreas Henriksson <ah src gnome org>]

commit 890a797a2b6c26e752fa74a09d9521bea913c621
Author: Andreas Henriksson <andreas fatal se>
Date:   Wed Mar 30 18:49:15 2016 +0200

    main: fix starting gnome session via startx
    
    The changes related to gsm_util_setenv during 3.19.x seems to have
    broken starting a gnome desktop the old fashioned way, eg. via startx.
    
    The gnome.session required components has OnlyShowIn=GNOME; which
    disqualifies them from being started unless XDG_CURRENT_DESKTOP is also
    set to GNOME (by the gio utility function used to look up info).
    
    Currently gnome-session already carries code to catch the case of
    XDG_CURRENT_DESKTOP being unset and set it to GNOME as a fallback.
    Unfortunately the changes to gsm_util_setenv seems to have made it only
    set the values in the (dbus activated) child environment, rather than
    the current environment which g_desktop_app_info_get_show_in is looking
    at.
    
    Make the fallback code set XDG_CURRENT_DESKTOP in both current
    and child environment fixes it.
    Also move the entire hunk of code before initializing gio to
    prevent potential thread issues, now that is uses g_setenv.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=764379

 gnome-session/main.c |   16 +++++++++-------
 1 files changed, 9 insertions(+), 7 deletions(-)
---
diff --git a/gnome-session/main.c b/gnome-session/main.c
index 14b201b..9f3ca0f 100644
--- a/gnome-session/main.c
+++ b/gnome-session/main.c
@@ -292,6 +292,15 @@ main (int argc, char **argv)
                 gsm_util_init_error (TRUE, "%s", error->message);
         }
 
+        /* From 3.14 GDM sets XDG_CURRENT_DESKTOP. For compatibility with
+         * older versions of GDM,  other display managers, and startx,
+         * set a fallback value if we don't find it set.
+         */
+        if (g_getenv ("XDG_CURRENT_DESKTOP") == NULL) {
+            g_setenv("XDG_CURRENT_DESKTOP", "GNOME", TRUE);
+            gsm_util_setenv ("XDG_CURRENT_DESKTOP", "GNOME");
+        }
+
         /* Make sure we initialize gio in a way that does not autostart any daemon */
         initialize_gio ();
 
@@ -375,13 +384,6 @@ main (int argc, char **argv)
                 exit (1);
         }
 
-        /* From 3.14 GDM sets XDG_CURRENT_DESKTOP. For compatibility with
-         * older versions of GDM,  other display managers, and startx,
-         * set a fallback value if we don't find it set.
-         */
-        if (g_getenv ("XDG_CURRENT_DESKTOP") == NULL)
-            gsm_util_setenv ("XDG_CURRENT_DESKTOP", "GNOME");
-
         /* Push locale variables to dbus-daemon */
         maybe_push_env_var ("LC_TIME");
         maybe_push_env_var ("LC_NUMERIC");