[glib-networking] proxy: Use XDG_CURRENT_DESKTOP to determine which proxy module to load

[Michael Catanzaro <mcatanzaro src gnome org>]

commit 89c45b82b85daef0f1e679dbd15a9c7c893deb17
Author: Michael Catanzaro <mcatanzaro igalia com>
Date:   Mon Feb 12 18:28:55 2018 -0600

    proxy: Use XDG_CURRENT_DESKTOP to determine which proxy module to load
    
    This will somewhat reduce the odds that that we'll load libproxy in the
    gnome-shell greeter process, causing libproxy's old version of mozjs to
    be loaded into the same process as gjs's newer version, causing the
    login screen to crash in a spectacular loop of sadness, causing
    coredumpctl to thrash the system... yeah.
    
    This is already fixed in gnome-session by
    https://git.gnome.org/browse/gnome-session/commit/?id=5f920253dfb2c0f2c4b742690f306cfea2ac6613
    but I figure I should do my civic duty here to make it easier to remove
    these environment variables in the future.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=790387

 proxy/gnome/gproxyresolvergnome.c |   16 ++++++++--------
 proxy/tests/gnome.c               |    2 +-
 2 files changed, 9 insertions(+), 9 deletions(-)
---
diff --git a/proxy/gnome/gproxyresolvergnome.c b/proxy/gnome/gproxyresolvergnome.c
index f9dba49..c3b3a7b 100644
--- a/proxy/gnome/gproxyresolvergnome.c
+++ b/proxy/gnome/gproxyresolvergnome.c
@@ -315,17 +315,17 @@ update_settings (GProxyResolverGnome *resolver)
 static gboolean
 g_proxy_resolver_gnome_is_supported (GProxyResolver *object)
 {
-  const char *session;
+  const char *desktop;
 
-  if (g_getenv ("GNOME_DESKTOP_SESSION_ID"))
-    return TRUE;
-
-  session = g_getenv ("DESKTOP_SESSION");
-  if (session == NULL)
+  desktop = g_getenv ("XDG_CURRENT_DESKTOP");
+  if (desktop == NULL)
     return FALSE;
 
-  return g_str_has_prefix (session, "gnome") ||
-         strcmp (session, "ubuntu") == 0;
+  /* Remember that XDG_CURRENT_DESKTOP is a list of strings. Desktops that
+   * pretend to be GNOME, like Unity, add themselves here. That's fine, but
+   * if so they'd better really support our proxy settings.
+   */
+  return strstr (desktop, "GNOME") != NULL;
 }
 
 static inline gchar **
diff --git a/proxy/tests/gnome.c b/proxy/tests/gnome.c
index de91aaf..6603db3 100644
--- a/proxy/tests/gnome.c
+++ b/proxy/tests/gnome.c
@@ -163,7 +163,7 @@ main (int   argc,
   g_setenv ("GIO_EXTRA_MODULES", TOP_BUILDDIR "/proxy/gnome/.libs", TRUE);
   g_setenv ("GIO_USE_PROXY_RESOLVER", "gnome", TRUE);
   g_setenv ("GSETTINGS_BACKEND", "memory", TRUE);
-  g_setenv ("DESKTOP_SESSION", "gnome", TRUE);
+  g_setenv ("XDG_CURRENT_DESKTOP", "GNOME", TRUE);
 
   g_test_add_vtable ("/proxy/gnome/uri", 0, NULL,
                      reset_proxy_settings, test_proxy_uri, NULL);