[gupnp-dlna] Use safer versions of environment variable getters.

[Jens Georg <jensgeorg src gnome org>]

commit 8ea70d05e506ef7f5a5b54208539250d6cbf939e
Author: Krzesimir Nowak <krnowak openismus com>
Date:   Tue Dec 4 13:30:26 2012 +0100

    Use safer versions of environment variable getters.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=689616

 libgupnp-dlna/gupnp-dlna-metadata-backend.c |    9 +++++++--
 1 files changed, 7 insertions(+), 2 deletions(-)
---
diff --git a/libgupnp-dlna/gupnp-dlna-metadata-backend.c b/libgupnp-dlna/gupnp-dlna-metadata-backend.c
index 89f1b61..a19b155 100644
--- a/libgupnp-dlna/gupnp-dlna-metadata-backend.c
+++ b/libgupnp-dlna/gupnp-dlna-metadata-backend.c
@@ -35,9 +35,13 @@ load_metadata_backend (void)
         static gsize backend_chosen = 0;
 
         if (g_once_init_enter (&backend_chosen)) {
-                const gchar *backend = g_getenv ("GUPNP_DLNA_METADATA_BACKEND");
+                gchar **environment = g_get_environ ();
+                const gchar *backend =
+                               g_environ_getenv (environment,
+                                                 "GUPNP_DLNA_METADATA_BACKEND");
                 const gchar *backend_dir =
-                                   g_getenv ("GUPNP_DLNA_METADATA_BACKEND_DIR");
+                           g_environ_getenv (environment,
+                                             "GUPNP_DLNA_METADATA_BACKEND_DIR");
                 GModule *module;
                 gchar *module_path;
                 gpointer get_default_extractor = NULL;
@@ -83,6 +87,7 @@ load_metadata_backend (void)
                 g_free (module_path);
                 if (module)
                         g_module_close (module);
+                g_strfreev (environment);
                 g_once_init_leave (&backend_chosen, loaded);
         }