gsm-util: save environment to $XDG_RUNTIME_DIR/gnome/environment

Environment variables are problematic because they require a parent
child inheritance model, but they're often used in a per-session scope.

gnome-session provides a mechanism for children to affect the
environment of future siblings via the SetEnv dbus method call.
Unfortunately that change does not affect existing siblings, or their
offspring.

This commit centralizes gnome-session's environment into a file,

     $XDG_RUNTIME_DIR/gnome/environment

so other components in the session can ensure their children get the
most up to date environment possible.

https://bugzilla.gnome.org/show_bug.cgi?id=738205

1 files changed, 35 insertions, 0 deletions

diff --git a/gnome-session/gsm-util.c b/gnome-session/gsm-util.c
index b7d2cdab..bca1b383 100644
--- a/gnome-session/gsm-util.c
+++ b/gnome-session/gsm-util.c
@@ -447,6 +447,39 @@ gsm_util_generate_startup_id (void)
                                 sequence);
 }
 
+static void
+gsm_util_save_environment (void)
+{
+        g_autoptr(GVariant)  environment = NULL;
+        g_autoptr(GError)    error = NULL;
+        g_autofree char     *environment_dir = NULL;
+        g_autofree char     *filename = NULL;
+        gconstpointer        environment_data;
+        gsize                size;
+        int                  ret;
+        gboolean             contents_set;
+
+        environment_dir = g_build_filename (g_get_user_runtime_dir (), "gnome", NULL);
+        ret = g_mkdir_with_parents (environment_dir, 0700);
+
+        if (ret < 0) {
+                g_warning ("can't create gnome runtime dir: %m");
+                return;
+        }
+
+        environment = g_variant_new_bytestring_array ((const gchar * const *) g_get_environ (), -1);
+        size = g_variant_get_size (environment);
+        environment_data = g_variant_get_data (environment);
+
+        filename = g_build_filename (environment_dir, "environment", NULL);
+
+        contents_set = g_file_set_contents (filename, environment_data, size, &error);
+
+        if (!contents_set) {
+                g_warning ("can't save environment: %s", error->message);
+        }
+}
+
 static gboolean
 gsm_util_update_activation_environment (const char  *variable,
                                         const char  *value,
@@ -511,4 +544,6 @@ gsm_util_setenv (const char *variable,
                 g_warning ("Could not make bus activated clients aware of %s=%s environment variable: %s", variable, value, bus_error->message);
                 g_error_free (bus_error);
         }
+
+        gsm_util_save_environment ();
 }