[folks] tests: Selectively unset D-Bus environment variables

[Philip Withnall <pwithnall src gnome org>]

commit d98b0903df5a5a76e9897c1cf82f8417268cc7b8
Author: Philip Withnall <philip tecnocode co uk>
Date:   Sun Feb 16 18:16:48 2014 +0000

    tests: Selectively unset D-Bus environment variables
    
    Don’t always unset all D-Bus environment variables when starting up or
    shutting down an isolated bus, as to do so might trample on other
    FolksTestDBus instances for other kinds of bus (e.g. session vs. system).
    
    Instead, always unset a few common environment variables (like DISPLAY),
    but only unset the DBUS_*_BUS_ADDRESS variable corresponding to the type
    of bus being start up or shut down.
    
    This is a tweaked version of the patch from
    bug: https://bugzilla.gnome.org/show_bug.cgi?id=712148

 tests/lib/gtestdbus.c |   58 +++++++++++++++++++++++++++++++++++++++++++-----
 1 files changed, 52 insertions(+), 6 deletions(-)
---
diff --git a/tests/lib/gtestdbus.c b/tests/lib/gtestdbus.c
index fed3e37..a7c1f7a 100644
--- a/tests/lib/gtestdbus.c
+++ b/tests/lib/gtestdbus.c
@@ -696,6 +696,36 @@ stop_daemon (FolksTestDBus *self)
   self->priv->bus_address = NULL;
 }
 
+static void
+common_envar_unset (void)
+{
+  /* Always want to unset the starter address since we don't support simulating
+   * auto-launched buses */
+  g_unsetenv ("DISPLAY");
+  g_unsetenv ("DBUS_STARTER_ADDRESS");
+  g_unsetenv ("DBUS_STARTER_BUS_TYPE");
+}
+
+static void
+partial_envar_unset (GBusType bus_type)
+{
+  common_envar_unset ();
+
+  switch (bus_type)
+    {
+      case G_BUS_TYPE_SESSION:
+        g_unsetenv ("DBUS_SESSION_BUS_ADDRESS");
+        break;
+      case G_BUS_TYPE_SYSTEM:
+        g_unsetenv ("DBUS_SYSTEM_BUS_ADDRESS");
+        break;
+      case G_BUS_TYPE_STARTER:
+      case G_BUS_TYPE_NONE:
+      default:
+        break;
+    }
+}
+
 /**
  * folks_test_dbus_new:
  * @flags: a #FolksTestDBusFlags
@@ -773,16 +803,23 @@ folks_test_dbus_add_service_dir (FolksTestDBus *self,
  * flag was passed to folks_test_dbus_new()). After this call, it is safe for
  * unit tests to start sending messages on the session (or system) bus.
  *
- * If this function is called from setup callback of g_test_add(),
+ * If this function is called from the setup callback of g_test_add(),
  * folks_test_dbus_down() must be called in its teardown callback.
  *
  * If this function is called from unit test's main(), then folks_test_dbus_down()
  * must be called after g_test_run().
+ *
+ * As a side-effect, this function unsets the <envar>DISPLAY</envar>,
+ * <envar>DBUS_STARTER_BUS_ADDRESS</envar> and
+ * <envar>DBUS_STARTER_BUS_TYPE</envar> environment variables. It does not unset
+ * <envar>DBUS_SESSION_BUS_ADDRESS</envar> if a system bus is being spawned,
+ * and similarly for <envar>BUS_SYSTEM_BUS_ADDRESS</envar> with a session bus.
  */
 void
 folks_test_dbus_up (FolksTestDBus *self)
 {
   const gchar *envar;
+  GBusType bus_type;
 
   g_return_if_fail (FOLKS_IS_TEST_DBUS (self));
   g_return_if_fail (self->priv->bus_address == NULL);
@@ -790,7 +827,10 @@ folks_test_dbus_up (FolksTestDBus *self)
 
   start_daemon (self);
 
-  folks_test_dbus_unset ();
+  bus_type = (self->priv->flags & FOLKS_TEST_DBUS_SYSTEM_BUS) ?
+      G_BUS_TYPE_SYSTEM :
+      G_BUS_TYPE_SESSION;
+  partial_envar_unset (bus_type);
 
   envar = (self->priv->flags & FOLKS_TEST_DBUS_SYSTEM_BUS) ?
       "DBUS_SYSTEM_BUS_ADDRESS" :
@@ -830,6 +870,12 @@ folks_test_dbus_stop (FolksTestDBus *self)
  * This will wait for the singleton returned by g_bus_get() or g_bus_get_sync()
  * is destroyed. This is done to ensure that the next unit test won't get a
  * leaked singleton from this test.
+ *
+ * As a side-effect, this function unsets the <envar>DISPLAY</envar>,
+ * <envar>DBUS_STARTER_BUS_ADDRESS</envar> and
+ * <envar>DBUS_STARTER_BUS_TYPE</envar> environment variables. It does not unset
+ * <envar>DBUS_SESSION_BUS_ADDRESS</envar> if a system bus is being shut down,
+ * and similarly for <envar>BUS_SYSTEM_BUS_ADDRESS</envar> with a session bus.
  */
 void
 folks_test_dbus_down (FolksTestDBus *self)
@@ -854,7 +900,7 @@ folks_test_dbus_down (FolksTestDBus *self)
   if (connection != NULL)
     _g_object_dispose_and_wait_weak_notify (connection);
 
-  folks_test_dbus_unset ();
+  partial_envar_unset (bus_type);
   self->priv->up = FALSE;
 }
 
@@ -872,9 +918,9 @@ folks_test_dbus_down (FolksTestDBus *self)
 void
 folks_test_dbus_unset (void)
 {
-  g_unsetenv ("DISPLAY");
+  /* See also: partial_envar_unset(). */
+  common_envar_unset ();
+
   g_unsetenv ("DBUS_SESSION_BUS_ADDRESS");
   g_unsetenv ("DBUS_SYSTEM_BUS_ADDRESS");
-  g_unsetenv ("DBUS_STARTER_ADDRESS");
-  g_unsetenv ("DBUS_STARTER_BUS_TYPE");
 }