[folks] tests: Don’t close stdout for dbus-daemon in GTestDBus

[Philip Withnall <pwithnall src gnome org>]

commit f974cd245a753f9d7e5f0c63beb8f8be77cb5cc7
Author: Philip Withnall <philip tecnocode co uk>
Date:   Sat Jun 21 20:29:57 2014 +0100

    tests: Don’t close stdout for dbus-daemon in GTestDBus
    
    The stdout FD passed to dbus-daemon is propagated to all its child
    processes, such as service activated processes. If we close the FD after
    reading the bus address from the daemon, any child process which
    subsequently writes to stdout (e.g. for logging) will get a SIGPIPE and
    explode.
    
    Instead of closing the stdout FD immediately after dbus-daemon has
    spawned, keep it open until the daemon is killed.
    
    This fixes the Tracker tests, as tracker-store writes startup
    information to stdout.

 tests/lib/gtestdbus.c |   13 +++++++++----
 1 files changed, 9 insertions(+), 4 deletions(-)
---
diff --git a/tests/lib/gtestdbus.c b/tests/lib/gtestdbus.c
index 38895ff..498100b 100644
--- a/tests/lib/gtestdbus.c
+++ b/tests/lib/gtestdbus.c
@@ -444,6 +444,7 @@ struct _FolksTestDBusPrivate
   FolksTestDBusFlags flags;
   GPtrArray *service_dirs;
   GPid bus_pid;
+  gint bus_stdout_fd;
   gchar *bus_address;
   gboolean up;
 };
@@ -618,7 +619,6 @@ start_daemon (FolksTestDBus *self)
   const gchar *argv[] = {"dbus-daemon", "--print-address", "--config-file=foo", NULL};
   gchar *config_path;
   gchar *config_arg;
-  gint stdout_fd;
   GIOChannel *channel;
   gsize termpos;
   GError *error = NULL;
@@ -644,15 +644,18 @@ start_daemon (FolksTestDBus *self)
                             NULL,
                             &self->priv->bus_pid,
                             NULL,
-                            &stdout_fd,
+                            &self->priv->bus_stdout_fd,
                             NULL,
                             &error);
   g_assert_no_error (error);
 
   _folks_test_watcher_add_pid (self->priv->bus_pid);
 
-  /* Read bus address from daemon' stdout */
-  channel = g_io_channel_unix_new (stdout_fd);
+  /* Read bus address from daemon' stdout. We have to be careful to avoid
+   * closing the FD, as it is passed to any D-Bus service activated processes,
+   * and if we close it, they will get a SIGPIPE and die when they try to write
+   * to their stdout. */
+  channel = g_io_channel_unix_new (dup (self->priv->bus_stdout_fd));
   g_io_channel_read_line (channel, &self->priv->bus_address, NULL,
       &termpos, &error);
   g_assert_no_error (error);
@@ -696,6 +699,8 @@ stop_daemon (FolksTestDBus *self)
   _folks_test_watcher_remove_pid (self->priv->bus_pid);
   g_spawn_close_pid (self->priv->bus_pid);
   self->priv->bus_pid = 0;
+  close (self->priv->bus_stdout_fd);
+  self->priv->bus_stdout_fd = -1;
 
   g_free (self->priv->bus_address);
   self->priv->bus_address = NULL;