[evolution/gnome-3-16] Bug 746276 - e_client_cache_get_client_sync() gets stuck

[Milan Crha <mcrha src gnome org>]

commit 13d5477361f81be00bceff80c7b4c0d9c60c8408
Author: Milan Crha <mcrha redhat com>
Date:   Tue Apr 14 20:37:57 2015 +0200

    Bug 746276 - e_client_cache_get_client_sync() gets stuck

 e-util/e-client-cache.c |   21 ++++++++++++++++++++-
 1 files changed, 20 insertions(+), 1 deletions(-)
---
diff --git a/e-util/e-client-cache.c b/e-util/e-client-cache.c
index 7e96715..a84e388 100644
--- a/e-util/e-client-cache.c
+++ b/e-util/e-client-cache.c
@@ -1091,6 +1091,18 @@ client_cache_get_client_sync_cb (GObject *source_object,
        g_mutex_unlock (&data->mutex);
 }
 
+static gboolean
+client_cache_unlock_data_mutex_cb (gpointer user_data)
+{
+       GetClientSyncData *data = user_data;
+
+       g_return_val_if_fail (data != NULL, FALSE);
+
+       g_mutex_unlock (&data->mutex);
+
+       return FALSE;
+}
+
 /**
  * e_client_cache_get_client_sync:
  * @client_cache: an #EClientCache
@@ -1151,6 +1163,7 @@ e_client_cache_get_client_sync (EClientCache *client_cache,
 {
        GetClientSyncData data;
        GAsyncResult *result;
+       GSource *idle_source;
        EClient *client;
 
        g_return_val_if_fail (E_IS_CLIENT_CACHE (client_cache), NULL);
@@ -1169,7 +1182,13 @@ e_client_cache_get_client_sync (EClientCache *client_cache,
           because that main context effectively dies at the end of this function. */
        data.closure = e_async_closure_new ();
 
-       g_mutex_unlock (&data.mutex);
+       /* Unlock the closure->lock in the main loop, to ensure thread safety.
+          It should be processed before anything else, otherwise deadlock happens. */
+       idle_source = g_idle_source_new ();
+       g_source_set_callback (idle_source, client_cache_unlock_data_mutex_cb, &data, NULL);
+       g_source_set_priority (idle_source, G_PRIORITY_HIGH * 2);
+       g_source_attach (idle_source, g_main_context_get_thread_default ());
+       g_source_unref (idle_source);
 
        result = e_async_closure_wait (data.closure);