[evolution-ews] Collection backend schedules two 'populate' requests after going online

[Milan Crha <mcrha src gnome org>]

commit f50530ad101b47d461a345ff2b8b295b86c05d3a
Author: Milan Crha <mcrha redhat com>
Date:   Thu Sep 27 10:51:05 2018 +0200

    Collection backend schedules two 'populate' requests after going online
    
    ECollectionBackend base class makes sure the 'populate' method is called
    after the backend itself goes online, thus there is no need to schedule
    it in the descendant again.
    
    Related to https://gitlab.gnome.org/GNOME/evolution-data-server/issues/36

 src/collection/e-ews-backend.c | 24 +++++++++++++-----------
 1 file changed, 13 insertions(+), 11 deletions(-)
---
diff --git a/src/collection/e-ews-backend.c b/src/collection/e-ews-backend.c
index 651694b7..d9a973af 100644
--- a/src/collection/e-ews-backend.c
+++ b/src/collection/e-ews-backend.c
@@ -48,7 +48,7 @@ struct _EEwsBackendPrivate {
 
        gboolean need_update_folders;
 
-       gulong notify_online_id;
+       gulong source_changed_id;
 };
 
 struct _SyncFoldersClosure {
@@ -647,15 +647,21 @@ static void
 ews_backend_dispose (GObject *object)
 {
        EEwsBackendPrivate *priv;
+       ESource *source;
 
        priv = E_EWS_BACKEND_GET_PRIVATE (object);
 
+       source = e_backend_get_source (E_BACKEND (object));
+       if (source && priv->source_changed_id) {
+               g_signal_handler_disconnect (source, priv->source_changed_id);
+               priv->source_changed_id = 0;
+       }
+
        g_hash_table_remove_all (priv->folders);
 
-       if (priv->connection != NULL) {
-               g_object_unref (priv->connection);
-               priv->connection = NULL;
-       }
+       g_mutex_lock (&priv->connection_lock);
+       g_clear_object (&priv->connection);
+       g_mutex_unlock (&priv->connection_lock);
 
        /* Chain up to parent's dispose() method. */
        G_OBJECT_CLASS (e_ews_backend_parent_class)->dispose (object);
@@ -770,12 +776,8 @@ ews_backend_populate (ECollectionBackend *backend)
 
        ews_backend->priv->need_update_folders = TRUE;
 
-       if (!ews_backend->priv->notify_online_id) {
-               ews_backend->priv->notify_online_id = g_signal_connect (
-                       backend, "notify::online",
-                       G_CALLBACK (ews_backend_populate), NULL);
-
-               g_signal_connect (
+       if (!ews_backend->priv->source_changed_id) {
+               ews_backend->priv->source_changed_id = g_signal_connect (
                        source, "changed",
                        G_CALLBACK (ews_backend_source_changed_cb), ews_backend);
        }