[evolution-mapi] Listen for ESource changes only after source-registry backend is populated

[Milan Crha <mcrha src gnome org>]

commit 002361d4b37e61ab739dfa1b3428627bdb41591e
Author: Milan Crha <mcrha redhat com>
Date:   Thu Sep 3 19:08:04 2015 +0200

    Listen for ESource changes only after source-registry backend is populated
    
    This helps to avoid unnecessary updates on the source-registry side.

 src/collection/e-mapi-backend.c |   15 +++++++++++----
 1 files changed, 11 insertions(+), 4 deletions(-)
---
diff --git a/src/collection/e-mapi-backend.c b/src/collection/e-mapi-backend.c
index 2a732da..1769556 100644
--- a/src/collection/e-mapi-backend.c
+++ b/src/collection/e-mapi-backend.c
@@ -39,6 +39,7 @@ struct _EMapiBackendPrivate {
        GHashTable *folders;
 
        gboolean need_update_folders;
+       gulong source_changed_handler_id;
 
        GMutex credentials_lock;
        ENamedParameters *credentials;
@@ -435,10 +436,6 @@ mapi_backend_constructed (GObject *object)
         *     of weird races with clients trying to create folders. */
        e_server_side_source_set_remote_creatable (
                E_SERVER_SIDE_SOURCE (source), TRUE);
-
-       g_signal_connect (
-               source, "changed",
-               G_CALLBACK (mapi_backend_source_changed_cb), backend);
 }
 
 static void
@@ -450,6 +447,11 @@ mapi_backend_dispose (GObject *object)
 
        g_hash_table_remove_all (priv->folders);
 
+       if (priv->source_changed_handler_id) {
+               g_signal_handler_disconnect (e_backend_get_source (E_BACKEND (object)), 
priv->source_changed_handler_id);
+               priv->source_changed_handler_id = 0;
+       }
+
        /* Chain up to parent's dispose() method. */
        G_OBJECT_CLASS (e_mapi_backend_parent_class)->dispose (object);
 }
@@ -484,6 +486,11 @@ mapi_backend_populate (ECollectionBackend *backend)
        if (!e_source_get_enabled (source))
                return;
 
+       if (!mapi_backend->priv->source_changed_handler_id)
+               mapi_backend->priv->source_changed_handler_id = g_signal_connect (
+                       source, "changed",
+                       G_CALLBACK (mapi_backend_source_changed_cb), backend);
+
        /* We test authentication passwords by attempting to synchronize
         * the folder hierarchy.  Since we want to synchronize the folder
         * hierarchy immediately on startup, schedule an authentication