[evolution-mapi] eds-I#208 - Avoid race condition when refreshing collection backend

[Milan Crha <mcrha src gnome org>]

commit 631dc530626a4aea963164d020af1bce33dc6234
Author: Milan Crha <mcrha redhat com>
Date:   Fri Aug 28 14:24:23 2020 +0200

    eds-I#208 - Avoid race condition when refreshing collection backend
    
    Related to https://gitlab.gnome.org/GNOME/evolution-data-server/-/issues/208

 src/collection/e-mapi-backend.c | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
---
diff --git a/src/collection/e-mapi-backend.c b/src/collection/e-mapi-backend.c
index 3b6f4b1..017781d 100644
--- a/src/collection/e-mapi-backend.c
+++ b/src/collection/e-mapi-backend.c
@@ -391,6 +391,8 @@ mapi_backend_sync_folders_idle_cb (gpointer user_data)
        g_list_free_full (configured, g_object_unref);
        g_object_unref (server);
 
+       e_collection_backend_thaw_populate (E_COLLECTION_BACKEND (backend));
+
        return FALSE;
 }
 
@@ -409,7 +411,11 @@ mapi_backend_queue_auth_session (EMapiBackend *backend)
                sfd->backend = g_object_ref (backend);
                sfd->profile = camel_mapi_settings_dup_profile (mapi_settings);
 
+               /* Needed, because the mapi_backend_sync_folders_idle_cb() calls 'thaw' */
+               e_collection_backend_freeze_populate (E_COLLECTION_BACKEND (backend));
+
                mapi_backend_sync_folders_idle_cb (sfd);
+
                sync_folders_data_free (sfd);
 
                return;
@@ -508,6 +514,11 @@ mapi_backend_populate (ECollectionBackend *backend)
        if (!e_source_get_enabled (source))
                return;
 
+       if (!e_collection_backend_freeze_populate (backend)) {
+               e_collection_backend_thaw_populate (backend);
+               return;
+       }
+
        if (!mapi_backend->priv->source_changed_handler_id)
                mapi_backend->priv->source_changed_handler_id = g_signal_connect (
                        source, "changed",
@@ -518,6 +529,8 @@ mapi_backend_populate (ECollectionBackend *backend)
         * hierarchy immediately on startup, schedule an authentication
         * session first thing. */
        mapi_backend_queue_auth_session (mapi_backend);
+
+       e_collection_backend_thaw_populate (backend);
 }
 
 static gchar *
@@ -855,10 +868,13 @@ mapi_backend_authenticate_sync (EBackend *backend,
        EMapiConnection *conn;
        CamelMapiSettings *settings;
        GSList *mapi_folders = NULL;
+       gboolean in_sync_folders = FALSE;
        GError *mapi_error = NULL, *krb_error = NULL;
 
        g_return_val_if_fail (E_IS_MAPI_BACKEND (backend), E_SOURCE_AUTHENTICATION_ERROR);
 
+       e_collection_backend_freeze_populate (E_COLLECTION_BACKEND (backend));
+
        mapi_backend = E_MAPI_BACKEND (backend);
        settings = mapi_backend_get_settings (mapi_backend);
 
@@ -907,6 +923,8 @@ mapi_backend_authenticate_sync (EBackend *backend,
 
                g_clear_error (&krb_error);
 
+               e_collection_backend_thaw_populate (E_COLLECTION_BACKEND (backend));
+
                return res;
        }
 
@@ -929,6 +947,8 @@ mapi_backend_authenticate_sync (EBackend *backend,
                        sync_folders_data_free);
 
                e_collection_backend_authenticate_children (E_COLLECTION_BACKEND (backend), credentials);
+
+               in_sync_folders = TRUE;
        } else {
                ESource *source = e_backend_get_source (backend);
 
@@ -942,6 +962,9 @@ mapi_backend_authenticate_sync (EBackend *backend,
        g_clear_error (&mapi_error);
        g_clear_error (&krb_error);
 
+       if (!in_sync_folders)
+               e_collection_backend_thaw_populate (E_COLLECTION_BACKEND (backend));
+
        return E_SOURCE_AUTHENTICATION_ACCEPTED;
 }