[evolution-ews] I#17 - [Calendar] Retry item download on ErrorBatchProcessingStopped error

[Milan Crha <mcrha src gnome org>]

commit d0352a061ba42a32b935e1e68e627a7103c7a86e
Author: Milan Crha <mcrha redhat com>
Date:   Tue Nov 6 11:35:38 2018 +0100

    I#17 - [Calendar] Retry item download on ErrorBatchProcessingStopped error
    
    Closes https://gitlab.gnome.org/GNOME/evolution-ews/issues/17

 src/calendar/e-cal-backend-ews.c | 70 +++++++++++++++++++++++++++++++---------
 1 file changed, 54 insertions(+), 16 deletions(-)
---
diff --git a/src/calendar/e-cal-backend-ews.c b/src/calendar/e-cal-backend-ews.c
index e81da518..a9532c8a 100644
--- a/src/calendar/e-cal-backend-ews.c
+++ b/src/calendar/e-cal-backend-ews.c
@@ -1044,28 +1044,66 @@ ecb_ews_get_items_sync (ECalBackendEws *cbews,
                        GCancellable *cancellable,
                        GError **error)
 {
-       GSList *items = NULL, *link;
-       gboolean success;
+       GSList *items = NULL, *link, *retry_ids = NULL;
+       gboolean success = TRUE;
 
        g_return_val_if_fail (E_IS_CAL_BACKEND_EWS (cbews), FALSE);
        g_return_val_if_fail (out_components != NULL, FALSE);
 
-       success = e_ews_connection_get_items_sync (
-               cbews->priv->cnc,
-               EWS_PRIORITY_MEDIUM,
-               item_ids,
-               default_props,
-               add_props,
-               FALSE,
-               NULL,
-               E_EWS_BODY_TYPE_TEXT,
-               &items,
-               NULL, NULL,
-               cancellable,
-               error);
+       while (success = success && !g_cancellable_set_error_if_cancelled (cancellable, error), success) {
+               GSList *received = NULL, *new_retry_ids = NULL, *ids_link;
+
+               success = e_ews_connection_get_items_sync (
+                       cbews->priv->cnc,
+                       EWS_PRIORITY_MEDIUM,
+                       item_ids,
+                       default_props,
+                       add_props,
+                       FALSE,
+                       NULL,
+                       E_EWS_BODY_TYPE_TEXT,
+                       &received,
+                       NULL, NULL,
+                       cancellable,
+                       error);
+
+               for (link = received, ids_link = (GSList *) item_ids; success && link && ids_link; link = 
g_slist_next (link), ids_link = g_slist_next (ids_link)) {
+                       EEwsItem *item = link->data;
+
+                       if (!item)
+                               continue;
+
+                       if (e_ews_item_get_item_type (item) == E_EWS_ITEM_TYPE_ERROR) {
+                               const GError *item_error;
+
+                               item_error = e_ews_item_get_error (item);
+                               if (g_error_matches (item_error, EWS_CONNECTION_ERROR, 
EWS_CONNECTION_ERROR_BATCHPROCESSINGSTOPPED)) {
+                                       new_retry_ids = g_slist_prepend (new_retry_ids, g_strdup 
(ids_link->data));
+                                       g_object_unref (item);
+                               } else {
+                                       items = g_slist_prepend (items, item);
+                               }
+                       } else {
+                               items = g_slist_prepend (items, item);
+                       }
+               }
+
+               g_slist_free_full (retry_ids, g_free);
+               g_slist_free (received);
+               retry_ids = new_retry_ids;
+
+               if (!retry_ids)
+                       break;
+
+               item_ids = retry_ids;
+       }
+
+       g_slist_free_full (retry_ids, g_free);
+
+       items = g_slist_reverse (items);
 
        if (!success)
-               return FALSE;
+               goto exit;
 
        /* fetch modified occurrences */
        for (link = items; link; link = g_slist_next (link)) {