[evolution-data-server] Bug 769834 - [IMAPx] Minimize bandwidth usage on metered networks

[Milan Crha <mcrha src gnome org>]

commit fdf9e66e837474893f02ce08d33ae032b28f94e3
Author: Milan Crha <mcrha redhat com>
Date:   Mon Sep 11 16:18:56 2017 +0200

    Bug 769834 - [IMAPx] Minimize bandwidth usage on metered networks

 src/camel/providers/imapx/camel-imapx-server.c |   32 +++++++++++++++++++++--
 1 files changed, 29 insertions(+), 3 deletions(-)
---
diff --git a/src/camel/providers/imapx/camel-imapx-server.c b/src/camel/providers/imapx/camel-imapx-server.c
index adcbc01..14a8a51 100644
--- a/src/camel/providers/imapx/camel-imapx-server.c
+++ b/src/camel/providers/imapx/camel-imapx-server.c
@@ -4952,6 +4952,30 @@ imapx_server_fetch_changes (CamelIMAPXServer *is,
        return success;
 }
 
+static gboolean
+camel_imapx_server_skip_old_flags_update (CamelStore *store)
+{
+       CamelSession *session;
+       GNetworkMonitor *network_monitor;
+       gboolean skip_old_flags_update = FALSE;
+
+       if (!CAMEL_IS_STORE (store))
+               return FALSE;
+
+       session = camel_service_ref_session (CAMEL_SERVICE (store));
+       if (!session)
+               return skip_old_flags_update;
+
+       network_monitor = camel_session_ref_network_monitor (session);
+
+       skip_old_flags_update = network_monitor && g_network_monitor_get_network_metered (network_monitor);
+
+       g_clear_object (&network_monitor);
+       g_clear_object (&session);
+
+       return skip_old_flags_update;
+}
+
 gboolean
 camel_imapx_server_refresh_info_sync (CamelIMAPXServer *is,
                                      CamelIMAPXMailbox *mailbox,
@@ -4971,7 +4995,7 @@ camel_imapx_server_refresh_info_sync (CamelIMAPXServer *is,
        guint64 highestmodseq;
        guint32 total;
        guint64 uidl;
-       gboolean need_rescan;
+       gboolean need_rescan, skip_old_flags_update;
        gboolean success;
 
        g_return_val_if_fail (CAMEL_IS_IMAPX_SERVER (is), FALSE);
@@ -5074,8 +5098,10 @@ camel_imapx_server_refresh_info_sync (CamelIMAPXServer *is,
 
        known_uids = g_hash_table_new_full (g_str_hash, g_str_equal, (GDestroyNotify) camel_pstring_free, 
NULL);
 
+       skip_old_flags_update = camel_imapx_server_skip_old_flags_update (camel_folder_get_parent_store 
(folder));
+
        success = imapx_server_fetch_changes (is, mailbox, folder, known_uids, uidl, 0, cancellable, error);
-       if (success && uidl != 1)
+       if (success && uidl != 1 && !skip_old_flags_update)
                success = imapx_server_fetch_changes (is, mailbox, folder, known_uids, 0, uidl, cancellable, 
error);
 
        if (success) {
@@ -5092,7 +5118,7 @@ camel_imapx_server_refresh_info_sync (CamelIMAPXServer *is,
 
        g_mutex_unlock (&is->priv->changes_lock);
 
-       if (success) {
+       if (success && !skip_old_flags_update) {
                GList *removed = NULL;
                GPtrArray *array;
                gint ii;