[evolution-data-server] Bug #711436 - CalDAV: Ignore ctag on manual Refresh invocation

[Milan Crha <mcrha src gnome org>]

commit b1789dd2c98fe8c0bc5fb885d018489d05557d49
Author: Milan Crha <mcrha redhat com>
Date:   Fri Mar 7 12:03:11 2014 +0100

    Bug #711436 - CalDAV: Ignore ctag on manual Refresh invocation

 calendar/backends/caldav/e-cal-backend-caldav.c |   26 ++++++++++++++++------
 1 files changed, 19 insertions(+), 7 deletions(-)
---
diff --git a/calendar/backends/caldav/e-cal-backend-caldav.c b/calendar/backends/caldav/e-cal-backend-caldav.c
index c2fde31..f0f84b8 100644
--- a/calendar/backends/caldav/e-cal-backend-caldav.c
+++ b/calendar/backends/caldav/e-cal-backend-caldav.c
@@ -58,6 +58,7 @@ typedef enum {
 
        SLAVE_SHOULD_SLEEP,
        SLAVE_SHOULD_WORK,
+       SLAVE_SHOULD_WORK_NO_CTAG_CHECK,
        SLAVE_SHOULD_DIE
 
 } SlaveCommand;
@@ -1320,7 +1321,8 @@ compat_libxml_output_buffer_get_content (xmlOutputBufferPtr buf,
 /* Returns whether calendar changed on the server. This works only when server
  * supports 'getctag' extension. */
 static gboolean
-check_calendar_changed_on_server (ECalBackendCalDAV *cbdav)
+check_calendar_changed_on_server (ECalBackendCalDAV *cbdav,
+                                 gboolean save_ctag)
 {
        xmlOutputBufferPtr        buf;
        SoupMessage              *message;
@@ -1395,7 +1397,7 @@ check_calendar_changed_on_server (ECalBackendCalDAV *cbdav)
                        if (ctag && my_ctag && g_str_equal (ctag, my_ctag)) {
                                /* ctag is same, no change in the calendar */
                                result = FALSE;
-                       } else {
+                       } else if (save_ctag) {
                                /* do not store ctag now, do it rather after complete sync */
                                g_free (cbdav->priv->ctag_to_store);
                                cbdav->priv->ctag_to_store = ctag;
@@ -2264,7 +2266,8 @@ free_comp_list (gpointer cclist)
 static void
 synchronize_cache (ECalBackendCalDAV *cbdav,
                    time_t start_time,
-                   time_t end_time)
+                   time_t end_time,
+                  gboolean can_check_ctag)
 {
        CalDAVObject *sobjs, *object;
        GSList *c_objs, *c_iter; /* list of all items known from our cache */
@@ -2273,7 +2276,10 @@ synchronize_cache (ECalBackendCalDAV *cbdav,
        GSList *hrefs_to_update, *htu; /* list of href-s to update */
        gint i, len;
 
-       if (!check_calendar_changed_on_server (cbdav)) {
+       /* intentionally do server-side checking first, and then the bool test,
+          to store actual ctag value first, and then update the content, to not
+          do it again the next time this function is called */
+       if (!check_calendar_changed_on_server (cbdav, start_time == (time_t) 0) && can_check_ctag) {
                /* no changes on the server, no update required */
                return;
        }
@@ -2528,6 +2534,8 @@ caldav_synch_slave_loop (gpointer data)
        know_unreachable = !cbdav->priv->opened;
 
        while (cbdav->priv->slave_cmd != SLAVE_SHOULD_DIE) {
+               gboolean can_check_ctag = TRUE;
+
                if (cbdav->priv->slave_cmd == SLAVE_SHOULD_SLEEP) {
                        /* just sleep until we get woken up again */
                        g_cond_wait (&cbdav->priv->cond, &cbdav->priv->busy_lock);
@@ -2540,6 +2548,10 @@ caldav_synch_slave_loop (gpointer data)
                 * Synch it baby one more time ...
                 */
                cbdav->priv->slave_busy = TRUE;
+               if (cbdav->priv->slave_cmd == SLAVE_SHOULD_WORK_NO_CTAG_CHECK) {
+                       cbdav->priv->slave_cmd = SLAVE_SHOULD_WORK;
+                       can_check_ctag = FALSE;
+               }
 
                if (!cbdav->priv->opened) {
                        gboolean server_unreachable = FALSE;
@@ -2580,11 +2592,11 @@ caldav_synch_slave_loop (gpointer data)
                        time (&now);
                        /* check for events in the month before/after today first,
                         * to show user actual data as soon as possible */
-                       synchronize_cache (cbdav, time_add_week_with_zone (now, -5, utc), 
time_add_week_with_zone (now, +5, utc));
+                       synchronize_cache (cbdav, time_add_week_with_zone (now, -5, utc), 
time_add_week_with_zone (now, +5, utc), can_check_ctag);
 
                        if (cbdav->priv->slave_cmd != SLAVE_SHOULD_SLEEP) {
                                /* and then check for changes in a whole calendar */
-                               synchronize_cache (cbdav, 0, 0);
+                               synchronize_cache (cbdav, 0, 0, can_check_ctag);
                        }
 
                        if (caldav_debug_show (DEBUG_SERVER_ITEMS)) {
@@ -3017,7 +3029,7 @@ caldav_refresh (ECalBackendSync *backend,
                return;
        }
 
-       update_slave_cmd (cbdav->priv, SLAVE_SHOULD_WORK);
+       update_slave_cmd (cbdav->priv, SLAVE_SHOULD_WORK_NO_CTAG_CHECK);
 
        /* wake it up */
        g_cond_signal (&cbdav->priv->cond);