Merge pull request #1480 from indridieinarsson/pr_fix_cache_bust

fix(backend): delete cached imap responses for servers that don't support SORT extension

Author: kroky

modules/imap/hm-imap-cache.php

@@ -12,6 +12,23 @@
  */
 class Hm_IMAP_Cache extends Hm_IMAP_Parser {
 
+    /**
+     * Store the imap command used to fetch a sorted message list in absence of
+     * the SORT imap extension. This needs to be removed from cache in some cases.
+     */
+    public function set_fetch_command($newval){
+        $newval = str_replace(array("\r", "\n"), array(''), preg_replace("/^A\d+ /", '', $newval));
+        $this->cache_data['INTERNAL_CYPHT_USE']['SORT_BY_FETCH'] = $newval;
+    }
+    public function get_fetch_command(){
+        if (isset($this->cache_data['INTERNAL_CYPHT_USE'])){
+            if (isset($this->cache_data['INTERNAL_CYPHT_USE']['SORT_BY_FETCH'])){
+                return $this->cache_data['INTERNAL_CYPHT_USE']['SORT_BY_FETCH'];
+            }
+        }
+        return false;
+    }
+
     /**
      * update the cache untagged QRESYNC FETCH responses
      * @param array $data low level parsed IMAP response segment
@@ -273,6 +290,12 @@ public function bust_cache($type, $full=true) {
                                 unset($this->cache_data[$type][$command]);
                                 $this->debug[] = 'Partial cache flush: '.$command;
                             }
+                            if ($this->get_fetch_command()) {
+                                if (mb_strstr($command, $this->get_fetch_command())){
+                                    unset($this->cache_data[$type][$command]);
+                                    $this->debug[] = 'Partial cache flush: '.$command;
+                                }
+                            }
                         }
                     }
                     else {

modules/imap/hm-imap.php

@@ -1653,6 +1653,7 @@ public function sort_by_fetch($sort, $reverse, $filter, $uid_str=false) {
             }
             $command = $command1.$command2;
             $cache_command = $command.(string)$reverse;
+            $this->set_fetch_command($cache_command);
             $cache = $this->check_cache($cache_command);
             if ($cache !== false) {
                 return $cache;