Fix legacy_plugin so it works with assets_path/assets_dir

and also when css/js file URLs do not contain cache buster

plugins/legacy_browser/legacy_browser.php

@@ -28,14 +28,26 @@ class legacy_browser extends rcube_plugin
 
     function send_page($args)
     {
+        $p1 = $this->rc->output->asset_url('program/js');
+        $p2 = $this->rc->output->asset_url('plugins/legacy_browser/js');
+
+        $assets_dir = $this->rc->config->get('assets_dir');
+
         $ts1 = filemtime($this->home . '/js/jquery.min.js');
         $ts2 = filemtime($this->home . '/js/iehacks.js');
 
+        if (!$ts1 && $assets_dir) {
+            $ts1 = filemtime($assets_dir . '/plugins/legacy_browser/js/jquery.min.js');
+        }
+        if (!$ts2 && $assets_dir) {
+            $ts2 = filemtime($assets_dir . '/plugins/legacy_browser/js/iehacks.js');
+        }
+
         // put iehacks.js after app.js
         if ($this->rc->output->browser->ie) {
             $args['content'] = preg_replace(
-                '|(<script src="program/js/app(\.min)?\.js\?s=[0-9]+" type="text/javascript"></script>)|',
-                '\\1<script src="plugins/legacy_browser/js/iehacks.js?s=' . $ts2 . '" type="text/javascript"></script>',
+                '|(<script src="' . preg_quote($p1, '|') . '/app(\.min)?\.js(\?s=[0-9]+)?" type="text/javascript"></script>)|',
+                '\\1<script src="' . $p2 . '/iehacks.js?s=' . $ts2 . '" type="text/javascript"></script>',
                 $args['content'], 1, $count);
         }
         else {
@@ -44,10 +56,10 @@ class legacy_browser extends rcube_plugin
 
         // replace jQuery 2.x with 1.x
         $args['content'] = preg_replace(
-            '|<script src="program/js/jquery\.min\.js\?s=[0-9]+" type="text/javascript"></script>|',
-            '<script src="plugins/legacy_browser/js/jquery.min.js?s=' . $ts1 . '" type="text/javascript"></script>'
+            '|<script src="' . preg_quote($p1, '|') . '/jquery\.min\.js(\?s=[0-9]+)?" type="text/javascript"></script>|',
+            '<script src="' . $p2 . '/jquery.min.js?s=' . $ts1 . '" type="text/javascript"></script>'
             // add iehacks.js if it is IE and it wasn't added yet
-            . ($count ? '' : "\n".'<script src="plugins/legacy_browser/js/iehacks.js?s=' . $ts2 . '" type="text/javascript"></script>'),
+            . ($count ? '' : "\n".'<script src="' . $p2 . '/iehacks.js?s=' . $ts2 . '" type="text/javascript"></script>'),
             $args['content'], 1);
 
         return $args;