Fix list page reset when viewing a message in Larry skin (#1489076)

CHANGELOG

@@ -1,6 +1,7 @@
 CHANGELOG Roundcube Webmail
 ===========================
 
+- Fix list page reset when viewing a message in Larry skin (#1489076)
 - Fix min_refresh_interval handling on preferences save (#1489073)
 - Fix PDF support detection for Firefox PDF.js (#1488972)
 - Fix messages list focus issue in Internet Explorer (#1489058)

program/include/rcmail.php

@@ -98,7 +98,10 @@ class rcmail extends rcube
 
     // reset some session parameters when changing task
     if ($this->task != 'utils') {
-      if ($this->session && $_SESSION['task'] != $this->task)
+      // we reset list page when switching to another task
+      // but only to the main task interface - empty action (#1489076)
+      // this will prevent from unintentional page reset on cross-task requests
+      if ($this->session && $_SESSION['task'] != $this->task && empty($this->action))
         $this->session->remove('page');
       // set current task to session
       $_SESSION['task'] = $this->task;