Fix bug where domain name was converted to lower-case even with login_lc=false (#1488593)

Conflicts:

	CHANGELOG
	program/include/rcmail.php

CHANGELOG

@@ -1,6 +1,7 @@
 CHANGELOG Roundcube Webmail
 ===========================
 
+- Fix bug where domain name was converted to lower-case even with login_lc=false (#1488593)
 - Fix lower-casing email address on replies (#1488598)
 - Fix line separator in exported messages (#1488603)
 - Fix XSS issue where plain signatures wasn't secured in HTML mode (#1488613)

config/main.inc.php.dist

@@ -219,11 +219,12 @@ $rcmail_config['use_https'] = false;
 // 0 - disabled, 1 - username and host only, 2 - username, host, password
 $rcmail_config['login_autocomplete'] = 0;
 
-// If users authentication is not case sensitive this must be enabled.
-// You can also use it to force conversion of logins to lower case.
+// Forces conversion of logins to lower case.
+// 0 - disabled, 1 - only domain part, 2 - domain and local part.
+// If users authentication is not case-sensitive this must be enabled.
 // After enabling it all user records need to be updated, e.g. with query:
 // UPDATE users SET username = LOWER(username);
-$rcmail_config['login_lc'] = false;
+$rcmail_config['login_lc'] = 0;
 
 // Includes should be interpreted as PHP files
 $rcmail_config['skin_include_php'] = false;

program/include/rcmail.php

@@ -899,7 +899,14 @@ class rcmail
     // Convert username to lowercase. If storage backend
     // is case-insensitive we need to store always the same username (#1487113)
     if ($config['login_lc']) {
-      $username = mb_strtolower($username);
+      if ($config['login_lc'] == 2 || $config['login_lc'] === true) {
+        $username = mb_strtolower($username);
+      }
+      else if (strpos($username, '@')) {
+        // lowercase domain name
+        list($local, $domain) = explode('@', $username);
+        $username = $local . '@' . mb_strtolower($domain);
+      }
     }
 
     // try to resolve email address from virtuser table
@@ -909,17 +916,13 @@ class rcmail
 
     // Here we need IDNA ASCII
     // Only rcube_contacts class is using domain names in Unicode
-    $host = rcube_idn_to_ascii($host);
-    if (strpos($username, '@')) {
-      // lowercase domain name
-      list($local, $domain) = explode('@', $username);
-      $username = $local . '@' . mb_strtolower($domain);
-      $username = rcube_idn_to_ascii($username);
-    }
+    $host     = rcube_idn_to_ascii($host);
+    $username = rcube_idn_to_ascii($username);
 
     // user already registered -> overwrite username
-    if ($user = rcube_user::query($username, $host))
+    if ($user = rcube_user::query($username, $host)) {
       $username = $user->data['username'];
+    }
 
     if (!$this->storage)
       $this->storage_init();