If git's author name does not contain valid utf-8 bytes, skip the author

lookup in the database, which would otherwise only bring up errors.

NEWS.mdtext

@@ -33,6 +33,8 @@ or newer to properly run this version of Indefero!
   ATTENTION: This needs Pluf 46b7f251 or newer!
 - Fix the branch links users of the Subversion frontend get when they enter a wrong revision
   and only display this list if there are any branches available for all SCMs
+- If git's author name is not encoded in an UTF-8 compatible encoding, skip the author lookup,
+  as we have no information what the author string is actually encoded in
 
 ## Documentation
 

src/IDF/Scm/Git.php

@@ -346,6 +346,14 @@ class IDF_Scm_Git extends IDF_Scm
         if (!preg_match('/<(.*)>/', $author, $match)) {
             return null;
         }
+        // FIXME: newer git versions know a i18n.commitencoding setting which
+        // leads to another header, "encoding", with which we _could_ try to
+        // decode the string into utf8. Unfortunately this does not always
+        // work, especially not in older repos, so we would then still have
+        // to supply some fallback.
+        if (!mb_check_encoding($match[1], 'UTF-8')) {
+            return null;
+        }
         $sql = new Pluf_SQL('login=%s', array($match[1]));
         $users = Pluf::factory('Pluf_User')->getList(array('filter'=>$sql->gen()));
         if ($users->count() > 0) {