diff --git a/src/applications/repository/xaction/PhabricatorRepositoryIdentityAssignTransaction.php b/src/applications/repository/xaction/PhabricatorRepositoryIdentityAssignTransaction.php
--- a/src/applications/repository/xaction/PhabricatorRepositoryIdentityAssignTransaction.php
+++ b/src/applications/repository/xaction/PhabricatorRepositoryIdentityAssignTransaction.php
@@ -52,7 +52,7 @@
     foreach ($xactions as $xaction) {
       $old = $xaction->getOldValue();
       $new = $xaction->getNewValue();
-      if (!strlen($new)) {
+      if (!phutil_nonempty_string($new)) {
         continue;
       }
 
diff --git a/src/infrastructure/storage/lisk/PhabricatorLiskDAO.php b/src/infrastructure/storage/lisk/PhabricatorLiskDAO.php
--- a/src/infrastructure/storage/lisk/PhabricatorLiskDAO.php
+++ b/src/infrastructure/storage/lisk/PhabricatorLiskDAO.php
@@ -290,7 +290,7 @@
   }
 
   protected function getUTF8StringFromStorage($string, $encoding) {
-    if ($encoding == 'utf8') {
+    if ($encoding == 'utf8' || !phutil_nonempty_string($string)) {
       return $string;
     }
 
@@ -310,7 +310,7 @@
         );
       }
 
-      $guess = mb_detect_encoding($string, $try_encodings);
+      $guess = mb_detect_encoding($string, $try_encodings = null);
       if ($guess) {
         return mb_convert_encoding($string, 'UTF-8', $guess);
       }