Bug 1152319: calling /rest/logout results in an internal error and a malformed…

Bugzilla/WebService/Server/REST.pm

@@ -130,6 +130,16 @@ sub response {
         $result = $json_data->{result};
     }
 
+    # The result needs to be a valid JSON data structure
+    # and not a undefined or scalar value.
+    if (!ref $result
+        || blessed($result)
+        || ref $result ne 'HASH'
+        || ref $result ne 'ARRAY')
+    {
+        $result = { result => $result };
+    }
+
     Bugzilla::Hook::process('webservice_rest_response',
         { rpc => $self, result => \$result, response => $response });