git-send-email: Do not make @-less message ID

diff --git a/diffcore.h b/diffcore.h
index 1ea80671e30500f95fc1b648ccc6d5143ac0ac52..7b9294eab2c1cb9f7cb03307c90203344d97e3f6 100644 (file)
--- a/diffcore.h
+++ b/diffcore.h
@@ -1,8 +1,8 @@
 /*
  * Copyright (C) 2005 Junio C Hamano
  */
-#ifndef _DIFFCORE_H_
-#define _DIFFCORE_H_
+#ifndef DIFFCORE_H
+#define DIFFCORE_H
 
 /* This header file is internal between diff.c and its diff transformers
  * (e.g. diffcore-rename, diffcore-pickaxe).  Never include this header