From 6b7a2c4cf74fe8d73a6c247ba6b078f9a70e6ff2 Mon Sep 17 00:00:00 2001
From: Tsuda Kageyu <tsuda.kageyu@gmail.com>
Date: Tue, 17 Nov 2015 11:41:13 +0900
Subject: [PATCH] Add some notes about String::isNull() and String::null.

---
 taglib/toolkit/tstring.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/taglib/toolkit/tstring.h b/taglib/toolkit/tstring.h
index 68592f40..a2ee19ff 100644
--- a/taglib/toolkit/tstring.h
+++ b/taglib/toolkit/tstring.h
@@ -332,7 +332,9 @@ namespace TagLib {
      * Returns true if this string is null -- i.e. it is a copy of the
      * String::null string.
      *
-     * \note A string can be empty and not null.
+     * \note A string can be empty and not null.  So do not use this method to
+     * check if the string is empty.
+     *
      * \see isEmpty()
      */
     bool isNull() const;
@@ -508,6 +510,9 @@ namespace TagLib {
 
     /*!
      * A null string provided for convenience.
+     *
+     * \warning Do not modify this variable.  It will mess up the internal state
+     * of TagLib.
      */
     static String null;
 
-- 
2.40.0