From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sun, 30 Jun 2024 10:31:55 +0000 (+0100)
Subject: Update from gnulib
X-Git-Url: http://git.eshelyaron.com/gitweb/?a=commitdiff_plain;h=9e4e4ba3015c6e187be17ac700ca91c0eb7da19d;p=emacs.git

Update from gnulib

(cherry picked from commit 7f89fe8a342d7b4e8800d0ef333fb6759b58ccb5)
---

diff --git a/lib/strnlen.c b/lib/strnlen.c
index 80857ec22b0..5231e4c595d 100644
--- a/lib/strnlen.c
+++ b/lib/strnlen.c
@@ -1,6 +1,5 @@
 /* Find the length of STRING, but scan at most MAXLEN characters.
    Copyright (C) 2005-2007, 2009-2024 Free Software Foundation, Inc.
-   Written by Simon Josefsson.
 
    This file is free software: you can redistribute it and/or modify
    it under the terms of the GNU Lesser General Public License as
@@ -19,12 +18,17 @@
 
 #include <string.h>
 
-/* Find the length of STRING, but scan at most MAXLEN characters.
-   If no '\0' terminator is found in that many characters, return MAXLEN.  */
+/* Find the length of S, but scan at most MAXLEN bytes.
+   S must be a string if it starts with fewer than MAXLEN initialized bytes.
+   If no '\0' terminator is found in that many bytes, return MAXLEN.  */
 
 size_t
-strnlen (const char *string, size_t maxlen)
+strnlen (const char *s, size_t maxlen)
 {
-  const char *end = memchr (string, '\0', maxlen);
-  return end ? (size_t) (end - string) : maxlen;
+  /* Do not use memchr, because on some platforms memchr has
+     undefined behavior if MAXLEN exceeds the number of bytes in S.  */
+  size_t i;
+  for (i = 0; i < maxlen && s[i]; i++)
+    continue;
+  return i;
 }