--- Libc/Libc-1725.40.4/secure/strcat_chk.c
+++ Libc/Libc-583/secure/strcat_chk.c
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2007-2013 Apple Inc. All rights reserved.
+ * Copyright (c) 2007 Apple Inc. All rights reserved.
  *
  * @APPLE_LICENSE_HEADER_START@
  *
@@ -24,21 +24,28 @@
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
-#include "secure.h"
+
+extern void __chk_fail (void) __attribute__((__noreturn__));
 
 char *
-__strcat_chk (char *__restrict dest, const char *__restrict append,
-	      size_t dstlen)
+__strcat_chk (char *__restrict s, const char *__restrict append,
+	      size_t slen)
 {
-  size_t len1 = strlen(dest);
-  size_t len2 = strlen(append);
+  char *save = s;
 
-  if (__builtin_expect (dstlen < len1 + len2 + 1, 0))
-    __chk_fail_overflow ();
+  /* Advance to the end. */
+  for (; *s; ++s)
+    if (__builtin_expect (slen-- == 0, 0))
+      __chk_fail ();
 
-  if (__builtin_expect (__chk_assert_no_overlap != 0, 1))
-    __chk_overlap(dest, len1 + len2 + 1, append, len2 + 1);
+  do
+    {
+      /* Append the string.  Make sure we check before writing.  */
+      if (__builtin_expect (slen-- == 0, 0))
+	__chk_fail ();
 
-  memcpy(dest + len1, append, len2 + 1);
-  return dest;
+    } while (*s++ = *append++);
+
+  return save;
+
 }