From 18d51bdeb5da7a87ec8ade4aa8d97528cce57db9 Mon Sep 17 00:00:00 2001
From: Jim Meyering <jim@meyering.net>
Date: Fri, 4 Oct 1996 13:42:20 +0000
Subject: [PATCH] Add assertions.

---
 lib/memcpy.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/lib/memcpy.c b/lib/memcpy.c
index dba7d56f1..aec71e36b 100644
--- a/lib/memcpy.c
+++ b/lib/memcpy.c
@@ -2,6 +2,15 @@
    if the source overlaps with the destination.
    Return DESTADDR. */
 
+#include <assert.h>
+
+/* FIXME: uncomment the following for releases.  */
+#define NDEBUG 1
+
+#ifndef ABS
+# define ABS(x) ((x) < 0 ? (-(x)) : (x))
+#endif
+
 char *
 memcpy (destaddr, srcaddr, len)
      char *destaddr;
@@ -10,6 +19,10 @@ memcpy (destaddr, srcaddr, len)
 {
   char *dest = destaddr;
 
+  assert (len >= 0);
+  /* Make sure they don't overlap.  */
+  assert (ABS (destaddr - srcaddr) >= len);
+
   while (len-- > 0)
     *destaddr++ = *srcaddr++;
   return dest;
-- 
2.11.0