According to POSIX, if the src and dst strings overlap, the behavior

is undefined.  Add a warning to that effect.  OK deraadt@ jmc@

1 files changed, 8 insertions, 2 deletions

diff --git a/src/lib/libc/string/strcpy.3 b/src/lib/libc/string/strcpy.3
index 409f4c61d4..798c7e8d99 100644
--- a/src/lib/libc/string/strcpy.3
+++ b/src/lib/libc/string/strcpy.3
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: strcpy.3,v 1.18 2013/07/17 05:42:11 schwarze Exp $
+.\"     $OpenBSD: strcpy.3,v 1.19 2013/09/25 21:49:31 millert Exp $
 .\"
 .\" Copyright (c) 1990, 1991 The Regents of the University of California.
 .\" All rights reserved.
@@ -31,7 +31,7 @@
 .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 .\" SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: July 17 2013 $
+.Dd $Mdocdate: September 25 2013 $
 .Dt STRCPY 3
 .Os
 .Sh NAME
@@ -77,6 +77,12 @@ if the length of
 .Fa src
 is greater than or equal to
 .Fa len .
+.Pp
+If the
+.Fa src
+and
+.Fa dst
+strings overlap, the behavior is undefined.
 .Sh RETURN VALUES
 The
 .Fn strcpy