From 7658fd20d711001705cde6e1725eed545e58a2ea Mon Sep 17 00:00:00 2001
From: Bruce Evans <bde@FreeBSD.org>
Date: Fri, 30 Dec 1994 13:12:12 +0000
Subject: [PATCH] Don't strip off the last slash in the pathname "/".  cp used
 to stat the pathname "" in order to decide that the pathname "/" is a
 directory.  This caused `cp kernel /' to fail if the kernel has the POSIX
 behaviour of not allowing the pathname "" to be an alias for ".".  It
 presumably also caused `cp /etc/motd /' to fail in the unlikely event that
 "." is not stat'able.

Be more careful about concatenating pathnames: don't check that
the pathname fits until prefixes have been discarded (the check
was too strict).  Print the final pathname in error messages.
Terminate the target directory name properly for error messages.
Don't add a slash between components if there is already a slash.
---
 bin/cp/cp.c | 33 +++++++++++++++------------------
 1 file changed, 15 insertions(+), 18 deletions(-)

diff --git a/bin/cp/cp.c b/bin/cp/cp.c
index 5a81a9803da3..d8a2c8dcd424 100644
--- a/bin/cp/cp.c
+++ b/bin/cp/cp.c
@@ -33,7 +33,7 @@
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
  *
- *	$Id$
+ *	$Id: cp.c,v 1.2 1994/09/24 02:53:41 davidg Exp $
  */
 
 #ifndef lint
@@ -79,7 +79,7 @@ static char sccsid[] = "@(#)cp.c	8.2 (Berkeley) 4/1/94";
 #include "extern.h"
 
 #define	STRIP_TRAILING_SLASH(p) {					\
-        while ((p).p_end > (p).p_path && (p).p_end[-1] == '/')		\
+        while ((p).p_end > (p).p_path + 1 && (p).p_end[-1] == '/')	\
                 *--(p).p_end = 0;					\
 }
 
@@ -253,7 +253,7 @@ copy(argv, type, fts_options)
 	FTS *ftsp;
 	FTSENT *curr;
 	int base, dne, nlen, rval;
-	char *p;
+	char *p, *target_mid;
 
 	if ((ftsp = fts_open(argv, fts_options, mastercmp)) == NULL)
 		err(1, NULL);
@@ -278,14 +278,6 @@ copy(argv, type, fts_options)
                  * source name to the target name.  
                  */
 		if (type != FILE_TO_FILE) {
-			if ((curr->fts_namelen +
-			    to.target_end - to.p_path + 1) > MAXPATHLEN) {
-				warnx("%s/%s: name too long (not copied)", 
-				    to.p_path, curr->fts_name);
-				rval = 1;
-				continue;
-			}
-
 			/*
 			 * Need to remember the roots of traversals to create
 			 * correct pathnames.  If there's a directory being
@@ -317,15 +309,20 @@ copy(argv, type, fts_options)
 				} else
 					base = curr->fts_pathlen;
 
-			if (to.target_end[-1] != '/') {
-				*to.target_end = '/';
-				*(to.target_end + 1) = 0;
-			}
 			p = &curr->fts_path[base];
 			nlen = curr->fts_pathlen - base;
-
-			(void)strncat(to.target_end + 1, p, nlen);
-			to.p_end = to.target_end + nlen + 1;
+			target_mid = to.target_end;
+			if (*p != '/' && target_mid[-1] != '/')
+				*target_mid++ = '/';
+			*target_mid = 0;
+			if (target_mid - to.p_path + nlen > MAXPATHLEN) {
+				warnx("%s%s: name too long (not copied)", 
+				    to.p_path, p);
+				rval = 1;
+				continue;
+			}
+			(void)strncat(target_mid, p, nlen);
+			to.p_end = target_mid + nlen;
 			*to.p_end = 0;
 			STRIP_TRAILING_SLASH(to);
 		}