From a954d2fda18a17061b765e628d209f66173e3268 Mon Sep 17 00:00:00 2001
From: Tim Kientzle <kientzle@gmail.com>
Date: Sat, 3 Oct 2009 17:44:41 -0400
Subject: [PATCH] Only accept \ as path separator when reading archives on
 Windows.  This seems to offer the best trade-off of compatibility and
 correctness.

SVN-Revision: 1480
---
 tar/tree.c |  9 +++------
 tar/util.c | 34 ++++++++++++++++++++++++----------
 2 files changed, 27 insertions(+), 16 deletions(-)

diff --git a/tar/tree.c b/tar/tree.c
index 5fbd3c720..eeae00b03 100644
--- a/tar/tree.c
+++ b/tar/tree.c
@@ -72,9 +72,6 @@ __FBSDID("$FreeBSD: src/usr.bin/tar/tree.c,v 1.9 2008/11/27 05:49:52 kientzle Ex
 #endif
 #if defined(HAVE_WINDOWS_H) && !defined(__CYGWIN__)
 #include <windows.h>
-#define DIRSEP '\\'
-#else
-#define DIRSEP '/'
 #endif
 
 #include "tree.h"
@@ -255,8 +252,8 @@ tree_append(struct tree *t, const char *name, size_t name_length)
 	p = t->buff + t->dirname_length;
 	t->path_length = t->dirname_length + name_length;
 	/* Add a separating '/' if it's needed. */
-	if (t->dirname_length > 0 && p[-1] != '/' && p[-1] != '\\') {
-		*p++ = DIRSEP;
+	if (t->dirname_length > 0 && p[-1] != '/') {
+		*p++ = '/';
 		t->path_length ++;
 	}
 #if HAVE_STRNCPY_S
@@ -349,7 +346,7 @@ tree_pop(struct tree *t)
 	t->dirname_length = te->dirname_length;
 	if (t->buff) {
 		t->basename = t->buff + t->dirname_length;
-		while (t->basename[0] == '/' || t->basename[0] == '\\')
+		while (t->basename[0] == '/')
 			t->basename++;
 	}
 	free(te->name);
diff --git a/tar/util.c b/tar/util.c
index d2a3126d8..2ae448e61 100644
--- a/tar/util.c
+++ b/tar/util.c
@@ -298,15 +298,16 @@ do_chdir(struct bsdtar *bsdtar)
 }
 
 const char *
-strip_components(const char *path, int elements)
+strip_components(const char *p, int elements)
 {
-	const char *p = path;
-
+	/* Skip as many elements as necessary. */
 	while (elements > 0) {
 		switch (*p++) {
 		case '/':
+#if defined(_WIN32) && !defined(__CYGWIN__)
+		case '\\': /* Support \ path sep on Windows ONLY. */
+#endif
 			elements--;
-			path = p;
 			break;
 		case '\0':
 			/* Path is too short, skip it. */
@@ -314,12 +315,25 @@ strip_components(const char *path, int elements)
 		}
 	}
 
-	while (*path == '/')
-	       ++path;
-	if (*path == '\0')
-	       return (NULL);
-
-	return (path);
+	/* Skip any / characters.  This handles short paths that have
+	 * additional / termination.  This also handles the case where
+	 * the logic above stops in the middle of a duplicate //
+	 * sequence (which would otherwise get converted to an
+	 * absolute path). */
+	for (;;) {
+		switch (*p) {
+		case '/':
+#if defined(_WIN32) && !defined(__CYGWIN__)
+		case '\\': /* Support \ path sep on Windows ONLY. */
+#endif
+			++p;
+			break;
+		case '\0':
+			return (NULL);
+		default:
+			return (p);
+		}
+	}
 }
 
 /*
-- 
2.47.3