Ignore trailing '/' when comparing pathnames, so that

"tar -u" works again.  Otherwise, "tar -u" wants to
treat every dir as new and re-adds it.

1 files changed, 26 insertions, 3 deletions

diff --git a/usr.bin/tar/util.c b/usr.bin/tar/util.c
index 9cc19d7..080252c 100644
--- a/usr.bin/tar/util.c
+++ b/usr.bin/tar/util.c
@@ -449,16 +449,39 @@ edit_pathname(struct bsdtar *bsdtar, struct archive_entry *entry)
 
 /*
  * Like strcmp(), but try to be a little more aware of the fact that
- * we're comparing two paths.
+ * we're comparing two paths.  Right now, it just handles leading
+ * "./" and trailing '/' specially, so that "a/b/" == "./a/b"
  *
- * TODO: Make this better, so that "./a//b/./c" == "a/b/c"
+ * TODO: Make this better, so that "./a//b/./c/" == "a/b/c"
+ * TODO: After this works, push it down into libarchive.
+ * TODO: Publish the path normalization routines in libarchive so
+ * that bsdtar can normalize paths and use fast strcmp() instead
+ * of this.
  */
+
 int
 pathcmp(const char *a, const char *b)
 {
+	/* Skip leading './' */
 	if (a[0] == '.' && a[1] == '/' && a[2] != '\0')
 		a += 2;
 	if (b[0] == '.' && b[1] == '/' && b[2] != '\0')
 		b += 2;
-	return (strcmp(a, b));
+	/* Find the first difference, or return (0) if none. */
+	while (*a == *b) {
+		if (*a == '\0')
+			return (0);
+		a++;
+		b++;
+	}
+	/*
+	 * If one ends in '/' and the other one doesn't,
+	 * they're the same.
+	 */
+	if (a[0] == '/' && a[1] == '\0' && b[0] == '\0')
+		return (0);
+	if (a[0] == '\0' && b[0] == '/' && b[1] == '\0')
+		return (0);
+	/* They're really different, return the correct sign. */
+	return (*(const unsigned char *)a - *(const unsigned char *)b);
 }