attr.c::path_matches(): special case paths that end with a slash

The function is given a string that ends with a slash to signal that
the path is a directory to make sure that a pattern that ends with a
slash (i.e. MUSTBEDIR) can tell directories and non-directories
apart.  However, the pattern itself (pat->pattern and
pat->patternlen) that came from such a MUSTBEDIR pattern is
represented as a string that ends with a slash, but patternlen does
not count that trailing slash. A MUSTBEDIR pattern "element/" is
represented as a counted string <"element/", 7> and this must match
match pathname "element/".

Because match_basename() and match_pathname() want to see pathname
"element" to match against the pattern <"element/", 7>, reduce the
length of the path to exclude the trailing slash when calling
these functions.
Signed-off-by: NJunio C Hamano <gitster@pobox.com>
Signed-off-by: NJeff King <peff@peff.net>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

attr.c

@@ -661,18 +661,18 @@ static int path_matches(const char *pathname, int pathlen,
 {
 	const char *pattern = pat->pattern;
 	int prefix = pat->nowildcardlen;
+	int isdir = (pathlen && pathname[pathlen - 1] == '/');
 
-	if ((pat->flags & EXC_FLAG_MUSTBEDIR) &&
-	    ((!pathlen) || (pathname[pathlen-1] != '/')))
+	if ((pat->flags & EXC_FLAG_MUSTBEDIR) && !isdir)
 		return 0;
 
 	if (pat->flags & EXC_FLAG_NODIR) {
 		return match_basename(pathname + basename_offset,
-				      pathlen - basename_offset,
+				      pathlen - basename_offset - isdir,
 				      pattern, prefix,
 				      pat->patternlen, pat->flags);
 	}
-	return match_pathname(pathname, pathlen,
+	return match_pathname(pathname, pathlen - isdir,
 			      base, baselen,
 			      pattern, prefix, pat->patternlen, pat->flags);
 }