absolute_path(): reject the empty string

Signed-off-by: NMichael Haggerty <mhagger@alum.mit.edu>
Signed-off-by: NJunio C Hamano <gitster@pobox.com>

abspath.c

@@ -123,7 +123,9 @@ const char *absolute_path(const char *path)
 {
 	static char buf[PATH_MAX + 1];
 
-	if (is_absolute_path(path)) {
+	if (!*path) {
+		die("The empty string is not a valid path");
+	} else if (is_absolute_path(path)) {
 		if (strlcpy(buf, path, PATH_MAX) >= PATH_MAX)
 			die("Too long path: %.*s", 60, path);
 	} else {

t/t0060-path-utils.sh

@@ -140,7 +140,7 @@ test_expect_success 'strip_path_suffix' '
 		c:/msysgit/libexec//git-core libexec/git-core)
 '
 
-test_expect_failure 'absolute path rejects the empty string' '
+test_expect_success 'absolute path rejects the empty string' '
 	test_must_fail test-path-utils absolute_path ""
 '