line-range: fix "blame -L X,-N" regression

sunshineco · gitster · commit 3bf65f9e62d2 · 2013-07-17T18:02:12.000-07:00
"blame -L X,-N" is documented as blaming "N lines ending at X". In practice, the behavior is achieved by swapping the two range endpoints if the second is less than the first. 25ed341 (Refactor parse_loc; 2013-03-28) broke this interpretation by removing the swapping code from blame.c and failing to add it to line-range.c along with other code relocated from blame.c. Thus, such a range is effectively treated as empty. Fix this regression. Signed-off-by: Eric Sunshine <sunshine@sunshineco.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/line-range.c b/line-range.c
@@ -211,6 +211,8 @@ int parse_range_arg(const char *arg, nth_line_fn_t nth_line_cb,
 		    void *cb_data, long lines, long *begin, long *end,
 		    const char *path)
 {
+	*begin = *end = 0;
+
 	if (*arg == ':') {
 		arg = parse_range_funcname(arg, nth_line_cb, cb_data, lines, begin, end, path);
 		if (!arg || *arg)
@@ -226,6 +228,11 @@ int parse_range_arg(const char *arg, nth_line_fn_t nth_line_cb,
 	if (*arg)
 		return -1;
 
+	if (*begin && *end && *end < *begin) {
+		long tmp;
+		tmp = *end; *end = *begin; *begin = tmp;
+	}
+
 	return 0;
 }
 
