From 403b047a3043000953241ffd5fc67437e9ba117e Mon Sep 17 00:00:00 2001
From: Jakob Kramer <jakob.kramer@gmx.de>
Date: Sun, 5 Apr 2015 21:36:04 +0200
Subject: [PATCH] sort: allow keys where start_col > end_col

Useful in (rare) cases like:

	$ printf 'aaaa c\nx a\n0 b\n' | sort -k 2,1.3

And this is how POSIX wants it.
---
 sort.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/sort.c b/sort.c
index 3697b42..901189e 100644
--- a/sort.c
+++ b/sort.c
@@ -157,7 +157,7 @@ parse_keydef(struct keydef *kd, char *s, int flags)
 		return -1;
 	if (*rest == ',') {
 		kd->end_column = strtol(rest+1, &rest, 10);
-		if (kd->end_column && kd->end_column < kd->start_column)
+		if (kd->end_column < 1)
 			return -1;
 		if (*rest == '.') {
 			kd->end_char = strtol(rest+1, &rest, 10);