From f71b1a43a92c10b5d2313ccebac3d10cf8f911e5 Mon Sep 17 00:00:00 2001
From: Daniel Rocha <daniel@rocha.io>
Date: Sun, 17 Mar 2019 11:00:53 +0100
Subject: [PATCH] Change mod() function

---
 htp.go | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/htp.go b/htp.go
index a6cfb9a..f5a0c39 100644
--- a/htp.go
+++ b/htp.go
@@ -112,7 +112,11 @@ func max(a, b int64) int64 {
 }
 
 func mod(x, m int64) int64 {
-	return (m + x%m) % m
+	y := x % m
+	if y >= 0 {
+		return y
+	}
+	return m + y
 }
 
 func noRedirect(req *http.Request, via []*http.Request) error {