From 81725b867c20a688c3877421383bfe1ba9348a09 Mon Sep 17 00:00:00 2001
From: Lukas Tribus <lukas@ltri.eu>
Date: Thu, 27 Feb 2020 15:47:24 +0100
Subject: [PATCH] BUG/MINOR: dns: ignore trailing dot

As per issue #435 a hostname with a trailing dot confuses our DNS code,
as for a zero length DNS label we emit a null-byte. This change makes us
ignore the zero length label instead.

Must be backported to 1.8.
---
 src/dns.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/dns.c b/src/dns.c
index 86147a417..bbc4f4ac1 100644
--- a/src/dns.c
+++ b/src/dns.c
@@ -1450,6 +1450,12 @@ int dns_str_to_dn_label(const char *str, int str_len, char *dn, int dn_len)
 			if (i == offset)
 				return -1;
 
+			/* ignore trailing dot */
+			if (i + 2 == str_len) {
+				i++;
+				break;
+			}
+
 			dn[offset] = (i - offset);
 			offset = i+1;
 			continue;