buildroot/package/systemd/0003-network-generator-allow-empty-hostname.patch

From 21a925a4ac7955e7d7e6cfd477e96d3a2aaee7db Mon Sep 17 00:00:00 2001
From: Yu Watanabe <watanabe.yu+github@gmail.com>
Date: Thu, 12 Dec 2019 19:01:21 +0900
Subject: [PATCH 1/1] network-generator: allow empty hostname

Fixes #14319.

[Brandon: backport from https://github.com/systemd/systemd/commit/21a925a4ac7955e7d7e6cfd477e96d3a2aaee7db]
Signed-off-by: Brandon Maier <brandon.maier@rockwellcollins.com>
---
 src/network/generator/network-generator.c | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/network/generator/network-generator.c b/src/network/generator/network-generator.c
index 81afa95307..bed1e42697 100644
--- a/src/network/generator/network-generator.c
+++ b/src/network/generator/network-generator.c
@@ -574,7 +574,7 @@ static int parse_netmask_or_prefixlen(int family, const char **value, unsigned c
 
 static int parse_cmdline_ip_address(Context *context, int family, const char *value) {
         union in_addr_union addr = {}, peer = {}, gateway = {};
-        const char *hostname, *ifname, *dhcp_type, *dns, *p;
+        const char *hostname = NULL, *ifname, *dhcp_type, *dns, *p;
         unsigned char prefixlen;
         int r;
 
@@ -599,9 +599,11 @@ static int parse_cmdline_ip_address(Context *context, int family, const char *va
         if (!p)
                 return -EINVAL;
 
-        hostname = strndupa(value, p - value);
-        if (!hostname_is_valid(hostname, false))
-                return -EINVAL;
+        if (p != value) {
+                hostname = strndupa(value, p - value);
+                if (!hostname_is_valid(hostname, false))
+                        return -EINVAL;
+        }
 
         value = p + 1;
 
-- 
2.23.0