From b872ef866adfee1a5dbbfba7cc88fa1ce1f0482b Mon Sep 17 00:00:00 2001
From: Karen Etheridge <ether@cpan.org>
Date: Mon, 24 Feb 2025 14:30:40 -0800
Subject: [PATCH] fix_headers() now initializes Host header when needed
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

RFC9112 §3.2-5 says that Host is mandatory, but can be an empty value.
resolves issue #2232.
---
 lib/Mojo/Message/Request.pm | 2 +-
 t/mojo/request.t            | 5 +++++
 2 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/Mojo/Message/Request.pm b/lib/Mojo/Message/Request.pm
index c9bbd01395..1e1dd67ee7 100644
--- a/lib/Mojo/Message/Request.pm
+++ b/lib/Mojo/Message/Request.pm
@@ -73,7 +73,7 @@ sub fix_headers {
 
   # Host
   my $url = $self->url;
-  $headers->host($url->host_port) unless $headers->host;
+  $headers->host($url->host_port // '') unless defined $headers->host;
 
   # Basic authentication
   if ((my $info = $url->userinfo) && !$headers->authorization) {
diff --git a/t/mojo/request.t b/t/mojo/request.t
index e001d80feb..70b2b71114 100644
--- a/t/mojo/request.t
+++ b/t/mojo/request.t
@@ -475,6 +475,11 @@ subtest 'Parse full HTTP 1.0 request (no scheme and empty elements in path)' =>
   is $req->url,                     '//foo/bar//baz.html?foo=13', 'right URL';
   is $req->headers->content_type,   'text/plain',                 'right "Content-Type" value';
   is $req->headers->content_length, 27,                           'right "Content-Length" value';
+  is $req->headers->host,           undef,                        '"Host" value is not defined';
+
+  $req->fix_headers;
+  is $req->url->host,     undef, 'still no url host';
+  is $req->headers->host, '',    '"Host" value is fixed';
 };
 
 subtest 'Parse full HTTP 1.0 request (behind reverse proxy)' => sub {