Rack::Request#host returns unexpected host when the domain starts with a number

[pocke]

Problem

Rack::Request#host returns unexpected host when the domain starts with a number.

Rack v2.1.2 returns host correctly.

gem 'rack', '2.1.2'
require 'rack'

p Rack::Request.new({'HTTP_HOST' => '123foo.example.com'}).host
# => "123foo.example.com"

But Rack v2.2.0 (and v2.2.1) returns a part of the host unexpectedly.

gem 'rack', '2.2.0'
require 'rack'


p Rack::Request.new({'HTTP_HOST' => '123foo.example.com'}).host
# => "123"

I guess the cause is the following pull request. #1561

rack/lib/rack/request.rb

Lines 601 to 615 in 838ce3a

	AUTHORITY = /
	# The host:
	(?<host>
	# An IPv6 address:
	(\[(?<ip6>.*)\])
	|
	# An IPv4 address:
	(?<ip4>[\d\.]+)
	|
	# A hostname:
	(?<name>[a-zA-Z0-9\.\-]+)
	)
	# The optional port:
	(:(?<port>\d+))?
	/x

The AUTHORITY regexp looks too loose. 123 matches as an ip4, but it is not an ip4.

[ioquatix]

Yes, that's correct, I guess we need to force it to match the full string. Thanks for the report.

[ioquatix]

I thought it would be greedy by default but it wasn't.

Changing AUTHORITY to:

AUTHORITY = /^
	# The host:
	(?<host>
		# An IPv6 address:
		(\[(?<ip6>.*)\])
		|
		# An IPv4 address:
		(?<ip4>[\d\.]+)
		|
		# A hostname:
		(?<name>[a-zA-Z0-9\.\-]+)
	)
	# The optional port:
	(:(?<port>\d+))?
$/x

fixes the issue for me.

[pocke]

Thank you for quick fixing!

[ioquatix]

Released now in v2.2.2 - thanks for reporting the issue with an easy repro!