From: Antonio Terceiro <terceiro@debian.org>
Date: Sat, 27 Feb 2021 09:25:18 -0300
Subject: Make tests pass on hosts that have no ipv4 connectivity

This is a backport of the patch sent upstream.

Forwarded: https://github.com/rack/rack/pull/1738
---
 test/spec_server.rb  | 8 ++++----
 test/spec_thin.rb    | 4 ++--
 test/spec_webrick.rb | 6 +++---
 3 files changed, 9 insertions(+), 9 deletions(-)

diff --git a/test/spec_server.rb b/test/spec_server.rb
index 8aecc55..d55b5a8 100644
--- a/test/spec_server.rb
+++ b/test/spec_server.rb
@@ -123,8 +123,8 @@ describe Rack::Server do
       app: app,
       environment: 'none',
       pid: pidfile.path,
-      Port: TCPServer.open('127.0.0.1', 0){|s| s.addr[1] },
-      Host: '127.0.0.1',
+      Port: TCPServer.open('localhost', 0){|s| s.addr[1] },
+      Host: 'localhost',
       Logger: WEBrick::Log.new(nil, WEBrick::BasicLog::WARN),
       AccessLog: [],
       daemonize: false,
@@ -133,9 +133,9 @@ describe Rack::Server do
     t = Thread.new { server.start { |s| Thread.current[:server] = s } }
     t.join(0.01) until t[:server] && t[:server].status != :Stop
     body = if URI.respond_to?(:open)
-             URI.open("http://127.0.0.1:#{server.options[:Port]}/") { |f| f.read }
+             URI.open("http://localhost:#{server.options[:Port]}/") { |f| f.read }
            else
-             open("http://127.0.0.1:#{server.options[:Port]}/") { |f| f.read }
+             open("http://localhost:#{server.options[:Port]}/") { |f| f.read }
            end
     body.must_equal 'success'
 
diff --git a/test/spec_thin.rb b/test/spec_thin.rb
index 0729c3f..37a5f32 100644
--- a/test/spec_thin.rb
+++ b/test/spec_thin.rb
@@ -15,7 +15,7 @@ describe Rack::Handler::Thin do
     Thin::Logging.silent = true
 
     @thread = Thread.new do
-      Rack::Handler::Thin.run(@app, Host: @host = '127.0.0.1', Port: @port = 9204, tag: "tag") do |server|
+      Rack::Handler::Thin.run(@app, Host: @host = 'localhost', Port: @port = 9204, tag: "tag") do |server|
         @server = server
       end
     end
@@ -41,7 +41,7 @@ describe Rack::Handler::Thin do
     response["HTTP_VERSION"].must_equal "HTTP/1.1"
     response["SERVER_PROTOCOL"].must_equal "HTTP/1.1"
     response["SERVER_PORT"].must_equal "9204"
-    response["SERVER_NAME"].must_equal "127.0.0.1"
+    response["SERVER_NAME"].must_equal "localhost"
   end
 
   it "have rack headers" do
diff --git a/test/spec_webrick.rb b/test/spec_webrick.rb
index 0d0aa8f..3f04a49 100644
--- a/test/spec_webrick.rb
+++ b/test/spec_webrick.rb
@@ -11,7 +11,7 @@ describe Rack::Handler::WEBrick do
   include TestRequest::Helpers
 
   before do
-  @server = WEBrick::HTTPServer.new(Host: @host = '127.0.0.1',
+  @server = WEBrick::HTTPServer.new(Host: @host = 'localhost',
                                     Port: @port = 9202,
                                     Logger: WEBrick::Log.new(nil, WEBrick::BasicLog::WARN),
                                     AccessLog: [])
@@ -46,7 +46,7 @@ describe Rack::Handler::WEBrick do
     response["HTTP_VERSION"].must_equal "HTTP/1.1"
     response["SERVER_PROTOCOL"].must_equal "HTTP/1.1"
     response["SERVER_PORT"].must_equal "9202"
-    response["SERVER_NAME"].must_equal "127.0.0.1"
+    response["SERVER_NAME"].must_equal "localhost"
   end
 
   it "have rack headers" do
@@ -126,7 +126,7 @@ describe Rack::Handler::WEBrick do
     t = Thread.new do
       Rack::Handler::WEBrick.run(lambda {},
                                  {
-                                   Host: '127.0.0.1',
+                                   Host: 'localhost',
                                    Port: 9210,
                                    Logger: WEBrick::Log.new(nil, WEBrick::BasicLog::WARN),
                                    AccessLog: [] }) { |server|