[ruby/rubygems] Fix Gem::Request proxy env lookup when required directly

ruby/rubygems@db8fd6becb

Author: afurm

lib/rubygems/request.rb

@@ -2,6 +2,7 @@
 
 require_relative "vendored_net_http"
 require_relative "user_interaction"
+require_relative "uri_formatter"
 
 class Gem::Request
   extend Gem::UserInteraction

test/rubygems/test_gem_request.rb

@@ -2,6 +2,7 @@
 
 require_relative "helper"
 require "rubygems/request"
+require "open3"
 
 unless Gem::HAVE_OPENSSL
   warn "Skipping Gem::Request tests.  openssl not found."
@@ -189,6 +190,18 @@ def test_get_proxy_from_env_empty
     assert_nil request.proxy_uri
   end
 
+  def test_get_proxy_from_env_when_requiring_request_directly
+    script = <<~RUBY
+      require "rubygems/request"
+      ENV["HTTP_PROXY"] = "fakeurl:12345"
+      Gem::Request.get_proxy_from_env("http")
+    RUBY
+
+    output, status = Open3.capture2e(*ruby_with_rubygems_in_load_path, "-e", script)
+
+    assert status.success?, output
+  end
+
   def test_fetch
     uri = Gem::Uri.new(Gem::URI.parse("#{@gem_repo}/specs.#{Gem.marshal_version}"))
     response = util_stub_net_http(body: :junk, code: 200) do