Merge #7473

7473: Cleanup some unnecessary code r=deivid-rodriguez a=deivid-rodriguez

### What was the end-user problem that led to this PR?

The problem was #7460 is very big so I want to extract these changes to a separate PR, so that we're more aware of them.

### What was your diagnosis of the problem?

My diagnosis was that this code can be removed. In particular, in the `GemRemoteFetcher` class there was the following comment

https://github.com/bundler/bundler/blob/25595896eb0f8dfd004d941093bf1d8f4a39aeeb/lib/bundler/gem_remote_fetcher.rb#L9-L10

After having a look, I think the comment would make sense if where it says "gemstash", it actually meant "bundler". That would make sense to me since this is about fetching remote specs, so I would assume it's the client side running it.

Assuming this is the correct interpretation, we can remove the code since our minimum supported rubygems version is 2.5.2, and this code was included in rubygems in 2.5.0.

### What is your fix for the problem, implemented in this PR?

My fix is to remove the `GemRemoteFetcher` class, plus simplify other related code.

Co-authored-by: David Rodríguez <deivid.rodriguez@riseup.net>
(cherry picked from commit bada03dd6d4d15828fb5b2cf7f744948e88a69a3)

4 files changed, 6 insertions, 58 deletions

diff --git a/lib/bundler.rb b/lib/bundler.rb
index 3b494a6cdf..df345539c8 100644
--- a/lib/bundler.rb
+++ b/lib/bundler.rb
@@ -50,7 +50,6 @@ module Bundler
   autoload :FeatureFlag,            File.expand_path("bundler/feature_flag", __dir__)
   autoload :GemHelper,              File.expand_path("bundler/gem_helper", __dir__)
   autoload :GemHelpers,             File.expand_path("bundler/gem_helpers", __dir__)
-  autoload :GemRemoteFetcher,       File.expand_path("bundler/gem_remote_fetcher", __dir__)
   autoload :GemVersionPromoter,     File.expand_path("bundler/gem_version_promoter", __dir__)
   autoload :Graph,                  File.expand_path("bundler/graph", __dir__)
   autoload :Index,                  File.expand_path("bundler/index", __dir__)
diff --git a/lib/bundler/gem_remote_fetcher.rb b/lib/bundler/gem_remote_fetcher.rb
deleted file mode 100644
index 9577535d63..0000000000
--- a/lib/bundler/gem_remote_fetcher.rb
+++ /dev/null
@@ -1,43 +0,0 @@
-# frozen_string_literal: true
-
-require "rubygems/remote_fetcher"
-
-module Bundler
-  # Adds support for setting custom HTTP headers when fetching gems from the
-  # server.
-  #
-  # TODO: Get rid of this when and if gemstash only supports RubyGems versions
-  # that contain https://github.com/rubygems/rubygems/commit/3db265cc20b2f813.
-  class GemRemoteFetcher < Gem::RemoteFetcher
-    attr_accessor :headers
-
-    # Extracted from RubyGems 2.4.
-    def fetch_http(uri, last_modified = nil, head = false, depth = 0)
-      fetch_type = head ? Net::HTTP::Head : Net::HTTP::Get
-      # beginning of change
-      response   = request uri, fetch_type, last_modified do |req|
-        headers.each {|k, v| req.add_field(k, v) } if headers
-      end
-      # end of change
-
-      case response
-      when Net::HTTPOK, Net::HTTPNotModified then
-        response.uri = uri if response.respond_to? :uri
-        head ? response : response.body
-      when Net::HTTPMovedPermanently, Net::HTTPFound, Net::HTTPSeeOther,
-           Net::HTTPTemporaryRedirect then
-        raise FetchError.new("too many redirects", uri) if depth > 10
-
-        location = URI.parse response["Location"]
-
-        if https?(uri) && !https?(location)
-          raise FetchError.new("redirecting to non-https resource: #{location}", uri)
-        end
-
-        fetch_http(location, last_modified, head, depth + 1)
-      else
-        raise FetchError.new("bad response #{response.message} #{response.code}", uri)
-      end
-    end
-  end
-end
diff --git a/lib/bundler/rubygems_integration.rb b/lib/bundler/rubygems_integration.rb
index c4950d14e8..bb63209632 100644
--- a/lib/bundler/rubygems_integration.rb
+++ b/lib/bundler/rubygems_integration.rb
@@ -247,12 +247,6 @@ module Bundler
       EXT_LOCK
     end
 
-    def fetch_prerelease_specs
-      fetch_specs(false, true)
-    rescue Gem::RemoteFetcher::FetchError
-      {} # if we can't download them, there aren't any
-    end
-
     def with_build_args(args)
       ext_lock.synchronize do
         old_args = build_args
@@ -531,8 +525,8 @@ module Bundler
       end
     end
 
-    def fetch_specs(source, remote, name)
-      path = source + "#{name}.#{Gem.marshal_version}.gz"
+    def fetch_specs(remote, name)
+      path = remote.uri.to_s + "#{name}.#{Gem.marshal_version}.gz"
       fetcher = gem_remote_fetcher
       fetcher.headers = { "X-Gemfile-Source" => remote.original_uri.to_s } if remote.original_uri
       string = fetcher.fetch_path(path)
@@ -543,10 +537,8 @@ module Bundler
     end
 
     def fetch_all_remote_specs(remote)
-      source = remote.uri.is_a?(URI) ? remote.uri : URI.parse(source.to_s)
-
-      specs = fetch_specs(source, remote, "specs")
-      pres = fetch_specs(source, remote, "prerelease_specs") || []
+      specs = fetch_specs(remote, "specs")
+      pres = fetch_specs(remote, "prerelease_specs") || []
 
       specs.concat(pres)
     end
@@ -564,7 +556,7 @@ module Bundler
       require "resolv"
       proxy = configuration[:http_proxy]
       dns = Resolv::DNS.new
-      Bundler::GemRemoteFetcher.new(proxy, dns)
+      Gem::RemoteFetcher.new(proxy, dns)
     end
 
     def gem_from_path(path, policy = nil)
diff --git a/spec/bundler/rubygems_integration_spec.rb b/spec/bundler/rubygems_integration_spec.rb
index 26cbaa630b..ce2b100088 100644
--- a/spec/bundler/rubygems_integration_spec.rb
+++ b/spec/bundler/rubygems_integration_spec.rb
@@ -67,7 +67,7 @@ RSpec.describe Bundler::RubygemsIntegration do
   end
 
   describe "#fetch_all_remote_specs" do
-    let(:uri) { URI("https://example.com") }
+    let(:uri) { "https://example.com" }
     let(:fetcher) { double("gem_remote_fetcher") }
     let(:specs_response) { Marshal.dump(["specs"]) }
     let(:prerelease_specs_response) { Marshal.dump(["prerelease_specs"]) }