Merge #7043

7043: Remove old rubygems compatibility code r=bronzdoc a=deivid-rodriguez

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

The problem was that I was unsure where I needed to add the compatibility layer to #6963, and it took me a bit to scan through the compatibility file and figure it out.

### What was your diagnosis of the problem?

My diagnosis was that all this compatibility code is unused but makes this file harder to understand and scan through.

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

My fix is to remove the code.

### Why did you choose this fix out of the possible options?

I chose this fix because we can do it, I think.

Co-authored-by: David Rodríguez <deivid.rodriguez@riseup.net>

2 files changed, 117 insertions, 349 deletions

diff --git a/lib/bundler/rubygems_ext.rb b/lib/bundler/rubygems_ext.rb
index ccf71c8c00..beed6372a3 100644
--- a/lib/bundler/rubygems_ext.rb
+++ b/lib/bundler/rubygems_ext.rb
@@ -4,40 +4,25 @@ require "pathname"
 
 require "rubygems/specification"
 
-begin
-  # Possible use in Gem::Specification#source below and require
-  # shouldn't be deferred.
-  require "rubygems/source"
-rescue LoadError
-  # Not available before RubyGems 2.0.0, ignore
-  nil
-end
+# Possible use in Gem::Specification#source below and require
+# shouldn't be deferred.
+require "rubygems/source"
 
 require "bundler/match_platform"
 
 module Gem
-  @loaded_stacks = Hash.new {|h, k| h[k] = [] }
-
   class Specification
     attr_accessor :remote, :location, :relative_loaded_from
 
-    if instance_methods(false).include?(:source)
-      remove_method :source
-      attr_writer :source
-      def source
-        (defined?(@source) && @source) || Gem::Source::Installed.new
-      end
-    else
-      # rubocop:disable Lint/DuplicateMethods
-      attr_accessor :source
-      # rubocop:enable Lint/DuplicateMethods
+    remove_method :source
+    attr_writer :source
+    def source
+      (defined?(@source) && @source) || Gem::Source::Installed.new
     end
 
     alias_method :rg_full_gem_path, :full_gem_path
     alias_method :rg_loaded_from,   :loaded_from
 
-    attr_writer :full_gem_path unless instance_methods.include?(:full_gem_path=)
-
     def full_gem_path
       # this cannot check source.is_a?(Bundler::Plugin::API::Source)
       # because that _could_ trip the autoload, and if there are unresolved
diff --git a/lib/bundler/rubygems_integration.rb b/lib/bundler/rubygems_integration.rb
index a4519246a9..ca7dd32611 100644
--- a/lib/bundler/rubygems_integration.rb
+++ b/lib/bundler/rubygems_integration.rb
@@ -20,6 +20,7 @@ module Bundler
 
     def initialize
       @replaced_methods = {}
+      backport_ext_builder_monitor
     end
 
     def version
@@ -198,10 +199,6 @@ module Bundler
       Gem::ConfigMap
     end
 
-    def repository_subdirectories
-      %w[cache doc gems specifications]
-    end
-
     def clear_paths
       Gem.clear_paths
     end
@@ -210,10 +207,6 @@ module Bundler
       Gem.bin_path(gem, bin, ver)
     end
 
-    def path_separator
-      File::PATH_SEPARATOR
-    end
-
     def preserve_paths
       # this is a no-op outside of RubyGems 1.8
       yield
@@ -248,36 +241,12 @@ module Bundler
       EXT_LOCK
     end
 
-    def fetch_specs(all, pre, &blk)
-      require "rubygems/spec_fetcher"
-      specs = Gem::SpecFetcher.new.list(all, pre)
-      specs.each { yield } if block_given?
-      specs
-    end
-
     def fetch_prerelease_specs
       fetch_specs(false, true)
     rescue Gem::RemoteFetcher::FetchError
       {} # if we can't download them, there aren't any
     end
 
-    # TODO: This is for older versions of RubyGems... should we support the
-    # X-Gemfile-Source header on these old versions?
-    # Maybe the newer implementation will work on older RubyGems?
-    # It seems difficult to keep this implementation and still send the header.
-    def fetch_all_remote_specs(remote)
-      old_sources = Bundler.rubygems.sources
-      Bundler.rubygems.sources = [remote.uri.to_s]
-      # Fetch all specs, minus prerelease specs
-      spec_list = fetch_specs(true, false)
-      # Then fetch the prerelease specs
-      fetch_prerelease_specs.each {|k, v| spec_list[k].concat(v) }
-
-      spec_list.values.first
-    ensure
-      Bundler.rubygems.sources = old_sources
-    end
-
     def with_build_args(args)
       ext_lock.synchronize do
         old_args = build_args
@@ -290,15 +259,6 @@ module Bundler
       end
     end
 
-    def install_with_build_args(args)
-      with_build_args(args) { yield }
-    end
-
-    def gem_from_path(path, policy = nil)
-      require "rubygems/format"
-      Gem::Format.from_file_by_path(path, policy)
-    end
-
     def spec_from_gem(path, policy = nil)
       require "rubygems/security"
       require "bundler/psyched_yaml"
@@ -317,23 +277,10 @@ module Bundler
       end
     end
 
-    def build(spec, skip_validation = false)
-      require "rubygems/builder"
-      Gem::Builder.new(spec).build
-    end
-
     def build_gem(gem_dir, spec)
       build(spec)
     end
 
-    def download_gem(spec, uri, path)
-      uri = Bundler.settings.mirror_for(uri)
-      fetcher = Gem::RemoteFetcher.new(configuration[:http_proxy])
-      Bundler::Retry.new("download gem from #{uri}").attempts do
-        fetcher.download(spec, uri, path)
-      end
-    end
-
     def security_policy_keys
       %w[High Medium Low AlmostNo No].map {|level| "#{level}Security" }
     end
@@ -357,12 +304,27 @@ module Bundler
       end
     end
 
-    def binstubs_call_gem?
-      true
-    end
+    if provides?(">= 2.5.2")
+      # RubyGems-generated binstubs call Kernel#gem
+      def binstubs_call_gem?
+        false
+      end
+
+      # only 2.5.2+ has all of the stub methods we want to use, and since this
+      # is a performance optimization _only_,
+      # we'll restrict ourselves to the most
+      # recent RG versions instead of all versions that have stubs
+      def stubs_provide_full_functionality?
+        true
+      end
+    else
+      def binstubs_call_gem?
+        true
+      end
 
-    def stubs_provide_full_functionality?
-      false
+      def stubs_provide_full_functionality?
+        false
+      end
     end
 
     def replace_gem(specs, specs_by_name)
@@ -411,26 +373,6 @@ module Bundler
       end
     end
 
-    def stub_source_index(specs)
-      Gem::SourceIndex.send(:alias_method, :old_initialize, :initialize)
-      redefine_method(Gem::SourceIndex, :initialize) do |*args|
-        @gems = {}
-        # You're looking at this thinking: Oh! This is how I make those
-        # rubygems deprecations go away!
-        #
-        # You'd be correct BUT using of this method in production code
-        # must be approved by the rubygems team itself!
-        #
-        # This is your warning. If you use this and don't have approval
-        # we can't protect you.
-        #
-        Deprecate.skip_during do
-          self.spec_dirs = *args
-          add_specs(*specs)
-        end
-      end
-    end
-
     # Used to make bin stubs that are not created by bundler work
     # under bundler. The new Gem.bin_path only considers gems in
     # +specs+
@@ -622,296 +564,137 @@ module Bundler
       end
     end
 
-    # RubyGems 1.4 through 1.6
-    class Legacy < RubygemsIntegration
-      def initialize
-        super
-        backport_base_dir
-        backport_cache_file
-        backport_spec_file
-        backport_yaml_initialize
-      end
+    def stub_rubygems(specs)
+      Gem::Specification.all = specs
 
-      def stub_rubygems(specs)
-        # RubyGems versions lower than 1.7 use SourceIndex#from_gems_in
-        source_index_class = (class << Gem::SourceIndex; self; end)
-        redefine_method(source_index_class, :from_gems_in) do |*args|
-          Gem::SourceIndex.new.tap do |source_index|
-            source_index.spec_dirs = *args
-            source_index.add_specs(*specs)
-          end
-        end
+      Gem.post_reset do
+        Gem::Specification.all = specs
       end
 
-      def all_specs
-        Gem.source_index.gems.values
+      redefine_method((class << Gem; self; end), :finish_resolve) do |*|
+        []
       end
+    end
 
-      def find_name(name)
-        Gem.source_index.find_name(name)
-      end
+    def fetch_specs(source, remote, name)
+      path = source + "#{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)
+      Bundler.load_marshal(string)
+    rescue Gem::RemoteFetcher::FetchError => e
+      # it's okay for prerelease to fail
+      raise e unless name == "prerelease_specs"
+    end
 
-      def validate(spec)
-        # These versions of RubyGems always validate in "packaging" mode,
-        # which is too strict for the kinds of checks we care about. As a
-        # result, validation is disabled on versions of RubyGems below 1.7.
-      end
+    def fetch_all_remote_specs(remote)
+      source = remote.uri.is_a?(URI) ? remote.uri : URI.parse(source.to_s)
 
-      def post_reset_hooks
-        []
-      end
+      specs = fetch_specs(source, remote, "specs")
+      pres = fetch_specs(source, remote, "prerelease_specs") || []
 
-      def reset
-      end
+      specs.concat(pres)
     end
 
-    # RubyGems versions 1.3.6 and 1.3.7
-    class Ancient < Legacy
-      def initialize
-        super
-        backport_segment_generation
+    def download_gem(spec, uri, path)
+      uri = Bundler.settings.mirror_for(uri)
+      fetcher = gem_remote_fetcher
+      fetcher.headers = { "X-Gemfile-Source" => spec.remote.original_uri.to_s } if spec.remote.original_uri
+      Bundler::Retry.new("download gem from #{uri}").attempts do
+        fetcher.download(spec, uri, path)
       end
     end
 
-    # RubyGems 1.7
-    class Transitional < Legacy
-      def stub_rubygems(specs)
-        stub_source_index(specs)
-      end
-
-      def validate(spec)
-        # Missing summary is downgraded to a warning in later versions,
-        # so we set it to an empty string to prevent an exception here.
-        spec.summary ||= ""
-        RubygemsIntegration.instance_method(:validate).bind(self).call(spec)
-      end
+    def gem_remote_fetcher
+      require "resolv"
+      proxy = configuration[:http_proxy]
+      dns = Resolv::DNS.new
+      Bundler::GemRemoteFetcher.new(proxy, dns)
     end
 
-    # RubyGems 1.8.5-1.8.19
-    class Modern < RubygemsIntegration
-      def stub_rubygems(specs)
-        Gem::Specification.all = specs
-
-        Gem.post_reset do
-          Gem::Specification.all = specs
-        end
+    def gem_from_path(path, policy = nil)
+      require "rubygems/package"
+      p = Gem::Package.new(path)
+      p.security_policy = policy if policy
+      p
+    end
 
-        stub_source_index(specs)
-      end
+    def build(spec, skip_validation = false)
+      require "rubygems/package"
+      Gem::Package.build(spec, skip_validation)
+    end
 
-      def all_specs
-        Gem::Specification.to_a
-      end
+    def repository_subdirectories
+      Gem::REPOSITORY_SUBDIRECTORIES
+    end
 
-      def find_name(name)
-        Gem::Specification.find_all_by_name name
-      end
+    def install_with_build_args(args)
+      yield
     end
 
-    # RubyGems 1.8.0 to 1.8.4
-    class AlmostModern < Modern
-      # RubyGems [>= 1.8.0, < 1.8.5] has a bug that changes Gem.dir whenever
-      # you call Gem::Installer#install with an :install_dir set. We have to
-      # change it back for our sudo mode to work.
-      def preserve_paths
-        old_dir = gem_dir
-        old_path = gem_path
-        yield
-        Gem.use_paths(old_dir, old_path)
-      end
+    def path_separator
+      Gem.path_separator
     end
 
-    # RubyGems 1.8.20+
-    class MoreModern < Modern
-      # RubyGems 1.8.20 and adds the skip_validation parameter, so that's
-      # when we start passing it through.
-      def build(spec, skip_validation = false)
-        require "rubygems/builder"
-        Gem::Builder.new(spec).build(skip_validation)
+    def all_specs
+      require "bundler/remote_specification"
+      Gem::Specification.stubs.map do |stub|
+        StubSpecification.from_stub(stub)
       end
     end
 
-    # RubyGems 2.0
-    class Future < RubygemsIntegration
-      def stub_rubygems(specs)
-        Gem::Specification.all = specs
-
-        Gem.post_reset do
-          Gem::Specification.all = specs
-        end
-
-        redefine_method((class << Gem; self; end), :finish_resolve) do |*|
-          []
+    def backport_ext_builder_monitor
+      # So we can avoid requiring "rubygems/ext" in its entirety
+      Gem.module_eval <<-RB, __FILE__, __LINE__ + 1
+        module Ext
         end
-      end
+      RB
 
-      def all_specs
-        Gem::Specification.to_a
-      end
+      require "rubygems/ext/builder"
 
-      def find_name(name)
-        Gem::Specification.find_all_by_name name
-      end
-
-      def fetch_specs(source, remote, name)
-        path = source + "#{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)
-        Bundler.load_marshal(string)
-      rescue Gem::RemoteFetcher::FetchError => e
-        # it's okay for prerelease to fail
-        raise e unless name == "prerelease_specs"
-      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.concat(pres)
-      end
-
-      def download_gem(spec, uri, path)
-        uri = Bundler.settings.mirror_for(uri)
-        fetcher = gem_remote_fetcher
-        fetcher.headers = { "X-Gemfile-Source" => spec.remote.original_uri.to_s } if spec.remote.original_uri
-        Bundler::Retry.new("download gem from #{uri}").attempts do
-          fetcher.download(spec, uri, path)
+      Gem::Ext::Builder.class_eval do
+        unless const_defined?(:CHDIR_MONITOR)
+          const_set(:CHDIR_MONITOR, EXT_LOCK)
         end
-      end
-
-      def gem_remote_fetcher
-        require "resolv"
-        proxy = configuration[:http_proxy]
-        dns = Resolv::DNS.new
-        Bundler::GemRemoteFetcher.new(proxy, dns)
-      end
-
-      def gem_from_path(path, policy = nil)
-        require "rubygems/package"
-        p = Gem::Package.new(path)
-        p.security_policy = policy if policy
-        p
-      end
-
-      def build(spec, skip_validation = false)
-        require "rubygems/package"
-        Gem::Package.build(spec, skip_validation)
-      end
-
-      def repository_subdirectories
-        Gem::REPOSITORY_SUBDIRECTORIES
-      end
-
-      def install_with_build_args(args)
-        yield
-      end
 
-      def path_separator
-        Gem.path_separator
+        remove_const(:CHDIR_MUTEX) if const_defined?(:CHDIR_MUTEX)
+        const_set(:CHDIR_MUTEX, const_get(:CHDIR_MONITOR))
       end
     end
 
-    # RubyGems 2.1.0
-    class MoreFuture < Future
-      def initialize
-        super
-        backport_ext_builder_monitor
-      end
-
-      def all_specs
-        require "bundler/remote_specification"
-        Gem::Specification.stubs.map do |stub|
-          StubSpecification.from_stub(stub)
-        end
-      end
-
-      def backport_ext_builder_monitor
-        # So we can avoid requiring "rubygems/ext" in its entirety
-        Gem.module_eval <<-RB, __FILE__, __LINE__ + 1
-          module Ext
-          end
-        RB
-
-        require "rubygems/ext/builder"
-
-        Gem::Ext::Builder.class_eval do
-          unless const_defined?(:CHDIR_MONITOR)
-            const_set(:CHDIR_MONITOR, EXT_LOCK)
-          end
-
-          remove_const(:CHDIR_MUTEX) if const_defined?(:CHDIR_MUTEX)
-          const_set(:CHDIR_MUTEX, const_get(:CHDIR_MONITOR))
-        end
+    if Gem::Specification.respond_to?(:stubs_for)
+      def find_name(name)
+        Gem::Specification.stubs_for(name).map(&:to_spec)
       end
-
-      if Gem::Specification.respond_to?(:stubs_for)
-        def find_name(name)
-          Gem::Specification.stubs_for(name).map(&:to_spec)
-        end
-      else
-        def find_name(name)
-          Gem::Specification.stubs.find_all do |spec|
-            spec.name == name
-          end.map(&:to_spec)
-        end
+    else
+      def find_name(name)
+        Gem::Specification.stubs.find_all do |spec|
+          spec.name == name
+        end.map(&:to_spec)
       end
+    end
 
-      if Gem::Specification.respond_to?(:default_stubs)
-        def default_stubs
-          Gem::Specification.default_stubs("*.gemspec")
-        end
-      else
-        def default_stubs
-          Gem::Specification.send(:default_stubs, "*.gemspec")
-        end
+    if Gem::Specification.respond_to?(:default_stubs)
+      def default_stubs
+        Gem::Specification.default_stubs("*.gemspec")
       end
-
-      def use_gemdeps(gemfile)
-        ENV["BUNDLE_GEMFILE"] ||= File.expand_path(gemfile)
-        require "bundler/gemdeps"
-        runtime = Bundler.setup
-        Bundler.ui = nil
-        activated_spec_names = runtime.requested_specs.map(&:to_spec).sort_by(&:name)
-        [Gemdeps.new(runtime), activated_spec_names]
+    else
+      def default_stubs
+        Gem::Specification.send(:default_stubs, "*.gemspec")
       end
+    end
 
-      if provides?(">= 2.5.2")
-        # RubyGems-generated binstubs call Kernel#gem
-        def binstubs_call_gem?
-          false
-        end
-
-        # only 2.5.2+ has all of the stub methods we want to use, and since this
-        # is a performance optimization _only_,
-        # we'll restrict ourselves to the most
-        # recent RG versions instead of all versions that have stubs
-        def stubs_provide_full_functionality?
-          true
-        end
-      end
+    def use_gemdeps(gemfile)
+      ENV["BUNDLE_GEMFILE"] ||= File.expand_path(gemfile)
+      require "bundler/gemdeps"
+      runtime = Bundler.setup
+      Bundler.ui = nil
+      activated_spec_names = runtime.requested_specs.map(&:to_spec).sort_by(&:name)
+      [Gemdeps.new(runtime), activated_spec_names]
     end
   end
 
   def self.rubygems
-    @rubygems ||= if RubygemsIntegration.provides?(">= 2.1.0")
-      RubygemsIntegration::MoreFuture.new
-    elsif RubygemsIntegration.provides?(">= 1.99.99")
-      RubygemsIntegration::Future.new
-    elsif RubygemsIntegration.provides?(">= 1.8.20")
-      RubygemsIntegration::MoreModern.new
-    elsif RubygemsIntegration.provides?(">= 1.8.5")
-      RubygemsIntegration::Modern.new
-    elsif RubygemsIntegration.provides?(">= 1.8.0")
-      RubygemsIntegration::AlmostModern.new
-    elsif RubygemsIntegration.provides?(">= 1.7.0")
-      RubygemsIntegration::Transitional.new
-    elsif RubygemsIntegration.provides?(">= 1.4.0")
-      RubygemsIntegration::Legacy.new
-    else # RubyGems 1.3.6 and 1.3.7
-      RubygemsIntegration::Ancient.new
-    end
+    @rubygems ||= RubygemsIntegration.new
   end
 end