Merge RubyGems 3.5.5 and Bundler 2.5.5 (#9676)

* Merge RubyGems-3.5.4 and Bundler-2.5.4

* Merge RubyGems-3.5.5 and Bundler-2.5.5

* Make tests play with upstream Ruby tests

CI broke in https://github.com/ruby/ruby/pull/9604 because if any Ruby
tests run `require 'net/http'`, they will pollute the
`$LOADED_FEATURES` for the RubyGems tests. We can fix this by renaming
the test default gem from `net-http` to `my-http`.

See https://github.com/rubygems/rubygems/pull/7379#issuecomment-1901241299
for more details.

---------

Co-authored-by: Stan Hu <stanhu@gmail.com>

31 files changed, 323 insertions, 128 deletions

diff --git a/lib/bundler/compact_index_client/updater.rb b/lib/bundler/compact_index_client/updater.rb
index 84a606dc34..36f6b81db8 100644
--- a/lib/bundler/compact_index_client/updater.rb
+++ b/lib/bundler/compact_index_client/updater.rb
@@ -42,7 +42,7 @@ module Bundler
           else
             file.write(response.body)
           end
-          CacheFile.write(etag_path, etag(response))
+          CacheFile.write(etag_path, etag_from_response(response))
           true
         end
       end
@@ -53,13 +53,13 @@ module Bundler
         response = @fetcher.call(remote_path, request_headers(etag))
         return true if response.is_a?(Gem::Net::HTTPNotModified)
         CacheFile.write(local_path, response.body, parse_digests(response))
-        CacheFile.write(etag_path, etag(response))
+        CacheFile.write(etag_path, etag_from_response(response))
       end
 
       def request_headers(etag, range_start = nil)
         headers = {}
         headers["Range"] = "bytes=#{range_start}-" if range_start
-        headers["If-None-Match"] = etag if etag
+        headers["If-None-Match"] = %("#{etag}") if etag
         headers
       end
 
@@ -77,7 +77,7 @@ module Bundler
         etag
       end
 
-      def etag(response)
+      def etag_from_response(response)
         return unless response["ETag"]
         etag = response["ETag"].delete_prefix("W/")
         return if etag.delete_prefix!('"') && !etag.delete_suffix!('"')
diff --git a/lib/bundler/definition.rb b/lib/bundler/definition.rb
index 9b905db1f9..0b0e63f77e 100644
--- a/lib/bundler/definition.rb
+++ b/lib/bundler/definition.rb
@@ -312,10 +312,6 @@ module Bundler
       end
     end
 
-    def should_complete_platforms?
-      !lockfile_exists? && generic_local_platform_is_ruby? && !Bundler.settings[:force_ruby_platform]
-    end
-
     def spec_git_paths
       sources.git_sources.map {|s| File.realpath(s.path) if File.exist?(s.path) }.compact
     end
@@ -517,6 +513,10 @@ module Bundler
 
     private
 
+    def should_add_extra_platforms?
+      !lockfile_exists? && generic_local_platform_is_ruby? && !Bundler.settings[:force_ruby_platform]
+    end
+
     def lockfile_exists?
       lockfile && File.exist?(lockfile)
     end
@@ -600,7 +600,9 @@ module Bundler
       result = SpecSet.new(resolver.start)
 
       @resolved_bundler_version = result.find {|spec| spec.name == "bundler" }&.version
-      @platforms = result.complete_platforms!(platforms) if should_complete_platforms?
+      @platforms = result.add_extra_platforms!(platforms) if should_add_extra_platforms?
+
+      result.complete_platforms!(platforms)
 
       SpecSet.new(result.for(dependencies, false, @platforms))
     end
diff --git a/lib/bundler/dsl.rb b/lib/bundler/dsl.rb
index 1eca749617..1460b9f52f 100644
--- a/lib/bundler/dsl.rb
+++ b/lib/bundler/dsl.rb
@@ -102,9 +102,6 @@ module Bundler
 
       # if there's already a dependency with this name we try to prefer one
       if current = @dependencies.find {|d| d.name == dep.name }
-        # Always prefer the dependency from the Gemfile
-        @dependencies.delete(current) if current.gemspec_dev_dep?
-
         if current.requirement != dep.requirement
           current_requirement_open = current.requirements_list.include?(">= 0")
 
@@ -116,8 +113,6 @@ module Bundler
               Bundler.ui.warn "A gemspec development dependency (#{gemspec_dep.name}, #{gemspec_dep.requirement}) is being overridden by a Gemfile dependency (#{gemfile_dep.name}, #{gemfile_dep.requirement}).\n" \
                               "This behaviour may change in the future. Please remove either of them, or make sure they both have the same requirement\n"
             end
-
-            return if dep.gemspec_dev_dep?
           else
             update_prompt = ""
 
@@ -135,8 +130,13 @@ module Bundler
                            "You specified: #{current.name} (#{current.requirement}) and #{dep.name} (#{dep.requirement})" \
                            "#{update_prompt}"
           end
-        elsif current.gemspec_dev_dep? || dep.gemspec_dev_dep?
-          return if dep.gemspec_dev_dep?
+        end
+
+        # Always prefer the dependency from the Gemfile
+        if current.gemspec_dev_dep?
+          @dependencies.delete(current)
+        elsif dep.gemspec_dev_dep?
+          return
         elsif current.source != dep.source
           raise GemfileError, "You cannot specify the same gem twice coming from different sources.\n" \
                           "You specified that #{dep.name} (#{dep.requirement}) should come from " \
diff --git a/lib/bundler/man/bundle-config.1 b/lib/bundler/man/bundle-config.1
index 8090e03f7d..c5a976da46 100644
--- a/lib/bundler/man/bundle-config.1
+++ b/lib/bundler/man/bundle-config.1
@@ -302,9 +302,9 @@ Note that any configured credentials will be redacted by informative commands su
 .P
 Also note that to guarantee a sane mapping between valid environment variable names and valid host names, bundler makes the following transformations:
 .IP "\(bu" 4
-Any \fB\-\fR characters in a host name are mapped to a triple dash (\fB___\fR) in the corresponding environment variable\.
+Any \fB\-\fR characters in a host name are mapped to a triple underscore (\fB___\fR) in the corresponding environment variable\.
 .IP "\(bu" 4
-Any \fB\.\fR characters in a host name are mapped to a double dash (\fB__\fR) in the corresponding environment variable\.
+Any \fB\.\fR characters in a host name are mapped to a double underscore (\fB__\fR) in the corresponding environment variable\.
 .IP "" 0
 .P
 This means that if you have a gem server named \fBmy\.gem\-host\.com\fR, you'll need to use the \fBBUNDLE_MY__GEM___HOST__COM\fR variable to configure credentials for it through ENV\.
diff --git a/lib/bundler/man/bundle-config.1.ronn b/lib/bundler/man/bundle-config.1.ronn
index b935329b4e..587d31dbad 100644
--- a/lib/bundler/man/bundle-config.1.ronn
+++ b/lib/bundler/man/bundle-config.1.ronn
@@ -388,10 +388,10 @@ copy-pasting bundler output.
 Also note that to guarantee a sane mapping between valid environment variable
 names and valid host names, bundler makes the following transformations:
 
-* Any `-` characters in a host name are mapped to a triple dash (`___`) in the
+* Any `-` characters in a host name are mapped to a triple underscore (`___`) in the
   corresponding environment variable.
 
-* Any `.` characters in a host name are mapped to a double dash (`__`) in the
+* Any `.` characters in a host name are mapped to a double underscore (`__`) in the
   corresponding environment variable.
 
 This means that if you have a gem server named `my.gem-host.com`, you'll need to
diff --git a/lib/bundler/spec_set.rb b/lib/bundler/spec_set.rb
index ceaac2cec5..cc649abaf8 100644
--- a/lib/bundler/spec_set.rb
+++ b/lib/bundler/spec_set.rb
@@ -52,32 +52,14 @@ module Bundler
       specs.uniq
     end
 
-    def complete_platforms!(platforms)
+    def add_extra_platforms!(platforms)
       return platforms.concat([Gem::Platform::RUBY]).uniq if @specs.empty?
 
-      new_platforms = @specs.flat_map {|spec| spec.source.specs.search([spec.name, spec.version]).map(&:platform) }.uniq.select do |platform|
+      new_platforms = all_platforms.select do |platform|
         next if platforms.include?(platform)
         next unless GemHelpers.generic(platform) == Gem::Platform::RUBY
 
-        new_specs = []
-
-        valid_platform = lookup.all? do |_, specs|
-          spec = specs.first
-          matching_specs = spec.source.specs.search([spec.name, spec.version])
-          platform_spec = GemHelpers.select_best_platform_match(matching_specs, platform).find do |s|
-            s.matches_current_metadata? && valid_dependencies?(s)
-          end
-
-          if platform_spec
-            new_specs << LazySpecification.from_spec(platform_spec)
-            true
-          else
-            false
-          end
-        end
-        next unless valid_platform
-
-        @specs.concat(new_specs.uniq)
+        complete_platform(platform)
       end
       return platforms if new_platforms.empty?
 
@@ -86,12 +68,15 @@ module Bundler
       less_specific_platform = new_platforms.find {|platform| platform != Gem::Platform::RUBY && platform === Bundler.local_platform }
       platforms.delete(Bundler.local_platform) if less_specific_platform
 
-      @sorted = nil
-      @lookup = nil
-
       platforms
     end
 
+    def complete_platforms!(platforms)
+      platforms.each do |platform|
+        complete_platform(platform)
+      end
+    end
+
     def validate_deps(s)
       s.runtime_dependencies.each do |dep|
         next if dep.name == "bundler"
@@ -110,14 +95,14 @@ module Bundler
 
     def []=(key, value)
       @specs << value
-      @lookup = nil
-      @sorted = nil
+
+      reset!
     end
 
     def delete(specs)
       specs.each {|spec| @specs.delete(spec) }
-      @lookup = nil
-      @sorted = nil
+
+      reset!
     end
 
     def sort!
@@ -175,8 +160,8 @@ module Bundler
 
     def delete_by_name(name)
       @specs.reject! {|spec| spec.name == name }
-      @lookup = nil
-      @sorted = nil
+
+      reset!
     end
 
     def what_required(spec)
@@ -212,6 +197,42 @@ module Bundler
 
     private
 
+    def reset!
+      @sorted = nil
+      @lookup = nil
+    end
+
+    def complete_platform(platform)
+      new_specs = []
+
+      valid_platform = lookup.all? do |_, specs|
+        spec = specs.first
+        matching_specs = spec.source.specs.search([spec.name, spec.version])
+        platform_spec = GemHelpers.select_best_platform_match(matching_specs, platform).find do |s|
+          s.matches_current_metadata? && valid_dependencies?(s)
+        end
+
+        if platform_spec
+          new_specs << LazySpecification.from_spec(platform_spec) unless specs.include?(platform_spec)
+          true
+        else
+          false
+        end
+      end
+
+      if valid_platform && new_specs.any?
+        @specs.concat(new_specs)
+
+        reset!
+      end
+
+      valid_platform
+    end
+
+    def all_platforms
+      @specs.flat_map {|spec| spec.source.specs.search([spec.name, spec.version]).map(&:platform) }.uniq
+    end
+
     def valid_dependencies?(s)
       validate_deps(s) == :valid
     end
diff --git a/lib/bundler/version.rb b/lib/bundler/version.rb
index a0ef931d07..05b6c66ce4 100644
--- a/lib/bundler/version.rb
+++ b/lib/bundler/version.rb
@@ -1,7 +1,7 @@
 # frozen_string_literal: false
 
 module Bundler
-  VERSION = "2.5.3".freeze
+  VERSION = "2.5.5".freeze
 
   def self.bundler_major_version
     @bundler_major_version ||= VERSION.split(".").first.to_i
diff --git a/lib/rubygems.rb b/lib/rubygems.rb
index fa3da5cc1a..d4138b2d8f 100644
--- a/lib/rubygems.rb
+++ b/lib/rubygems.rb
@@ -9,7 +9,7 @@
 require "rbconfig"
 
 module Gem
-  VERSION = "3.5.3"
+  VERSION = "3.5.5"
 end
 
 # Must be first since it unloads the prelude from 1.9.2
@@ -1216,6 +1216,13 @@ An Array (#{env.inspect}) was passed in from #{caller[3]}
     ##
     # Find a Gem::Specification of default gem from +path+
 
+    def find_default_spec(path)
+      @path_to_default_spec_map[path]
+    end
+
+    ##
+    # Find an unresolved Gem::Specification of default gem from +path+
+
     def find_unresolved_default_spec(path)
       default_spec = @path_to_default_spec_map[path]
       return default_spec if default_spec && loaded_specs[default_spec.name] != default_spec
diff --git a/lib/rubygems/commands/update_command.rb b/lib/rubygems/commands/update_command.rb
index 10ae6d9a93..3d6fecaa40 100644
--- a/lib/rubygems/commands/update_command.rb
+++ b/lib/rubygems/commands/update_command.rb
@@ -244,7 +244,7 @@ command to remove old versions.
 
     @installer = Gem::DependencyInstaller.new update_options
 
-    say "Updating #{name}" unless options[:system] && options[:silent]
+    say "Updating #{name}" unless options[:system]
     begin
       @installer.install name, Gem::Requirement.new(version)
     rescue Gem::InstallError, Gem::DependencyError => e
@@ -282,7 +282,7 @@ command to remove old versions.
     check_oldest_rubygems version
 
     installed_gems = Gem::Specification.find_all_by_name "rubygems-update", requirement
-    installed_gems = update_gem("rubygems-update", version) if installed_gems.empty? || installed_gems.first.version != version
+    installed_gems = update_gem("rubygems-update", requirement) if installed_gems.empty? || installed_gems.first.version != version
     return if installed_gems.empty?
 
     install_rubygems installed_gems.first
@@ -294,9 +294,7 @@ command to remove old versions.
     args << "--prefix" << Gem.prefix if Gem.prefix
     args << "--no-document" unless options[:document].include?("rdoc") || options[:document].include?("ri")
     args << "--no-format-executable" if options[:no_format_executable]
-    args << "--previous-version" << Gem::VERSION if
-      options[:system] == true ||
-      Gem::Version.new(options[:system]) >= Gem::Version.new(2)
+    args << "--previous-version" << Gem::VERSION
     args
   end
 
diff --git a/lib/rubygems/core_ext/kernel_require.rb b/lib/rubygems/core_ext/kernel_require.rb
index bbd7852e92..073966b696 100644
--- a/lib/rubygems/core_ext/kernel_require.rb
+++ b/lib/rubygems/core_ext/kernel_require.rb
@@ -39,7 +39,14 @@ module Kernel
     RUBYGEMS_ACTIVATION_MONITOR.synchronize do
       path = File.path(path)
 
-      if spec = Gem.find_unresolved_default_spec(path)
+      # If +path+ belongs to a default gem, we activate it and then go straight
+      # to normal require
+
+      if spec = Gem.find_default_spec(path)
+        name = spec.name
+
+        next if Gem.loaded_specs[name]
+
         # Ensure -I beats a default gem
         resolved_path = begin
           rp = nil
@@ -57,8 +64,10 @@ module Kernel
           rp
         end
 
-        Kernel.send(:gem, spec.name, Gem::Requirement.default_prerelease) unless
+        Kernel.send(:gem, name, Gem::Requirement.default_prerelease) unless
           resolved_path
+
+        next
       end
 
       # If there are no unresolved deps, then we can use just try
diff --git a/lib/rubygems/defaults.rb b/lib/rubygems/defaults.rb
index 00dc5707c3..19cf306f88 100644
--- a/lib/rubygems/defaults.rb
+++ b/lib/rubygems/defaults.rb
@@ -24,7 +24,7 @@ module Gem
     default_spec_cache_dir = File.join Gem.user_home, ".gem", "specs"
 
     unless File.exist?(default_spec_cache_dir)
-      default_spec_cache_dir = File.join Gem.data_home, "gem", "specs"
+      default_spec_cache_dir = File.join Gem.cache_home, "gem", "specs"
     end
 
     default_spec_cache_dir
diff --git a/lib/rubygems/specification.rb b/lib/rubygems/specification.rb
index a0c7faa133..169002d7c7 100644
--- a/lib/rubygems/specification.rb
+++ b/lib/rubygems/specification.rb
@@ -301,7 +301,7 @@ class Gem::Specification < Gem::BasicSpecification
   #
   # Usage:
   #
-  #   spec.description = <<-EOF
+  #   spec.description = <<~EOF
   #     Rake is a Make-like program implemented in Ruby. Tasks and
   #     dependencies are specified in standard Ruby syntax.
   #   EOF
diff --git a/spec/bundler/bundler/compact_index_client/updater_spec.rb b/spec/bundler/bundler/compact_index_client/updater_spec.rb
index 51b838d2d2..6eed88ca9e 100644
--- a/spec/bundler/bundler/compact_index_client/updater_spec.rb
+++ b/spec/bundler/bundler/compact_index_client/updater_spec.rb
@@ -21,7 +21,7 @@ RSpec.describe Bundler::CompactIndexClient::Updater do
     before do
       allow(response).to receive(:[]).with("Repr-Digest") { nil }
       allow(response).to receive(:[]).with("Digest") { nil }
-      allow(response).to receive(:[]).with("ETag") { "thisisanetag" }
+      allow(response).to receive(:[]).with("ETag") { '"thisisanetag"' }
     end
 
     it "downloads the file without attempting append" do
@@ -57,7 +57,7 @@ RSpec.describe Bundler::CompactIndexClient::Updater do
 
       let(:headers) do
         {
-          "If-None-Match" => "LocalEtag",
+          "If-None-Match" => '"LocalEtag"',
           "Range" => "bytes=2-",
         }
       end
@@ -76,7 +76,7 @@ RSpec.describe Bundler::CompactIndexClient::Updater do
       it "appends the file if etags do not match" do
         expect(fetcher).to receive(:call).once.with(remote_path, headers).and_return(response)
         allow(response).to receive(:[]).with("Repr-Digest") { "sha-256=:#{digest}:" }
-        allow(response).to receive(:[]).with("ETag") { "NewEtag" }
+        allow(response).to receive(:[]).with("ETag") { '"NewEtag"' }
         allow(response).to receive(:is_a?).with(Gem::Net::HTTPPartialContent) { true }
         allow(response).to receive(:is_a?).with(Gem::Net::HTTPNotModified) { false }
         allow(response).to receive(:body) { "c123" }
@@ -90,7 +90,7 @@ RSpec.describe Bundler::CompactIndexClient::Updater do
       it "replaces the file if response ignores range" do
         expect(fetcher).to receive(:call).once.with(remote_path, headers).and_return(response)
         allow(response).to receive(:[]).with("Repr-Digest") { "sha-256=:#{digest}:" }
-        allow(response).to receive(:[]).with("ETag") { "NewEtag" }
+        allow(response).to receive(:[]).with("ETag") { '"NewEtag"' }
         allow(response).to receive(:body) { full_body }
 
         updater.update(remote_path, local_path, etag_path)
@@ -107,8 +107,8 @@ RSpec.describe Bundler::CompactIndexClient::Updater do
 
         full_response = double(:full_response, body: full_body, is_a?: false)
         allow(full_response).to receive(:[]).with("Repr-Digest") { "sha-256=:#{digest}:" }
-        allow(full_response).to receive(:[]).with("ETag") { "NewEtag" }
-        expect(fetcher).to receive(:call).once.with(remote_path, { "If-None-Match" => "LocalEtag" }).and_return(full_response)
+        allow(full_response).to receive(:[]).with("ETag") { '"NewEtag"' }
+        expect(fetcher).to receive(:call).once.with(remote_path, { "If-None-Match" => '"LocalEtag"' }).and_return(full_response)
 
         updater.update(remote_path, local_path, etag_path)
 
@@ -123,7 +123,7 @@ RSpec.describe Bundler::CompactIndexClient::Updater do
           "Range" => "bytes=2-",
           # This MD5 feature should be deleted after sufficient time has passed since release.
           # From then on, requests that still don't have a saved etag will be made without this header.
-          "If-None-Match" => Digest::MD5.hexdigest(local_body),
+          "If-None-Match" => %("#{Digest::MD5.hexdigest(local_body)}"),
         }
       end
 
@@ -135,13 +135,13 @@ RSpec.describe Bundler::CompactIndexClient::Updater do
         updater.update(remote_path, local_path, etag_path)
 
         expect(local_path.read).to eq("abc")
-        expect(etag_path.read).to eq(headers["If-None-Match"])
+        expect(%("#{etag_path.read}")).to eq(headers["If-None-Match"])
       end
 
       it "appends the file" do
         expect(fetcher).to receive(:call).once.with(remote_path, headers).and_return(response)
         allow(response).to receive(:[]).with("Repr-Digest") { "sha-256=:#{digest}:" }
-        allow(response).to receive(:[]).with("ETag") { "OpaqueEtag" }
+        allow(response).to receive(:[]).with("ETag") { '"OpaqueEtag"' }
         allow(response).to receive(:is_a?).with(Gem::Net::HTTPPartialContent) { true }
         allow(response).to receive(:is_a?).with(Gem::Net::HTTPNotModified) { false }
         allow(response).to receive(:body) { "c123" }
@@ -156,7 +156,7 @@ RSpec.describe Bundler::CompactIndexClient::Updater do
         expect(fetcher).to receive(:call).once.with(remote_path, headers).and_return(response)
         allow(response).to receive(:[]).with("Repr-Digest") { nil }
         allow(response).to receive(:[]).with("Digest") { nil }
-        allow(response).to receive(:[]).with("ETag") { "OpaqueEtag" }
+        allow(response).to receive(:[]).with("ETag") { '"OpaqueEtag"' }
         allow(response).to receive(:is_a?).with(Gem::Net::HTTPPartialContent) { false }
         allow(response).to receive(:is_a?).with(Gem::Net::HTTPNotModified) { false }
         allow(response).to receive(:body) { full_body }
@@ -180,8 +180,8 @@ RSpec.describe Bundler::CompactIndexClient::Updater do
 
         full_response = double(:full_response, body: full_body, is_a?: false)
         allow(full_response).to receive(:[]).with("Repr-Digest") { "sha-256=:#{digest}:" }
-        allow(full_response).to receive(:[]).with("ETag") { "NewEtag" }
-        expect(fetcher).to receive(:call).once.with(remote_path, { "If-None-Match" => "LocalEtag" }).and_return(full_response)
+        allow(full_response).to receive(:[]).with("ETag") { '"NewEtag"' }
+        expect(fetcher).to receive(:call).once.with(remote_path, { "If-None-Match" => '"LocalEtag"' }).and_return(full_response)
 
         updater.update(remote_path, local_path, etag_path)
 
diff --git a/spec/bundler/commands/install_spec.rb b/spec/bundler/commands/install_spec.rb
index 7c016ff3d8..f0c9aaea8e 100644
--- a/spec/bundler/commands/install_spec.rb
+++ b/spec/bundler/commands/install_spec.rb
@@ -460,6 +460,35 @@ RSpec.describe "bundle install with gem sources" do
       expect(the_bundle).to include_gems("rubocop 1.37.1")
     end
 
+    it "includes the gem without warning if two gemspecs add it with the same requirement" do
+      gem1 = tmp.join("my-gem-1")
+      gem2 = tmp.join("my-gem-2")
+
+      build_lib "my-gem", path: gem1 do |s|
+        s.add_development_dependency "rubocop", "~> 1.36.0"
+      end
+
+      build_lib "my-gem-2", path: gem2 do |s|
+        s.add_development_dependency "rubocop", "~> 1.36.0"
+      end
+
+      build_repo4 do
+        build_gem "rubocop", "1.36.0"
+      end
+
+      gemfile <<~G
+        source "#{file_uri_for(gem_repo4)}"
+
+        gemspec path: "#{gem1}"
+        gemspec path: "#{gem2}"
+      G
+
+      bundle :install
+
+      expect(err).to be_empty
+      expect(the_bundle).to include_gems("rubocop 1.36.0")
+    end
+
     it "warns when a Gemfile dependency is overriding a gemspec development dependency, with different requirements" do
       build_lib "my-gem", path: bundled_app do |s|
         s.add_development_dependency "rails", ">= 5"
diff --git a/spec/bundler/commands/update_spec.rb b/spec/bundler/commands/update_spec.rb
index 59e7c3867c..2bde5a1586 100644
--- a/spec/bundler/commands/update_spec.rb
+++ b/spec/bundler/commands/update_spec.rb
@@ -1380,7 +1380,7 @@ RSpec.describe "bundle update --bundler" do
       build_bundler "999.0.0"
     end
 
-    install_gemfile <<-G
+    install_gemfile <<-G, artifice: nil, env: { "BUNDLER_IGNORE_DEFAULT_GEM" => "true" }
       source "#{file_uri_for(gem_repo4)}"
       gem "rack"
     G
diff --git a/spec/bundler/install/gems/compact_index_spec.rb b/spec/bundler/install/gems/compact_index_spec.rb
index e3c891e4c1..1375d8cab1 100644
--- a/spec/bundler/install/gems/compact_index_spec.rb
+++ b/spec/bundler/install/gems/compact_index_spec.rb
@@ -924,15 +924,19 @@ RSpec.describe "compact index api" do
       gem 'rack', '0.9.1'
     G
 
-    rake_info_path = File.join(Bundler.rubygems.user_home, ".bundle", "cache", "compact_index",
-      "localgemserver.test.80.dd34752a738ee965a2a4298dc16db6c5", "info", "rack")
-
     bundle :install, artifice: "compact_index"
 
+    # We must remove the etag so that we don't ignore the range and get a 304 Not Modified.
+    rake_info_etag_path = File.join(Bundler.rubygems.user_home, ".bundle", "cache", "compact_index",
+      "localgemserver.test.80.dd34752a738ee965a2a4298dc16db6c5", "info-etags", "rack-11690b09f16021ff06a6857d784a1870")
+    File.unlink(rake_info_etag_path) if File.exist?(rake_info_etag_path)
+
+    rake_info_path = File.join(Bundler.rubygems.user_home, ".bundle", "cache", "compact_index",
+      "localgemserver.test.80.dd34752a738ee965a2a4298dc16db6c5", "info", "rack")
     expected_rack_info_content = File.read(rake_info_path)
 
-    # Modify the cache files. We expect them to be reset to the normal ones when we re-run :install
-    File.open(rake_info_path, "a") {|f| f << "this is different" }
+    # Modify the cache files to make the range not satisfiable
+    File.open(rake_info_path, "a") {|f| f << "0.9.2 |checksum:c55b525b421fd833a93171ad3d7f04528ca8e87d99ac273f8933038942a5888c" }
 
     # Update the Gemfile so the next install does its normal things
     gemfile <<-G
diff --git a/spec/bundler/lock/lockfile_spec.rb b/spec/bundler/lock/lockfile_spec.rb
index 5e996f5aac..7f664abc4d 100644
--- a/spec/bundler/lock/lockfile_spec.rb
+++ b/spec/bundler/lock/lockfile_spec.rb
@@ -1195,6 +1195,46 @@ RSpec.describe "the lockfile format" do
     G
   end
 
+  it "adds compatible platform specific variants to the lockfile, even if resolution fallback to RUBY due to some other incompatible platform specific variant" do
+    simulate_platform "arm64-darwin-23" do
+      build_repo4 do
+        build_gem "google-protobuf", "3.25.1"
+        build_gem "google-protobuf", "3.25.1" do |s|
+          s.platform = "arm64-darwin-23"
+        end
+        build_gem "google-protobuf", "3.25.1" do |s|
+          s.platform = "x64-mingw-ucrt"
+          s.required_ruby_version = "> #{Gem.ruby_version}"
+        end
+      end
+
+      gemfile <<-G
+        source "#{file_uri_for(gem_repo4)}"
+        gem "google-protobuf"
+      G
+      bundle "lock --add-platform x64-mingw-ucrt"
+
+      expect(lockfile).to eq <<~L
+        GEM
+          remote: #{file_uri_for(gem_repo4)}/
+          specs:
+            google-protobuf (3.25.1)
+            google-protobuf (3.25.1-arm64-darwin-23)
+
+        PLATFORMS
+          arm64-darwin-23
+          ruby
+          x64-mingw-ucrt
+
+        DEPENDENCIES
+          google-protobuf
+
+        BUNDLED WITH
+           #{Bundler::VERSION}
+      L
+    end
+  end
+
   it "persists the spec's specific platform to the lockfile" do
     build_repo2 do
       build_gem "platform_specific", "1.0" do |s|
diff --git a/spec/bundler/support/artifice/endpoint_500.rb b/spec/bundler/support/artifice/endpoint_500.rb
index d8ab6b65bc..b1ed1964c8 100644
--- a/spec/bundler/support/artifice/endpoint_500.rb
+++ b/spec/bundler/support/artifice/endpoint_500.rb
@@ -2,7 +2,7 @@
 
 require_relative "../path"
 
-$LOAD_PATH.unshift(*Dir[Spec::Path.base_system_gem_path.join("gems/{mustermann,rack,tilt,sinatra,ruby2_keywords}-*/lib")].map(&:to_s))
+$LOAD_PATH.unshift(*Dir[Spec::Path.base_system_gem_path.join("gems/{mustermann,rack,tilt,sinatra,ruby2_keywords,base64}-*/lib")].map(&:to_s))
 
 require "sinatra/base"
 
diff --git a/spec/bundler/support/artifice/helpers/compact_index.rb b/spec/bundler/support/artifice/helpers/compact_index.rb
index cf8bb34c5a..a803a2d30a 100644
--- a/spec/bundler/support/artifice/helpers/compact_index.rb
+++ b/spec/bundler/support/artifice/helpers/compact_index.rb
@@ -19,8 +19,8 @@ class CompactIndexAPI < Endpoint
     def etag_response
       response_body = yield
       etag = Digest::MD5.hexdigest(response_body)
-      return if not_modified?(etag)
       headers "ETag" => quote(etag)
+      return if not_modified?(etag)
       headers "Repr-Digest" => "sha-256=:#{Digest::SHA256.base64digest(response_body)}:"
       headers "Surrogate-Control" => "max-age=2592000, stale-while-revalidate=60"
       content_type "text/plain"
@@ -35,7 +35,6 @@ class CompactIndexAPI < Endpoint
       etags = parse_etags(request.env["HTTP_IF_NONE_MATCH"])
 
       return unless etags.include?(etag)
-      headers "ETag" => quote(etag)
       status 304
       body ""
     end
diff --git a/spec/bundler/support/artifice/helpers/endpoint.rb b/spec/bundler/support/artifice/helpers/endpoint.rb
index be52df6936..83ba1be0fc 100644
--- a/spec/bundler/support/artifice/helpers/endpoint.rb
+++ b/spec/bundler/support/artifice/helpers/endpoint.rb
@@ -2,7 +2,7 @@
 
 require_relative "../../path"
 
-$LOAD_PATH.unshift(*Dir[Spec::Path.base_system_gem_path.join("gems/{mustermann,rack,tilt,sinatra,ruby2_keywords}-*/lib")].map(&:to_s))
+$LOAD_PATH.unshift(*Dir[Spec::Path.base_system_gem_path.join("gems/{mustermann,rack,tilt,sinatra,ruby2_keywords,base64}-*/lib")].map(&:to_s))
 
 require "sinatra/base"
 
diff --git a/spec/bundler/support/artifice/windows.rb b/spec/bundler/support/artifice/windows.rb
index 4d90e0a426..fea991c071 100644
--- a/spec/bundler/support/artifice/windows.rb
+++ b/spec/bundler/support/artifice/windows.rb
@@ -2,7 +2,7 @@
 
 require_relative "../path"
 
-$LOAD_PATH.unshift(*Dir[Spec::Path.base_system_gem_path.join("gems/{mustermann,rack,tilt,sinatra,ruby2_keywords}-*/lib")].map(&:to_s))
+$LOAD_PATH.unshift(*Dir[Spec::Path.base_system_gem_path.join("gems/{mustermann,rack,tilt,sinatra,ruby2_keywords,base64}-*/lib")].map(&:to_s))
 
 require "sinatra/base"
 
diff --git a/spec/bundler/support/rubygems_ext.rb b/spec/bundler/support/rubygems_ext.rb
index c242e3a528..0d1ad2d528 100644
--- a/spec/bundler/support/rubygems_ext.rb
+++ b/spec/bundler/support/rubygems_ext.rb
@@ -86,7 +86,7 @@ module Spec
         puts success_message
         puts
       else
-        system("git status --porcelain")
+        system("git diff")
 
         puts
         puts error_message
diff --git a/test/rubygems/helper.rb b/test/rubygems/helper.rb
index d259fbde1b..e6774ded38 100644
--- a/test/rubygems/helper.rb
+++ b/test/rubygems/helper.rb
@@ -105,39 +105,32 @@ class Gem::TestCase < Test::Unit::TestCase
     refute File.directory?(path), msg
   end
 
-  # https://github.com/seattlerb/minitest/blob/21d9e804b63c619f602f3f4ece6c71b48974707a/lib/minitest/assertions.rb#L188
-  def _synchronize
-    yield
-  end
-
-  # https://github.com/seattlerb/minitest/blob/21d9e804b63c619f602f3f4ece6c71b48974707a/lib/minitest/assertions.rb#L546
+  # Originally copied from minitest/assertions.rb
   def capture_subprocess_io
-    _synchronize do
-      require "tempfile"
+    require "tempfile"
 
-      captured_stdout = Tempfile.new("out")
-      captured_stderr = Tempfile.new("err")
+    captured_stdout = Tempfile.new("out")
+    captured_stderr = Tempfile.new("err")
 
-      orig_stdout = $stdout.dup
-      orig_stderr = $stderr.dup
-      $stdout.reopen captured_stdout
-      $stderr.reopen captured_stderr
+    orig_stdout = $stdout.dup
+    orig_stderr = $stderr.dup
+    $stdout.reopen captured_stdout
+    $stderr.reopen captured_stderr
 
-      yield
+    yield
 
-      $stdout.rewind
-      $stderr.rewind
+    $stdout.rewind
+    $stderr.rewind
 
-      return captured_stdout.read, captured_stderr.read
-    ensure
-      $stdout.reopen orig_stdout
-      $stderr.reopen orig_stderr
+    [captured_stdout.read, captured_stderr.read]
+  ensure
+    $stdout.reopen orig_stdout
+    $stderr.reopen orig_stderr
 
-      orig_stdout.close
-      orig_stderr.close
-      captured_stdout.close!
-      captured_stderr.close!
-    end
+    orig_stdout.close
+    orig_stderr.close
+    captured_stdout.close!
+    captured_stderr.close!
   end
 
   ##
diff --git a/test/rubygems/test_gem_commands_update_command.rb b/test/rubygems/test_gem_commands_update_command.rb
index 324bd9c747..2683840f2e 100644
--- a/test/rubygems/test_gem_commands_update_command.rb
+++ b/test/rubygems/test_gem_commands_update_command.rb
@@ -79,7 +79,6 @@ class TestGemCommandsUpdateCommand < Gem::TestCase
     end
 
     out = @ui.output.split "\n"
-    assert_equal "Updating rubygems-update", out.shift
     assert_equal "Installing RubyGems 9", out.shift
     assert_equal "RubyGems system software updated", out.shift
 
@@ -123,7 +122,6 @@ class TestGemCommandsUpdateCommand < Gem::TestCase
     end
 
     out = @ui.output.split "\n"
-    assert_equal "Updating rubygems-update", out.shift
     assert_empty out
 
     err = @ui.error.split "\n"
@@ -132,6 +130,34 @@ class TestGemCommandsUpdateCommand < Gem::TestCase
     assert_empty err
   end
 
+  def test_execute_system_when_latest_does_not_support_your_ruby_but_previous_one_does
+    spec_fetcher do |fetcher|
+      fetcher.download "rubygems-update", 9 do |s|
+        s.files = %w[setup.rb]
+        s.required_ruby_version = "> 9"
+      end
+
+      fetcher.download "rubygems-update", 8 do |s|
+        s.files = %w[setup.rb]
+      end
+    end
+
+    @cmd.options[:args]          = []
+    @cmd.options[:system]        = true
+
+    use_ui @ui do
+      @cmd.execute
+    end
+
+    err = @ui.error.split "\n"
+    assert_empty err
+
+    out = @ui.output.split "\n"
+    assert_equal "Installing RubyGems 8", out.shift
+    assert_equal "RubyGems system software updated", out.shift
+    assert_empty out
+  end
+
   def test_execute_system_multiple
     spec_fetcher do |fetcher|
       fetcher.download "rubygems-update", 8 do |s|
@@ -151,7 +177,6 @@ class TestGemCommandsUpdateCommand < Gem::TestCase
     end
 
     out = @ui.output.split "\n"
-    assert_equal "Updating rubygems-update", out.shift
     assert_equal "Installing RubyGems 9", out.shift
     assert_equal "RubyGems system software updated", out.shift
 
@@ -185,7 +210,6 @@ class TestGemCommandsUpdateCommand < Gem::TestCase
     end
 
     out = @ui.output.split "\n"
-    assert_equal "Updating rubygems-update", out.shift
     assert_equal "Installing RubyGems 9", out.shift
     assert_equal "RubyGems system software updated", out.shift
 
@@ -242,7 +266,6 @@ class TestGemCommandsUpdateCommand < Gem::TestCase
     end
 
     out = @ui.output.split "\n"
-    assert_equal "Updating rubygems-update", out.shift
     assert_equal "Installing RubyGems 8", out.shift
     assert_equal "RubyGems system software updated", out.shift
 
@@ -353,7 +376,6 @@ class TestGemCommandsUpdateCommand < Gem::TestCase
     end
 
     out = @ui.output.split "\n"
-    assert_equal "Updating rubygems-update", out.shift
     assert_equal "Installing RubyGems 9", out.shift
     assert_equal "RubyGems system software updated", out.shift
 
diff --git a/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.lock b/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.lock
index 0937f71973..aa9587b231 100644
--- a/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.lock
+++ b/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.lock
@@ -152,18 +152,18 @@ dependencies = [
 
 [[package]]
 name = "rb-sys"
-version = "0.9.84"
+version = "0.9.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "3def04a96a36ef8681a2b2e26c01683b93a8630175c845fa06cab76c5a8c7ce0"
+checksum = "7285f2a7b92f58ab198e3fd59a71d2861478f9c4642f41e83582385818941697"
 dependencies = [
  "rb-sys-build",
 ]
 
 [[package]]
 name = "rb-sys-build"
-version = "0.9.84"
+version = "0.9.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c017d134afd764dd43c2faa91aa50b698a3bb4ff30e83113da483c789e74be8c"
+checksum = "71583945f94dabb6c0dfa63f1b71e929c1901e1e288ef3739ab8bed3b7069550"
 dependencies = [
  "bindgen",
  "lazy_static",
diff --git a/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.toml b/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.toml
index 6883495282..56a4188f15 100644
--- a/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.toml
+++ b/test/rubygems/test_gem_ext_cargo_builder/custom_name/ext/custom_name_lib/Cargo.toml
@@ -7,4 +7,4 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-rb-sys = "0.9.84"
+rb-sys = "0.9.86"
diff --git a/test/rubygems/test_gem_ext_cargo_builder/rust_ruby_example/Cargo.lock b/test/rubygems/test_gem_ext_cargo_builder/rust_ruby_example/Cargo.lock
index e65b28607d..8c394aec20 100644
--- a/test/rubygems/test_gem_ext_cargo_builder/rust_ruby_example/Cargo.lock
+++ b/test/rubygems/test_gem_ext_cargo_builder/rust_ruby_example/Cargo.lock
@@ -145,18 +145,18 @@ dependencies = [
 
 [[package]]
 name = "rb-sys"
-version = "0.9.83"
+version = "0.9.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "7e5b8d560b60790a3e60e56e73a8c7be88ac14e6af39fc82b5eca72c71753840"
+checksum = "7285f2a7b92f58ab198e3fd59a71d2861478f9c4642f41e83582385818941697"
 dependencies = [
  "rb-sys-build",
 ]
 
 [[package]]
 name = "rb-sys-build"
-version = "0.9.83"
+version = "0.9.86"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "c2d2bfd00002007d7e9ad93d0397437933040caf452d260c26dbef5fd95ae1a6"
+checksum = "71583945f94dabb6c0dfa63f1b71e929c1901e1e288ef3739ab8bed3b7069550"
 dependencies = [
  "bindgen",
  "lazy_static",
diff --git a/test/rubygems/test_gem_ext_cargo_builder/rust_ruby_example/Cargo.toml b/test/rubygems/test_gem_ext_cargo_builder/rust_ruby_example/Cargo.toml
index 26185e0e3c..39b2ae3919 100644
--- a/test/rubygems/test_gem_ext_cargo_builder/rust_ruby_example/Cargo.toml
+++ b/test/rubygems/test_gem_ext_cargo_builder/rust_ruby_example/Cargo.toml
@@ -7,4 +7,4 @@ edition = "2021"
 crate-type = ["cdylib"]
 
 [dependencies]
-rb-sys = "0.9.83"
+rb-sys = "0.9.86"
diff --git a/test/rubygems/test_require.rb b/test/rubygems/test_require.rb
index fc5f219490..30a4a477f9 100644
--- a/test/rubygems/test_require.rb
+++ b/test/rubygems/test_require.rb
@@ -489,6 +489,17 @@ class TestGemRequire < Gem::TestCase
     assert_equal %w[default-3.0], loaded_spec_names
   end
 
+  def test_normal_gem_does_not_shadow_default_gem
+    default_gem_spec = new_default_spec("foo", "2.0", nil, "foo.rb")
+    install_default_gems(default_gem_spec)
+
+    normal_gem_spec = util_spec("fake-foo", "3.0", nil, "lib/foo.rb")
+    install_specs(normal_gem_spec)
+
+    assert_require "foo"
+    assert_equal %w[foo-2.0], loaded_spec_names
+  end
+
   def test_normal_gems_with_overridden_load_error_message
     normal_gem_spec = util_spec("normal", "3.0", nil, "lib/normal/gem.rb")
 
@@ -529,6 +540,65 @@ class TestGemRequire < Gem::TestCase
     assert_equal %w[default-3.0.0.rc2], loaded_spec_names
   end
 
+  def test_default_gem_with_unresolved_gems_depending_on_it
+    my_http_old = util_spec "my-http", "0.1.1", nil, "lib/my/http.rb"
+    install_gem my_http_old
+
+    my_http_default = new_default_spec "my-http", "0.3.0", nil, "my/http.rb"
+    install_default_gems my_http_default
+
+    faraday_1 = util_spec "faraday", "1", { "my-http" => ">= 0" }
+    install_gem faraday_1
+
+    faraday_2 = util_spec "faraday", "2", { "my-http" => ">= 0" }
+    install_gem faraday_2
+
+    chef = util_spec "chef", "1", { "faraday" => [">= 1", "< 3"] }, "lib/chef.rb"
+    install_gem chef
+
+    assert_require "chef"
+    assert_require "my/http"
+  end
+
+  def test_default_gem_required_circulary_with_unresolved_gems_depending_on_it
+    my_http_old = util_spec "my-http", "0.1.1", nil, "lib/my/http.rb"
+    install_gem my_http_old
+
+    my_http_default = new_default_spec "my-http", "0.3.0", nil, "my/http.rb"
+    my_http_default_path = File.join(@tempdir, "default_gems", "lib", "my/http.rb")
+    install_default_gems my_http_default
+    File.write(my_http_default_path, 'require "my/http"')
+
+    faraday_1 = util_spec "faraday", "1", { "my-http" => ">= 0" }
+    install_gem faraday_1
+
+    faraday_2 = util_spec "faraday", "2", { "my-http" => ">= 0" }
+    install_gem faraday_2
+
+    chef = util_spec "chef", "1", { "faraday" => [">= 1", "< 3"] }, "lib/chef.rb"
+    install_gem chef
+
+    assert_require "chef"
+
+    out, err = capture_output do
+      assert_require "my/http"
+    end
+
+    assert_empty out
+
+    circular_require_warning = false
+
+    err_lines = err.split("\n").reject do |line|
+      if line.include?("circular require")
+        circular_require_warning = true
+      elsif circular_require_warning # ignore backtrace lines for circular require warning
+        circular_require_warning = line.start_with?(/[\s]/)
+      end
+    end
+
+    assert_empty err_lines
+  end
+
   def loaded_spec_names
     Gem.loaded_specs.values.map(&:full_name).sort
   end
diff --git a/tool/bundler/dev_gems.rb b/tool/bundler/dev_gems.rb
index 5e5ba94ec2..cb4b556d2f 100644
--- a/tool/bundler/dev_gems.rb
+++ b/tool/bundler/dev_gems.rb
@@ -13,7 +13,7 @@ gem "parallel", "~> 1.19"
 gem "rspec-core", "~> 3.12"
 gem "rspec-expectations", "~> 3.12"
 gem "rspec-mocks", "~> 3.12"
-gem "uri", "~> 0.12.0"
+gem "uri", "~> 0.13.0"
 
 group :doc do
   gem "nronn", "~> 0.11.1", platform: :ruby
diff --git a/tool/bundler/test_gems.rb b/tool/bundler/test_gems.rb
index aa1cfd09a5..32cb6b34ee 100644
--- a/tool/bundler/test_gems.rb
+++ b/tool/bundler/test_gems.rb
@@ -3,6 +3,7 @@
 source "https://rubygems.org"
 
 gem "rack", "~> 2.0"
+gem "base64"
 gem "webrick", "1.7.0"
 gem "rack-test", "~> 1.1"
 gem "compact_index", "~> 0.15.0"