[rubygems/rubygems] Fix extension paths in generated standalone script

The paths for extensions of gems would contain the hardcoded ruby
version on which the extension was built. This will replace it with
runtime ruby version like the parent version directory. It will make the
standalone script compatible between different ruby version installations.

a9dae93d5d

lib/bundler/installer/standalone.rb

@@ -29,7 +29,9 @@ module Bundler
       @specs.map do |spec|
         next if spec.name == "bundler"
         Array(spec.require_paths).map do |path|
-          gem_path(path, spec).sub(version_dir, '#{RUBY_ENGINE}/#{RbConfig::CONFIG["ruby_version"]}')
+          gem_path(path, spec).
+            sub(version_dir, '#{RUBY_ENGINE}/#{RbConfig::CONFIG["ruby_version"]}').
+            sub(extensions_dir, 'extensions/\k<platform>/#{RbConfig::CONFIG["ruby_version"]}')
           # This is a static string intentionally. It's interpolated at a later time.
         end
       end.flatten.compact
@@ -39,6 +41,10 @@ module Bundler
       "#{RUBY_ENGINE}/#{RbConfig::CONFIG["ruby_version"]}"
     end
 
+    def extensions_dir
+      %r{extensions/(?<platform>[^/]+)/#{RbConfig::CONFIG["ruby_version"]}}
+    end
+
     def bundler_path
       Bundler.root.join(Bundler.settings[:path], "bundler")
     end

spec/bundler/install/gems/standalone_spec.rb

@@ -202,8 +202,9 @@ RSpec.shared_examples "bundle install --standalone" do
     it "generates a bundle/bundler/setup.rb with the proper paths" do
       expected_path = bundled_app("bundle/bundler/setup.rb")
       extension_line = File.read(expected_path).each_line.find {|line| line.include? "/extensions/" }.strip
+      platform = Gem::Platform.local
       expect(extension_line).to start_with '$:.unshift File.expand_path("#{__dir__}/../#{RUBY_ENGINE}/#{RbConfig::CONFIG["ruby_version"]}/extensions/'
-      expect(extension_line).to end_with '/very_simple_binary-1.0")'
+      expect(extension_line).to end_with platform.to_s + '/#{RbConfig::CONFIG["ruby_version"]}/very_simple_binary-1.0")'
     end
   end