1 files changed, 65 insertions, 16 deletions

diff --git a/lib/bundler/installer/standalone.rb b/lib/bundler/installer/standalone.rb
index f16135cb48..5331df2e95 100644
--- a/lib/bundler/installer/standalone.rb
+++ b/lib/bundler/installer/standalone.rb
@@ -12,12 +12,15 @@ module Bundler
       end
       File.open File.join(bundler_path, "setup.rb"), "w" do |file|
         file.puts "require 'rbconfig'"
-        file.puts "ruby_engine = RUBY_ENGINE"
-        file.puts "ruby_version = RbConfig::CONFIG[\"ruby_version\"]"
-        file.puts "path = File.expand_path('..', __FILE__)"
+        file.puts prevent_gem_activation
+        file.puts define_path_helpers
         file.puts reverse_rubygems_kernel_mixin
         paths.each do |path|
-          file.puts %($:.unshift File.expand_path("\#{path}/#{path}"))
+          if Pathname.new(path).absolute?
+            file.puts %($:.unshift "#{path}")
+          else
+            file.puts %($:.unshift File.expand_path("\#{__dir__}/#{path}"))
+          end
         end
       end
     end
@@ -28,37 +31,83 @@ 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}/#{ruby_version}')
+          gem_path(path, spec).
+            sub(version_dir, '#{RUBY_ENGINE}/#{Gem.ruby_api_version}').
+            sub(extensions_dir, 'extensions/\k<platform>/#{Gem.extension_api_version}')
           # This is a static string intentionally. It's interpolated at a later time.
         end
-      end.flatten
+      end.flatten.compact
     end
 
     def version_dir
-      "#{Bundler::RubyVersion.system.engine}/#{RbConfig::CONFIG["ruby_version"]}"
+      "#{RUBY_ENGINE}/#{Gem.ruby_api_version}"
+    end
+
+    def extensions_dir
+      %r{extensions/(?<platform>[^/]+)/#{Regexp.escape(Gem.extension_api_version)}}
     end
 
     def bundler_path
-      Bundler.root.join(Bundler.settings[:path], "bundler")
+      Bundler.root.join(Bundler.settings[:path].to_s, "bundler")
     end
 
     def gem_path(path, spec)
       full_path = Pathname.new(path).absolute? ? path : File.join(spec.full_gem_path, path)
-      Pathname.new(full_path).relative_path_from(Bundler.root.join(bundler_path)).to_s
+      if spec.source.instance_of?(Source::Path) && spec.source.path.absolute?
+        full_path
+      else
+        SharedHelpers.relative_path_to(full_path, from: Bundler.root.join(bundler_path))
+      end
     rescue TypeError
       error_message = "#{spec.name} #{spec.version} has an invalid gemspec"
       raise Gem::InvalidSpecificationException.new(error_message)
     end
 
+    def prevent_gem_activation
+      <<~'END'
+        module Kernel
+          remove_method(:gem) if private_method_defined?(:gem)
+
+          def gem(*)
+          end
+
+          private :gem
+        end
+      END
+    end
+
+    def define_path_helpers
+      <<~'END'
+        unless defined?(Gem)
+          module Gem
+            def self.ruby_api_version
+              RbConfig::CONFIG["ruby_version"]
+            end
+
+            def self.extension_api_version
+              if 'no' == RbConfig::CONFIG['ENABLE_SHARED']
+                "#{ruby_api_version}-static"
+              else
+                ruby_api_version
+              end
+            end
+          end
+        end
+      END
+    end
+
     def reverse_rubygems_kernel_mixin
       <<~END
-      kernel = (class << ::Kernel; self; end)
-      [kernel, ::Kernel].each do |k|
-        if k.private_method_defined?(:gem_original_require)
-          private_require = k.private_method_defined?(:require)
-          k.send(:remove_method, :require)
-          k.send(:define_method, :require, k.instance_method(:gem_original_require))
-          k.send(:private, :require) if private_require
+      if Gem.respond_to?(:discover_gems_on_require=)
+        Gem.discover_gems_on_require = false
+      else
+        [::Kernel.singleton_class, ::Kernel].each do |k|
+          if k.private_method_defined?(:gem_original_require)
+            private_require = k.private_method_defined?(:require)
+            k.send(:remove_method, :require)
+            k.send(:define_method, :require, k.instance_method(:gem_original_require))
+            k.send(:private, :require) if private_require
+          end
         end
       end
       END