Merge bundler to standard libraries.

  rubygems 2.7.x depends bundler-1.15.x. This is preparation for
  rubygems and bundler migration.

  * lib/bundler.rb, lib/bundler/*: files of bundler-1.15.4
  * spec/bundler/*: rspec examples of bundler-1.15.4. I applied patches.
    * https://github.com/bundler/bundler/pull/6007
    * Exclude not working examples on ruby repository.
    * Fake ruby interpriter instead of installed ruby.
  * Makefile.in: Added test task named `test-bundler`. This task is only
    working macOS/linux yet. I'm going to support Windows environment later.
  * tool/sync_default_gems.rb: Added sync task for bundler.

  [Feature #12733][ruby-core:77172]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59779 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 27 insertions, 0 deletions

diff --git a/lib/bundler/psyched_yaml.rb b/lib/bundler/psyched_yaml.rb
new file mode 100644
index 0000000000..69d2ae78c5
--- /dev/null
+++ b/lib/bundler/psyched_yaml.rb
@@ -0,0 +1,27 @@
+# frozen_string_literal: true
+# Psych could be a gem, so try to ask for it
+begin
+  gem "psych"
+rescue LoadError
+end if defined?(gem)
+
+# Psych could be in the stdlib
+# but it's too late if Syck is already loaded
+begin
+  require "psych" unless defined?(Syck)
+rescue LoadError
+  # Apparently Psych wasn't available. Oh well.
+end
+
+# At least load the YAML stdlib, whatever that may be
+require "yaml" unless defined?(YAML.dump)
+
+module Bundler
+  # On encountering invalid YAML,
+  # Psych raises Psych::SyntaxError
+  if defined?(::Psych::SyntaxError)
+    YamlLibrarySyntaxError = ::Psych::SyntaxError
+  else # Syck raises ArgumentError
+    YamlLibrarySyntaxError = ::ArgumentError
+  end
+end