Merge rubygems master.

  This is RC version of Rubygems 2.7.0.
  https://github.com/rubygems/rubygems/commit/688fb7e83c13c3fe7c2bb03c49a2db4c82852aee

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@60133 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 112 insertions, 0 deletions

diff --git a/lib/rubygems/bundler_version_finder.rb b/lib/rubygems/bundler_version_finder.rb
new file mode 100644
index 0000000000..baca170840
--- /dev/null
+++ b/lib/rubygems/bundler_version_finder.rb
@@ -0,0 +1,112 @@
+module Gem::BundlerVersionFinder
+  @without_filtering = false
+
+  def self.without_filtering
+    without_filtering, @without_filtering = true, @without_filtering
+    yield
+  ensure
+    @without_filtering = without_filtering
+  end
+
+  def self.bundler_version
+    version, _ = bundler_version_with_reason
+
+    return unless version
+
+    Gem::Version.new(version)
+  end
+
+  def self.bundler_version_with_reason
+    return if @without_filtering
+
+    if v = ENV["BUNDLER_VERSION"]
+      return [v, "`$BUNDLER_VERSION`"]
+    end
+    if v = bundle_update_bundler_version
+      return if v == true
+      return [v, "`bundle update --bundler`"]
+    end
+    v, lockfile = lockfile_version
+    if v
+      return [v, "your #{lockfile}"]
+    end
+  end
+
+  def self.missing_version_message
+    return unless vr = bundler_version_with_reason
+    <<-EOS
+Could not find 'bundler' (#{vr.first}) required by #{vr.last}.
+To update to the lastest version installed on your system, run `bundle update --bundler`.
+To install the missing version, run `gem install bundler:#{vr.first}`
+    EOS
+  end
+
+  def self.compatible?(spec)
+    return true unless spec.name == "bundler".freeze
+    return true unless bundler_version = self.bundler_version
+    if bundler_version.segments.first >= 2
+      spec.version == bundler_version
+    else # 1.x
+      spec.version.segments.first < 2
+    end
+  end
+
+  def self.filter!(specs)
+    return unless bundler_version = self.bundler_version
+    if bundler_version.segments.first >= 2
+      specs.reject! { |spec| spec.version != bundler_version }
+    else # 1.x
+      specs.reject! { |spec| spec.version.segments.first >= 2}
+    end
+  end
+
+  def self.bundle_update_bundler_version
+    return unless File.basename($0) == "bundle".freeze
+    return unless "update".start_with?(ARGV.first || " ")
+    bundler_version = nil
+    update_index = nil
+    ARGV.each_with_index do |a, i|
+      if update_index && update_index.succ == i && a =~ Gem::Version::ANCHORED_VERSION_PATTERN
+        bundler_version = a
+      end
+      next unless a =~ /\A--bundler(?:[= ](#{Gem::Version::VERSION_PATTERN}))?\z/
+      bundler_version = $1 || true
+      update_index = i
+    end
+    bundler_version
+  end
+  private_class_method :bundle_update_bundler_version
+
+  def self.lockfile_version
+    return unless lockfile = lockfile_contents
+    lockfile, contents = lockfile
+    lockfile ||= "lockfile"
+    regexp = /\n\nBUNDLED WITH\n\s{2,}(#{Gem::Version::VERSION_PATTERN})\n/
+    return unless contents =~ regexp
+    [$1, lockfile]
+  end
+  private_class_method :lockfile_version
+
+  def self.lockfile_contents
+    gemfile = ENV["BUNDLE_GEMFILE"]
+    gemfile = nil if gemfile && gemfile.empty?
+    Gem::Util.traverse_parents Dir.pwd do |directory|
+      next unless gemfile = Gem::GEM_DEP_FILES.find { |f| File.file?(f.untaint) }
+
+      gemfile = File.join directory, gemfile
+      break
+    end unless gemfile
+
+    return unless gemfile
+
+    lockfile = case gemfile
+    when "gems.rb" then "gems.locked"
+    else "#{gemfile}.lock"
+    end.untaint
+
+    return unless File.file?(lockfile)
+
+    [lockfile, File.read(lockfile)]
+  end
+  private_class_method :lockfile_contents
+end