common.mk: extract-gems

* common.mk (extract-gems): extract gem files to install them even
  if zlib is not available.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@49271 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 16 insertions, 0 deletions

diff --git a/tool/gem-unpack.rb b/tool/gem-unpack.rb
new file mode 100755
index 0000000000..5f15751d9c
--- /dev/null
+++ b/tool/gem-unpack.rb
@@ -0,0 +1,16 @@
+require 'rubygems'
+require 'rubygems/package'
+
+def Gem.unpack(file, dir = nil)
+  pkg = Gem::Package.new(file)
+  pkg.security_policy = Gem::Security::LowSecurity
+  spec = pkg.spec
+  target = spec.full_name
+  target = File.join(dir, target) if dir
+  pkg.extract_files target
+  spec_file = File.join(target, "#{spec.name}.gemspec")
+  open(spec_file, 'wb') do |f|
+    f.print spec.to_ruby
+  end
+  puts "Unpacked #{file}"
+end