Ruby 1.9 version style

Library/Homebrew/pathname+yeast.rb

@@ -104,7 +104,8 @@ class Pathname
     return $1.gsub('_', '.') if $1
 
     # eg. foobar-4.5.1-1
-    /-((\d+\.)*\d+-\d+)$/.match stem
+    # eg. ruby-1.9.1-p243
+    /-((\d+\.)*\d\.\d+-p?\d+)$/.match stem
     return $1 if $1
 
     # eg. foobar-4.5.1

Library/Homebrew/unittest.rb

@@ -318,4 +318,9 @@ class BeerTasting <Test::Unit::TestCase
     d.mkpath
     assert_equal '0.1.9', d.version
   end
+  
+  def test_ruby_version_style
+    f=MockFormula.new 'ftp://ftp.ruby-lang.org/pub/ruby/1.9/ruby-1.9.1-p243.tar.gz'
+    assert_equal '1.9.1-p243', f.version
+  end
 end