JRUBY-6141 - added RubySpec test.

Signed-off-by: Hiro Asari <asari.ruby@gmail.com>

spec/regression/JRUBY-6141_matchdata_captures_spec.rb

@@ -0,0 +1,17 @@
+describe "JRUBY-6141: Matchdata#captures" do
+
+  before :all do
+    "first, last".scan(Regexp.new('(first|last)')) do
+      @firstmatch ||= Regexp.last_match
+    end
+    @lastmatch = Regexp.last_match
+  end
+
+  it "returns first value from Regexp.last_match after all String#scan iterations" do
+    @firstmatch.captures[0].should == "first"
+  end
+
+  it "returns last value from Regexp.last_match after all String#scan iterations" do
+    @lastmatch.captures[0].should == "last"
+  end
+end