1 files changed, 13 insertions, 1 deletions
diff --git a/spec/ruby/core/matchdata/string_spec.rb b/spec/ruby/core/matchdata/string_spec.rb
index ff1b4eab5b..952e953318 100644
--- a/spec/ruby/core/matchdata/string_spec.rb
+++ b/spec/ruby/core/matchdata/string_spec.rb
@@ -9,6 +9,18 @@ describe "MatchData#string" do
   it "returns a frozen copy of the match string" do
     str = /(.)(.)(\d+)(\d)/.match("THX1138.").string
     str.should == "THX1138."
-    str.frozen?.should == true
+    str.should.frozen?
+  end
+
+  it "returns the same frozen string for every call" do
+    md = /(.)(.)(\d+)(\d)/.match("THX1138.")
+    md.string.should equal(md.string)
+  end
+
+  it "returns a frozen copy of the matched string for gsub!(String)" do
+    s = +'he[[o'
+    s.gsub!('[', ']')
+    $~.string.should == 'he[[o'
+    $~.string.should.frozen?
   end
 end