Add test for String#rstrip!

* test/ruby/test_string.rb (TestString#test_rstrip_bang): Add test
  for String#rstrip!.  [Fix GH-1176]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53354 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

ChangeLog

@@ -1,3 +1,8 @@
+Mon Dec 28 14:55:57 2015  Kuniaki IGARASHI  <igaiga@gmail.com>
+
+	* test/ruby/test_string.rb (TestString#test_rstrip_bang): Add test
+	  for String#rstrip!.  [Fix GH-1176]
+
 Mon Dec 28 09:18:53 2015  Kuniaki IGARASHI  <igaiga@gmail.com>
 
 	* test/ruby/test_string.rb (TestString#test_lstrip_bang): Add test

test/ruby/test_string.rb

@@ -2142,6 +2142,22 @@ class TestString < Test::Unit::TestCase
     assert_raise(Encoding::CompatibilityError) { "\u3042".encode("ISO-2022-JP").rstrip }
   end
 
+  def test_rstrip_bang
+    s1 = S("  hello  ")
+    assert_equal("  hello", s1.rstrip!)
+    assert_equal("  hello", s1)
+
+    s2 = S("\u3042  ")
+    assert_equal("\u3042", s2.rstrip!)
+    assert_equal("\u3042", s2)
+
+    s3 = S("  \u3042")
+    assert_equal(nil, s3.rstrip!)
+    assert_equal("  \u3042", s3)
+
+    assert_raise(Encoding::CompatibilityError) { "\u3042".encode("ISO-2022-JP").rstrip! }
+  end
+
   def test_lstrip
     assert_equal("hello  ", "  hello  ".lstrip)
     assert_equal("\u3042", "   \u3042".lstrip)