string.c: term fill

* string.c (rb_str_chop_bang): fill wchar terminator.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@48761 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

string.c

@@ -7024,7 +7024,7 @@ rb_str_chop_bang(VALUE str)
 	long len;
 	len = chopped_length(str);
 	STR_SET_LEN(str, len);
-	RSTRING_PTR(str)[len] = '\0';
+	TERM_FILL(&RSTRING_PTR(str)[len], TERM_LEN(str));
 	if (ENC_CODERANGE(str) != ENC_CODERANGE_7BIT) {
 	    ENC_CODERANGE_CLEAR(str);
 	}

test/-ext-/string/test_cstr.rb

@@ -52,6 +52,10 @@ class Test_StringCStr < Test::Unit::TestCase
     assert_wchars_term_char("a\n") {|s| s.chop!}
   end
 
+  def test_wchar_chomp!
+    assert_wchars_term_char("a\n") {|s| s.chomp!}
+  end
+
   def assert_wchars_term_char(str)
     result = {}
     WCHARS.map do |enc|