Additional fix and tests for r53851

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@53854 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

string.c

@@ -1383,6 +1383,7 @@ rb_str_init(int argc, VALUE *argv, VALUE str)
 	vcapa = kwargs[1];
 	if (vcapa != Qundef && !NIL_P(vcapa)) {
 	    long capa = NUM2LONG(vcapa);
+	    str_discard(str);
 	    if (capa < STR_BUF_MIN_SIZE) {
 		capa = STR_BUF_MIN_SIZE;
 	    }
@@ -1405,6 +1406,7 @@ rb_str_init(int argc, VALUE *argv, VALUE str)
 	}
 	else if (n == 1) {
 	    StringValue(orig);
+	    str_discard(str);
 	    str_replace(str, orig);
 	}
 	if (enc != Qundef && !NIL_P(enc)) {
@@ -1414,9 +1416,7 @@ rb_str_init(int argc, VALUE *argv, VALUE str)
     }
     else if (n == 1) {
 	StringValue(orig);
-	if (OBJ_FROZEN(str)) {
-	    rb_error_frozen_object(str);
-	}
+	str_discard(str);
 	str_replace(str, orig);
     }
     return str;

test/ruby/test_string.rb

@@ -59,6 +59,17 @@ class TestString < Test::Unit::TestCase
     assert_equal(Encoding::EUC_JP, S("", capacity: 1000, encoding: "euc-jp").encoding)
   end
 
+  def test_initialize
+    str = S("").freeze
+    assert_equal("", str.__send__(:initialize))
+    assert_raise(RuntimeError){ str.__send__(:initialize, 'abc') }
+    assert_raise(RuntimeError){ str.__send__(:initialize, capacity: 1000) }
+    assert_raise(RuntimeError){ str.__send__(:initialize, 'abc', capacity: 1000) }
+    assert_raise(RuntimeError){ str.__send__(:initialize, encoding: 'euc-jp') }
+    assert_raise(RuntimeError){ str.__send__(:initialize, 'abc', encoding: 'euc-jp') }
+    assert_raise(RuntimeError){ str.__send__(:initialize, 'abc', capacity: 1000, encoding: 'euc-jp') }
+  end
+
   def test_AREF # '[]'
     assert_equal("A",  S("AooBar")[0])
     assert_equal("B",  S("FooBaB")[-1])