From cd453f16b42ea9b68993631b27773165b24ee9b2 Mon Sep 17 00:00:00 2001
From: glass <glass@b2dd03c8-39d4-4d8f-98ff-823fe69b080e>
Date: Thu, 27 Dec 2012 11:43:02 +0000
Subject: [PATCH] * ext/stringio/stringio.c (strio_ungetc): raise IOError
 instead of RuntimeError   if the string is frozen.   [Bug #7231]
 [ruby-core:48530]

* ext/stringio/stringio.c (strio_ungetbyte): ditto.

* test/stringio/test_stringio.rb: a test for above.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@38628 b2dd03c8-39d4-4d8f-98ff-823fe69b080e
---
 ChangeLog                      | 10 ++++++++++
 ext/stringio/stringio.c        |  2 ++
 test/stringio/test_stringio.rb |  8 ++++++++
 3 files changed, 20 insertions(+)

diff --git a/ChangeLog b/ChangeLog
index cbabf013c4..c26c6cf8b2 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,13 @@
+Thu Dec 27 20:11:29 2012  Masaki Matsushita  <glass.saga@gmail.com>
+
+	* ext/stringio/stringio.c (strio_ungetc): raise IOError instead of RuntimeError
+	  if the string is frozen.
+	  [Bug #7231] [ruby-core:48530]
+
+	* ext/stringio/stringio.c (strio_ungetbyte): ditto.
+
+	* test/stringio/test_stringio.rb: a test for above.
+
 Wed Dec 26 23:55:18 2012  Keiju Ishitsuka  <keiju@ishitsuka.com>
 
 	* lib/irb/context.rb: fix IRB::Inspector#keys_with_inspector [Bug #7598]
diff --git a/ext/stringio/stringio.c b/ext/stringio/stringio.c
index d763854faf..501c7ddddf 100644
--- a/ext/stringio/stringio.c
+++ b/ext/stringio/stringio.c
@@ -737,6 +737,7 @@ strio_ungetc(VALUE self, VALUE c)
     rb_encoding *enc, *enc2;
 
     if (NIL_P(c)) return Qnil;
+    check_modifiable(ptr);
     if (FIXNUM_P(c)) {
 	int cc = FIX2INT(c);
 	char buf[16];
@@ -801,6 +802,7 @@ strio_ungetbyte(VALUE self, VALUE c)
 	cl = RSTRING_LEN(c);
 	if (cl == 0) return Qnil;
     }
+    check_modifiable(ptr);
     rb_str_modify(str);
     if (cl > pos) {
 	char *s;
diff --git a/test/stringio/test_stringio.rb b/test/stringio/test_stringio.rb
index 417a53b383..0ea3e4f961 100644
--- a/test/stringio/test_stringio.rb
+++ b/test/stringio/test_stringio.rb
@@ -504,6 +504,14 @@ class TestStringIO < Test::Unit::TestCase
     assert_raise(RuntimeError, bug) {s.reopen("")}
   end
 
+  def test_frozen_string
+    s = StringIO.new("".freeze)
+    bug = '[ruby-core:48530]'
+    assert_raise(IOError, bug) {s.write("foo")}
+    assert_raise(IOError, bug) {s.ungetc("a")}
+    assert_raise(IOError, bug) {s.ungetbyte("a")}
+  end
+
   def test_readlines_limit_0
     assert_raise(ArgumentError, "[ruby-dev:43392]") { StringIO.new.readlines(0) }
   end