error.c: check argument of Warning.warn

* error.c (rb_warning_s_warn): the argument must be an
  ASCII-compatible string.  [ruby-core:77430] [Bug #12793]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@56274 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

3 files changed, 19 insertions, 0 deletions

diff --git a/ChangeLog b/ChangeLog
index 111c69bc95..eb85509f84 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+Wed Sep 28 00:21:00 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
+
+	* error.c (rb_warning_s_warn): the argument must be an
+	  ASCII-compatible string.  [ruby-core:77430] [Bug #12793]
+
 Tue Sep 27 23:22:31 2016  Nobuyoshi Nakada  <nobu@ruby-lang.org>
 
 	* parse.y (symbol, dsym, parser_set_number_literal): set state to
diff --git a/error.c b/error.c
index 2fcacfaa5b..4758961e93 100644
--- a/error.c
+++ b/error.c
@@ -152,6 +152,8 @@ ruby_only_for_internal_use(const char *func)
 static VALUE
 rb_warning_s_warn(VALUE mod, VALUE str)
 {
+    Check_Type(str, T_STRING);
+    rb_must_asciicompat(str);
     rb_write_error_str(str);
     return Qnil;
 }
diff --git a/test/ruby/test_exception.rb b/test/ruby/test_exception.rb
index 3735e492d8..91d3ac1e93 100644
--- a/test/ruby/test_exception.rb
+++ b/test/ruby/test_exception.rb
@@ -940,4 +940,16 @@ $stderr = $stdout; raise "\x82\xa0"') do |outs, errs, status|
       remove_method :warn2
     end
   end
+
+  def test_warning_warn_invalid_argument
+    assert_raise(TypeError) do
+      ::Warning.warn nil
+    end
+    assert_raise(TypeError) do
+      ::Warning.warn 1
+    end
+    assert_raise(Encoding::CompatibilityError) do
+      ::Warning.warn "\x00a\x00b\x00c".force_encoding("utf-16be")
+    end
+  end
 end