diff -r 81b2a30da853 Lib/test/test_sax.py
--- a/Lib/test/test_sax.py	Sun Jan 20 16:35:09 2013 +0200
+++ b/Lib/test/test_sax.py	Sun Jan 20 17:24:13 2013 +0200
@@ -13,7 +13,7 @@
 from xml.sax.expatreader import create_parser
 from xml.sax.handler import feature_namespaces
 from xml.sax.xmlreader import InputSource, AttributesImpl, AttributesNSImpl
-from io import StringIO
+from io import BytesIO, StringIO
 from test.support import findfile, run_unittest
 import unittest
 
@@ -158,31 +158,29 @@
 
 # ===== XMLGenerator
 
-start = '<?xml version="1.0" encoding="iso-8859-1"?>\n'
-
-class XmlgenTest(unittest.TestCase):
+class XmlgenTest:
     def test_xmlgen_basic(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result)
         gen.startDocument()
         gen.startElement("doc", {})
         gen.endElement("doc")
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start + "<doc></doc>")
+        self.assertEqual(result.getvalue(), self.xml("<doc></doc>"))
 
     def test_xmlgen_basic_empty(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result, short_empty_elements=True)
         gen.startDocument()
         gen.startElement("doc", {})
         gen.endElement("doc")
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start + "<doc/>")
+        self.assertEqual(result.getvalue(), self.xml("<doc/>"))
 
     def test_xmlgen_content(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result)
 
         gen.startDocument()
@@ -191,10 +189,10 @@
         gen.endElement("doc")
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start + "<doc>huhei</doc>")
+        self.assertEqual(result.getvalue(), self.xml("<doc>huhei</doc>"))
 
     def test_xmlgen_content_empty(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result, short_empty_elements=True)
 
         gen.startDocument()
@@ -203,10 +201,10 @@
         gen.endElement("doc")
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start + "<doc>huhei</doc>")
+        self.assertEqual(result.getvalue(), self.xml("<doc>huhei</doc>"))
 
     def test_xmlgen_pi(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result)
 
         gen.startDocument()
@@ -215,10 +213,11 @@
         gen.endElement("doc")
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start + "<?test data?><doc></doc>")
+        self.assertEqual(result.getvalue(),
+            self.xml("<?test data?><doc></doc>"))
 
     def test_xmlgen_content_escape(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result)
 
         gen.startDocument()
@@ -228,10 +227,10 @@
         gen.endDocument()
 
         self.assertEqual(result.getvalue(),
-            start + "<doc>&lt;huhei&amp;</doc>")
+            self.xml("<doc>&lt;huhei&amp;</doc>"))
 
     def test_xmlgen_attr_escape(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result)
 
         gen.startDocument()
@@ -245,13 +244,43 @@
         gen.endElement("doc")
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start +
-            ("<doc a='\"'><e a=\"'\"></e>"
-             "<e a=\"'&quot;\"></e>"
-             "<e a=\"&#10;&#13;&#9;\"></e></doc>"))
+        self.assertEqual(result.getvalue(), self.xml(
+            "<doc a='\"'><e a=\"'\"></e>"
+            "<e a=\"'&quot;\"></e>"
+            "<e a=\"&#10;&#13;&#9;\"></e></doc>"))
+
+    def test_xmlgen_encoding(self):
+        encodings = ('iso-8859-15', 'utf-8', 'utf-8-sig',
+                     'utf-16', 'utf-16be', 'utf-16le',
+                     'utf-32', 'utf-32be', 'utf-32le')
+        for encoding in encodings:
+            result = self.ioclass()
+            gen = XMLGenerator(result, encoding=encoding)
+
+            gen.startDocument()
+            gen.startElement("doc", {"a": '\u20ac'})
+            gen.characters("\u20ac")
+            gen.endElement("doc")
+            gen.endDocument()
+
+            self.assertEqual(result.getvalue(),
+                self.xml('<doc a="\u20ac">\u20ac</doc>', encoding=encoding))
+
+    def test_xmlgen_unencodable(self):
+        result = self.ioclass()
+        gen = XMLGenerator(result, encoding='ascii')
+
+        gen.startDocument()
+        gen.startElement("doc", {"a": '\u20ac'})
+        gen.characters("\u20ac")
+        gen.endElement("doc")
+        gen.endDocument()
+
+        self.assertEqual(result.getvalue(),
+            self.xml('<doc a="&#8364;">&#8364;</doc>', encoding='ascii'))
 
     def test_xmlgen_ignorable(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result)
 
         gen.startDocument()
@@ -260,10 +289,10 @@
         gen.endElement("doc")
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start + "<doc> </doc>")
+        self.assertEqual(result.getvalue(), self.xml("<doc> </doc>"))
 
     def test_xmlgen_ignorable_empty(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result, short_empty_elements=True)
 
         gen.startDocument()
@@ -272,10 +301,10 @@
         gen.endElement("doc")
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start + "<doc> </doc>")
+        self.assertEqual(result.getvalue(), self.xml("<doc> </doc>"))
 
     def test_xmlgen_ns(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result)
 
         gen.startDocument()
@@ -288,12 +317,12 @@
         gen.endPrefixMapping("ns1")
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start + \
-           ('<ns1:doc xmlns:ns1="%s"><udoc></udoc></ns1:doc>' %
+        self.assertEqual(result.getvalue(), self.xml(
+           '<ns1:doc xmlns:ns1="%s"><udoc></udoc></ns1:doc>' %
                                          ns_uri))
 
     def test_xmlgen_ns_empty(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result, short_empty_elements=True)
 
         gen.startDocument()
@@ -306,12 +335,12 @@
         gen.endPrefixMapping("ns1")
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start + \
-           ('<ns1:doc xmlns:ns1="%s"><udoc/></ns1:doc>' %
+        self.assertEqual(result.getvalue(), self.xml(
+           '<ns1:doc xmlns:ns1="%s"><udoc/></ns1:doc>' %
                                          ns_uri))
 
     def test_1463026_1(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result)
 
         gen.startDocument()
@@ -319,10 +348,10 @@
         gen.endElementNS((None, 'a'), 'a')
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start+'<a b="c"></a>')
+        self.assertEqual(result.getvalue(), self.xml('<a b="c"></a>'))
 
     def test_1463026_1_empty(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result, short_empty_elements=True)
 
         gen.startDocument()
@@ -330,10 +359,10 @@
         gen.endElementNS((None, 'a'), 'a')
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start+'<a b="c"/>')
+        self.assertEqual(result.getvalue(), self.xml('<a b="c"/>'))
 
     def test_1463026_2(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result)
 
         gen.startDocument()
@@ -343,10 +372,10 @@
         gen.endPrefixMapping(None)
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start+'<a xmlns="qux"></a>')
+        self.assertEqual(result.getvalue(), self.xml('<a xmlns="qux"></a>'))
 
     def test_1463026_2_empty(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result, short_empty_elements=True)
 
         gen.startDocument()
@@ -356,10 +385,10 @@
         gen.endPrefixMapping(None)
         gen.endDocument()
 
-        self.assertEqual(result.getvalue(), start+'<a xmlns="qux"/>')
+        self.assertEqual(result.getvalue(), self.xml('<a xmlns="qux"/>'))
 
     def test_1463026_3(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result)
 
         gen.startDocument()
@@ -370,10 +399,10 @@
         gen.endDocument()
 
         self.assertEqual(result.getvalue(),
-            start+'<my:a xmlns:my="qux" b="c"></my:a>')
+            self.xml('<my:a xmlns:my="qux" b="c"></my:a>'))
 
     def test_1463026_3_empty(self):
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result, short_empty_elements=True)
 
         gen.startDocument()
@@ -384,7 +413,7 @@
         gen.endDocument()
 
         self.assertEqual(result.getvalue(),
-            start+'<my:a xmlns:my="qux" b="c"/>')
+            self.xml('<my:a xmlns:my="qux" b="c"/>'))
 
     def test_5027_1(self):
         # The xml prefix (as in xml:lang below) is reserved and bound by
@@ -401,13 +430,13 @@
 
         parser = make_parser()
         parser.setFeature(feature_namespaces, True)
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result)
         parser.setContentHandler(gen)
         parser.parse(test_xml)
 
         self.assertEqual(result.getvalue(),
-                         start + (
+                         self.xml(
                          '<a:g1 xmlns:a="http://example.com/ns">'
                           '<a:g2 xml:lang="en">Hello</a:g2>'
                          '</a:g1>'))
@@ -420,7 +449,7 @@
         #
         # This test demonstrates the bug by direct manipulation of the
         # XMLGenerator.
-        result = StringIO()
+        result = self.ioclass()
         gen = XMLGenerator(result)
 
         gen.startDocument()
@@ -435,15 +464,60 @@
         gen.endDocument()
 
         self.assertEqual(result.getvalue(),
-                         start + (
+                         self.xml(
                          '<a:g1 xmlns:a="http://example.com/ns">'
                           '<a:g2 xml:lang="en">Hello</a:g2>'
                          '</a:g1>'))
 
+    def test_no_close_file(self):
+        result = self.ioclass()
+        def func(out):
+            gen = XMLGenerator(out)
+            gen.startDocument()
+            gen.startElement("doc", {})
+        func(result)
+        self.assertFalse(result.closed)
+
+class StringXmlgenTest(XmlgenTest, unittest.TestCase):
+    ioclass = StringIO
+
+    def xml(self, doc, encoding='iso-8859-1'):
+        return '<?xml version="1.0" encoding="%s"?>\n%s' % (encoding, doc)
+
+    test_xmlgen_unencodable = None
+
+class BytesXmlgenTest(XmlgenTest, unittest.TestCase):
+    ioclass = BytesIO
+
+    def xml(self, doc, encoding='iso-8859-1'):
+        return ('<?xml version="1.0" encoding="%s"?>\n%s' %
+                (encoding, doc)).encode(encoding, 'xmlcharrefreplace')
+
+class WriterXmlgenTest(BytesXmlgenTest):
+    class ioclass(list):
+        write = list.append
+        closed = False
+
+        def seekable(self):
+            return True
+
+        def tell(self):
+            # return 0 at start and not 0 after start
+            return len(self)
+
+        def getvalue(self):
+            return b''.join(self)
+
+        def close(self):
+            self.closed = True
+
+
+start = b'<?xml version="1.0" encoding="iso-8859-1"?>\n'
+
 
 class XMLFilterBaseTest(unittest.TestCase):
     def test_filter_basic(self):
-        result = StringIO()
+        result = BytesIO()
         gen = XMLGenerator(result)
         filter = XMLFilterBase()
         filter.setContentHandler(gen)
@@ -455,7 +529,7 @@
         filter.endElement("doc")
         filter.endDocument()
 
-        self.assertEqual(result.getvalue(), start + "<doc>content </doc>")
+        self.assertEqual(result.getvalue(), start + b"<doc>content </doc>")
 
 # ===========================================================================
 #
@@ -463,7 +537,7 @@
 #
 # ===========================================================================
 
-with open(TEST_XMLFILE_OUT) as f:
+with open(TEST_XMLFILE_OUT, 'rb') as f:
     xml_test_out = f.read()
 
 class ExpatReaderTest(XmlTestBase):
@@ -472,11 +546,11 @@
 
     def test_expat_file(self):
         parser = create_parser()
-        result = StringIO()
+        result = BytesIO()
         xmlgen = XMLGenerator(result)
 
         parser.setContentHandler(xmlgen)
-        with open(TEST_XMLFILE) as f:
+        with open(TEST_XMLFILE, 'rb') as f:
             parser.parse(f)
 
         self.assertEqual(result.getvalue(), xml_test_out)
@@ -517,13 +591,13 @@
 
         def resolveEntity(self, publicId, systemId):
             inpsrc = InputSource()
-            inpsrc.setByteStream(StringIO("<entity/>"))
+            inpsrc.setByteStream(BytesIO(b"<entity/>"))
             return inpsrc
 
     def test_expat_entityresolver(self):
         parser = create_parser()
         parser.setEntityResolver(self.TestEntityResolver())
-        result = StringIO()
+        result = BytesIO()
         parser.setContentHandler(XMLGenerator(result))
 
         parser.feed('<!DOCTYPE doc [\n')
@@ -533,7 +607,7 @@
         parser.close()
 
         self.assertEqual(result.getvalue(), start +
-                         "<doc><entity></entity></doc>")
+                         b"<doc><entity></entity></doc>")
 
     # ===== Attributes support
 
@@ -602,7 +676,7 @@
 
     def test_expat_inpsource_filename(self):
         parser = create_parser()
-        result = StringIO()
+        result = BytesIO()
         xmlgen = XMLGenerator(result)
 
         parser.setContentHandler(xmlgen)
@@ -612,7 +686,7 @@
 
     def test_expat_inpsource_sysid(self):
         parser = create_parser()
-        result = StringIO()
+        result = BytesIO()
         xmlgen = XMLGenerator(result)
 
         parser.setContentHandler(xmlgen)
@@ -622,12 +696,12 @@
 
     def test_expat_inpsource_stream(self):
         parser = create_parser()
-        result = StringIO()
+        result = BytesIO()
         xmlgen = XMLGenerator(result)
 
         parser.setContentHandler(xmlgen)
         inpsrc = InputSource()
-        with open(TEST_XMLFILE) as f:
+        with open(TEST_XMLFILE, 'rb') as f:
             inpsrc.setByteStream(f)
             parser.parse(inpsrc)
 
@@ -636,7 +710,7 @@
     # ===== IncrementalParser support
 
     def test_expat_incremental(self):
-        result = StringIO()
+        result = BytesIO()
         xmlgen = XMLGenerator(result)
         parser = create_parser()
         parser.setContentHandler(xmlgen)
@@ -645,10 +719,10 @@
         parser.feed("</doc>")
         parser.close()
 
-        self.assertEqual(result.getvalue(), start + "<doc></doc>")
+        self.assertEqual(result.getvalue(), start + b"<doc></doc>")
 
     def test_expat_incremental_reset(self):
-        result = StringIO()
+        result = BytesIO()
         xmlgen = XMLGenerator(result)
         parser = create_parser()
         parser.setContentHandler(xmlgen)
@@ -656,7 +730,7 @@
         parser.feed("<doc>")
         parser.feed("text")
 
-        result = StringIO()
+        result = BytesIO()
         xmlgen = XMLGenerator(result)
         parser.setContentHandler(xmlgen)
         parser.reset()
@@ -666,12 +740,12 @@
         parser.feed("</doc>")
         parser.close()
 
-        self.assertEqual(result.getvalue(), start + "<doc>text</doc>")
+        self.assertEqual(result.getvalue(), start + b"<doc>text</doc>")
 
     # ===== Locator support
 
     def test_expat_locator_noinfo(self):
-        result = StringIO()
+        result = BytesIO()
         xmlgen = XMLGenerator(result)
         parser = create_parser()
         parser.setContentHandler(xmlgen)
@@ -685,7 +759,7 @@
         self.assertEqual(parser.getLineNumber(), 1)
 
     def test_expat_locator_withinfo(self):
-        result = StringIO()
+        result = BytesIO()
         xmlgen = XMLGenerator(result)
         parser = create_parser()
         parser.setContentHandler(xmlgen)
@@ -706,7 +780,7 @@
         parser = create_parser()
         parser.setContentHandler(ContentHandler()) # do nothing
         source = InputSource()
-        source.setByteStream(StringIO("<foo bar foobar>"))   #ill-formed
+        source.setByteStream(BytesIO(b"<foo bar foobar>"))   #ill-formed
         name = "a file name"
         source.setSystemId(name)
         try:
@@ -797,7 +871,9 @@
 def test_main():
     run_unittest(MakeParserTest,
                  SaxutilsTest,
-                 XmlgenTest,
+                 StringXmlgenTest,
+                 BytesXmlgenTest,
+                 WriterXmlgenTest,
                  ExpatReaderTest,
                  ErrorReportingTest,
                  XmlReaderTest)
diff -r 81b2a30da853 Lib/xml/sax/saxutils.py
--- a/Lib/xml/sax/saxutils.py	Sun Jan 20 16:35:09 2013 +0200
+++ b/Lib/xml/sax/saxutils.py	Sun Jan 20 17:24:13 2013 +0200
@@ -4,18 +4,10 @@
 """
 
 import os, urllib.parse, urllib.request
+import io
 from . import handler
 from . import xmlreader
 
-# See whether the xmlcharrefreplace error handler is
-# supported
-try:
-    from codecs import xmlcharrefreplace_errors
-    _error_handling = "xmlcharrefreplace"
-    del xmlcharrefreplace_errors
-except ImportError:
-    _error_handling = "strict"
-
 def __dict_replace(s, d):
     """Replace substrings of a string using a dictionary."""
     for key, value in d.items():
@@ -75,15 +67,55 @@
         data = '"%s"' % data
     return data
 
+def _wrap(obj):
+    class _wrapper:
+        __class__ = obj.__class__
+        def __getattr__(self, name):
+            return getattr(obj, name)
+    return _wrapper()
+
 
 class XMLGenerator(handler.ContentHandler):
 
     def __init__(self, out=None, encoding="iso-8859-1", short_empty_elements=False):
+        handler.ContentHandler.__init__(self)
         if out is None:
             import sys
             out = sys.stdout
-        handler.ContentHandler.__init__(self)
-        self._out = out
+        elif isinstance(out, io.TextIOBase):
+            # use a text writer as is
+            pass
+        else:
+            # wrap a binary writer with TextIOWrapper
+            if isinstance(out, io.BufferedIOBase):
+                # Keep the original file open when the TextIOWrapper is
+                # destroyed
+                out = _wrap(out)
+                out.close = lambda: None
+            elif isinstance(out, io.RawIOBase):
+                out = io.BufferedWriter(out)
+                # Keep the original file open when the TextIOWrapper is
+                # destroyed
+                out.close = lambda: None
+            else:
+                # This is to handle passed objects that aren't in the
+                # IOBase hierarchy, but just have a write method
+                writer = out
+                out = io.BufferedIOBase()
+                out.writable = lambda: True
+                out.write = writer.write
+                try:
+                    # TextIOWrapper uses this methods to determine
+                    # if BOM (for UTF-16, etc) should be added
+                    out.seekable = writer.seekable
+                    out.tell = writer.tell
+                except AttributeError:
+                    pass
+            out = io.TextIOWrapper(out, encoding=encoding,
+                                    errors='xmlcharrefreplace',
+                                    newline='\n')
+        self._write = out.write
+        self._flush = out.flush
         self._ns_contexts = [{}] # contains uri -> prefix dicts
         self._current_context = self._ns_contexts[-1]
         self._undeclared_ns_maps = []
@@ -91,12 +123,6 @@
         self._short_empty_elements = short_empty_elements
         self._pending_start_element = False
 
-    def _write(self, text):
-        if isinstance(text, str):
-            self._out.write(text)
-        else:
-            self._out.write(text.encode(self._encoding, _error_handling))
-
     def _qname(self, name):
         """Builds a qualified name from a (ns_url, localname) pair"""
         if name[0]:
@@ -125,6 +151,9 @@
         self._write('<?xml version="1.0" encoding="%s"?>\n' %
                         self._encoding)
 
+    def endDocument(self):
+        self._flush()
+
     def startPrefixMapping(self, prefix, uri):
         self._ns_contexts.append(self._current_context.copy())
         self._current_context[uri] = prefix
@@ -157,9 +186,9 @@
 
         for prefix, uri in self._undeclared_ns_maps:
             if prefix:
-                self._out.write(' xmlns:%s="%s"' % (prefix, uri))
+                self._write(' xmlns:%s="%s"' % (prefix, uri))
             else:
-                self._out.write(' xmlns="%s"' % uri)
+                self._write(' xmlns="%s"' % uri)
         self._undeclared_ns_maps = []
 
         for (name, value) in attrs.items():