Issue #13612: handle unknown encodings without a buffer overflow.

This affects pyexpat and _elementtree. PyExpat_CAPI now exposes a new
function - DefaultUnknownEncodingHandler.

Based on a patch by Serhiy Storchaka.

1 files changed, 92 insertions, 0 deletions

diff --git a/Lib/test/test_xml_etree.py b/Lib/test/test_xml_etree.py
index 746ca28..1722292 100644
--- a/Lib/test/test_xml_etree.py
+++ b/Lib/test/test_xml_etree.py
@@ -690,6 +690,98 @@ class ElementTreeTest(unittest.TestCase):
         check("cp437", '\u221a')
         check("mac-roman", '\u02da')
 
+        def xml(encoding):
+            return "<?xml version='1.0' encoding='%s'?><xml />" % encoding
+        def bxml(encoding):
+            return xml(encoding).encode(encoding)
+        supported_encodings = [
+            'ascii', 'utf-8', 'utf-8-sig', 'utf-16', 'utf-16be', 'utf-16le',
+            'iso8859-1', 'iso8859-2', 'iso8859-3', 'iso8859-4', 'iso8859-5',
+            'iso8859-6', 'iso8859-7', 'iso8859-8', 'iso8859-9', 'iso8859-10',
+            'iso8859-13', 'iso8859-14', 'iso8859-15', 'iso8859-16',
+            'cp437', 'cp720', 'cp737', 'cp775', 'cp850', 'cp852',
+            'cp855', 'cp856', 'cp857', 'cp858', 'cp860', 'cp861', 'cp862',
+            'cp863', 'cp865', 'cp866', 'cp869', 'cp874', 'cp1006', 'cp1250',
+            'cp1251', 'cp1252', 'cp1253', 'cp1254', 'cp1255', 'cp1256',
+            'cp1257', 'cp1258',
+            'mac-cyrillic', 'mac-greek', 'mac-iceland', 'mac-latin2',
+            'mac-roman', 'mac-turkish',
+            'iso2022-jp', 'iso2022-jp-1', 'iso2022-jp-2', 'iso2022-jp-2004',
+            'iso2022-jp-3', 'iso2022-jp-ext',
+            'koi8-r', 'koi8-u',
+            'hz', 'ptcp154',
+        ]
+        for encoding in supported_encodings:
+            self.assertEqual(ET.tostring(ET.XML(bxml(encoding))), b'<xml />')
+
+        unsupported_ascii_compatible_encodings = [
+            'big5', 'big5hkscs',
+            'cp932', 'cp949', 'cp950',
+            'euc-jp', 'euc-jis-2004', 'euc-jisx0213', 'euc-kr',
+            'gb2312', 'gbk', 'gb18030',
+            'iso2022-kr', 'johab',
+            'shift-jis', 'shift-jis-2004', 'shift-jisx0213',
+            'utf-7',
+        ]
+        for encoding in unsupported_ascii_compatible_encodings:
+            self.assertRaises(ValueError, ET.XML, bxml(encoding))
+
+        unsupported_ascii_incompatible_encodings = [
+            'cp037', 'cp424', 'cp500', 'cp864', 'cp875', 'cp1026', 'cp1140',
+            'utf_32', 'utf_32_be', 'utf_32_le',
+        ]
+        for encoding in unsupported_ascii_incompatible_encodings:
+            self.assertRaises(ET.ParseError, ET.XML, bxml(encoding))
+
+        self.assertRaises(ValueError, ET.XML, xml('undefined').encode('ascii'))
+        self.assertRaises(LookupError, ET.XML, xml('xxx').encode('ascii'))
+
+        def xml(encoding):
+            return "<?xml version='1.0' encoding='%s'?><xml />" % encoding
+        def bxml(encoding):
+            return xml(encoding).encode(encoding)
+        supported_encodings = [
+            'ascii', 'utf-8', 'utf-8-sig', 'utf-16', 'utf-16be', 'utf-16le',
+            'iso8859-1', 'iso8859-2', 'iso8859-3', 'iso8859-4', 'iso8859-5',
+            'iso8859-6', 'iso8859-7', 'iso8859-8', 'iso8859-9', 'iso8859-10',
+            'iso8859-13', 'iso8859-14', 'iso8859-15', 'iso8859-16',
+            'cp437', 'cp720', 'cp737', 'cp775', 'cp850', 'cp852',
+            'cp855', 'cp856', 'cp857', 'cp858', 'cp860', 'cp861', 'cp862',
+            'cp863', 'cp865', 'cp866', 'cp869', 'cp874', 'cp1006', 'cp1250',
+            'cp1251', 'cp1252', 'cp1253', 'cp1254', 'cp1255', 'cp1256',
+            'cp1257', 'cp1258',
+            'mac-cyrillic', 'mac-greek', 'mac-iceland', 'mac-latin2',
+            'mac-roman', 'mac-turkish',
+            'iso2022-jp', 'iso2022-jp-1', 'iso2022-jp-2', 'iso2022-jp-2004',
+            'iso2022-jp-3', 'iso2022-jp-ext',
+            'koi8-r', 'koi8-u',
+            'hz', 'ptcp154',
+        ]
+        for encoding in supported_encodings:
+            self.assertEqual(ET.tostring(ET.XML(bxml(encoding))), b'<xml />')
+
+        unsupported_ascii_compatible_encodings = [
+            'big5', 'big5hkscs',
+            'cp932', 'cp949', 'cp950',
+            'euc-jp', 'euc-jis-2004', 'euc-jisx0213', 'euc-kr',
+            'gb2312', 'gbk', 'gb18030',
+            'iso2022-kr', 'johab',
+            'shift-jis', 'shift-jis-2004', 'shift-jisx0213',
+            'utf-7',
+        ]
+        for encoding in unsupported_ascii_compatible_encodings:
+            self.assertRaises(ValueError, ET.XML, bxml(encoding))
+
+        unsupported_ascii_incompatible_encodings = [
+            'cp037', 'cp424', 'cp500', 'cp864', 'cp875', 'cp1026', 'cp1140',
+            'utf_32', 'utf_32_be', 'utf_32_le',
+        ]
+        for encoding in unsupported_ascii_incompatible_encodings:
+            self.assertRaises(ET.ParseError, ET.XML, bxml(encoding))
+
+        self.assertRaises(ValueError, ET.XML, xml('undefined').encode('ascii'))
+        self.assertRaises(LookupError, ET.XML, xml('xxx').encode('ascii'))
+
     def test_methods(self):
         # Test serialization methods.