Issue #7820: The parser tokenizer restores all bytes in the right if the BOM
check fails.
Fix an assertion in pydebug mode.
diff --git a/Lib/test/test_pep263.py b/Lib/test/test_pep263.py
index e4faa9f..9286467 100644
--- a/Lib/test/test_pep263.py
+++ b/Lib/test/test_pep263.py
@@ -30,6 +30,17 @@
self.assertEqual(d['a'], d['b'])
self.assertEqual(len(d['a']), len(d['b']))
+ def test_issue7820(self):
+ # Ensure that check_bom() restores all bytes in the right order if
+ # check_bom() fails in pydebug mode: a buffer starts with the first
+ # byte of a valid BOM, but next bytes are different
+
+ # one byte in common with the UTF-16-LE BOM
+ self.assertRaises(SyntaxError, eval, '\xff\x20')
+
+ # two bytes in common with the UTF-8 BOM
+ self.assertRaises(SyntaxError, eval, '\xef\xbb\x20')
+
def test_main():
test_support.run_unittest(PEP263Test)