From 1de19ac7dab2f75a5886656b7272c6fb009ddd2d Mon Sep 17 00:00:00 2001 From: Nadeem Vawda Date: Wed, 4 Dec 2013 23:01:15 +0100 Subject: [PATCH] #19839: Fix regression in bz2 module's handling of non-bzip2 data at EOF. --- Lib/bz2.py | 29 +++++++++++++++++++---------- Lib/test/test_bz2.py | 30 +++++++++++++++++++++++++++++- Misc/NEWS | 3 +++ 3 files changed, 51 insertions(+), 11 deletions(-) diff --git a/Lib/bz2.py b/Lib/bz2.py index c3075073f0e..1de8f3ca7d4 100644 --- a/Lib/bz2.py +++ b/Lib/bz2.py @@ -199,8 +199,15 @@ class BZ2File(io.BufferedIOBase): # Continue to next stream. if self._decompressor.eof: self._decompressor = BZ2Decompressor() - - self._buffer = self._decompressor.decompress(rawblock) + try: + self._buffer = self._decompressor.decompress(rawblock) + except OSError: + # Trailing data isn't a valid bzip2 stream. We're done here. + self._mode = _MODE_READ_EOF + self._size = self._pos + return False + else: + self._buffer = self._decompressor.decompress(rawblock) self._buffer_offset = 0 return True @@ -488,17 +495,19 @@ def decompress(data): For incremental decompression, use a BZ2Decompressor object instead. """ - if len(data) == 0: - return b"" - results = [] - while True: + while data: decomp = BZ2Decompressor() - results.append(decomp.decompress(data)) + try: + res = decomp.decompress(data) + except OSError: + if results: + break # Leftover data is not a valid bzip2 stream; ignore it. + else: + raise # Error on the first iteration; bail out. + results.append(res) if not decomp.eof: raise ValueError("Compressed data ended before the " "end-of-stream marker was reached") - if not decomp.unused_data: - return b"".join(results) - # There is unused data left over. Proceed to next stream. data = decomp.unused_data + return b"".join(results) diff --git a/Lib/test/test_bz2.py b/Lib/test/test_bz2.py index 6764e59553c..98557f25101 100644 --- a/Lib/test/test_bz2.py +++ b/Lib/test/test_bz2.py @@ -49,6 +49,7 @@ class BaseTest(unittest.TestCase): TEXT = b''.join(TEXT_LINES) DATA = b'BZh91AY&SY.\xc8N\x18\x00\x01>_\x80\x00\x10@\x02\xff\xf0\x01\x07n\x00?\xe7\xff\xe00\x01\x99\xaa\x00\xc0\x03F\x86\x8c#&\x83F\x9a\x03\x06\xa6\xd0\xa6\x93M\x0fQ\xa7\xa8\x06\x804hh\x12$\x11\xa4i4\xf14S\xd2\x88\xe5\xcd9gd6\x0b\n\xe9\x9b\xd5\x8a\x99\xf7\x08.K\x8ev\xfb\xf7xw\xbb\xdf\xa1\x92\xf1\xdd|/";\xa2\xba\x9f\xd5\xb1#A\xb6\xf6\xb3o\xc9\xc5y\\\xebO\xe7\x85\x9a\xbc\xb6f8\x952\xd5\xd7"%\x89>V,\xf7\xa6z\xe2\x9f\xa3\xdf\x11\x11"\xd6E)I\xa9\x13^\xca\xf3r\xd0\x03U\x922\xf26\xec\xb6\xed\x8b\xc3U\x13\x9d\xc5\x170\xa4\xfa^\x92\xacDF\x8a\x97\xd6\x19\xfe\xdd\xb8\xbd\x1a\x9a\x19\xa3\x80ankR\x8b\xe5\xd83]\xa9\xc6\x08\x82f\xf6\xb9"6l$\xb8j@\xc0\x8a\xb0l1..\xbak\x83ls\x15\xbc\xf4\xc1\x13\xbe\xf8E\xb8\x9d\r\xa8\x9dk\x84\xd3n\xfa\xacQ\x07\xb1%y\xaav\xb4\x08\xe0z\x1b\x16\xf5\x04\xe9\xcc\xb9\x08z\x1en7.G\xfc]\xc9\x14\xe1B@\xbb!8`' EMPTY_DATA = b'BZh9\x17rE8P\x90\x00\x00\x00\x00' + BAD_DATA = b'this is not a valid bzip2 file' def setUp(self): self.filename = TESTFN @@ -79,9 +80,10 @@ class BaseTest(unittest.TestCase): class BZ2FileTest(BaseTest): "Test BZ2File type miscellaneous methods." - def createTempFile(self, streams=1): + def createTempFile(self, streams=1, suffix=b""): with open(self.filename, "wb") as f: f.write(self.DATA * streams) + f.write(suffix) def testBadArgs(self): with self.assertRaises(TypeError): @@ -103,6 +105,11 @@ class BZ2FileTest(BaseTest): self.assertRaises(TypeError, bz2f.read, None) self.assertEqual(bz2f.read(), self.TEXT) + def testReadBadFile(self): + self.createTempFile(streams=0, suffix=self.BAD_DATA) + with BZ2File(self.filename) as bz2f: + self.assertRaises(OSError, bz2f.read) + def testReadMultiStream(self): self.createTempFile(streams=5) with BZ2File(self.filename) as bz2f: @@ -122,6 +129,16 @@ class BZ2FileTest(BaseTest): finally: bz2._BUFFER_SIZE = buffer_size + def testReadTrailingJunk(self): + self.createTempFile(suffix=self.BAD_DATA) + with BZ2File(self.filename) as bz2f: + self.assertEqual(bz2f.read(), self.TEXT) + + def testReadMultiStreamTrailingJunk(self): + self.createTempFile(streams=5, suffix=self.BAD_DATA) + with BZ2File(self.filename) as bz2f: + self.assertEqual(bz2f.read(), self.TEXT * 5) + def testRead0(self): self.createTempFile() with BZ2File(self.filename) as bz2f: @@ -707,10 +724,21 @@ class CompressDecompressTest(BaseTest): def testDecompressIncomplete(self): self.assertRaises(ValueError, bz2.decompress, self.DATA[:-10]) + def testDecompressBadData(self): + self.assertRaises(OSError, bz2.decompress, self.BAD_DATA) + def testDecompressMultiStream(self): text = bz2.decompress(self.DATA * 5) self.assertEqual(text, self.TEXT * 5) + def testDecompressTrailingJunk(self): + text = bz2.decompress(self.DATA + self.BAD_DATA) + self.assertEqual(text, self.TEXT) + + def testDecompressMultiStreamTrailingJunk(self): + text = bz2.decompress(self.DATA * 5 + self.BAD_DATA) + self.assertEqual(text, self.TEXT * 5) + class OpenTest(BaseTest): def test_binary_modes(self): diff --git a/Misc/NEWS b/Misc/NEWS index b2f18addf48..71fce50511e 100644 --- a/Misc/NEWS +++ b/Misc/NEWS @@ -18,6 +18,9 @@ Core and Builtins Library ------- +- Issue #19839: Fix regression in bz2 module's handling of non-bzip2 data at + EOF. + - Issue #19138: doctest's IGNORE_EXCEPTION_DETAIL now allows a match when no exception detail exists (no colon following the exception's name, or a colon does follow but no text follows the colon).