[Python-checkins] r84737 - in python/branches/py3k: Lib/test/test_zipfile.py Lib/zipfile.py Misc/NEWS

Sun Sep 12 16:51:21 CEST 2010

Author: antoine.pitrou
Date: Sun Sep 12 16:51:20 2010
New Revision: 84737
Log:
Issue #9837: The read() method of ZipExtFile objects (as returned by
ZipFile.open()) could return more bytes than requested.
Modified:
 python/branches/py3k/Lib/test/test_zipfile.py
 python/branches/py3k/Lib/zipfile.py
 python/branches/py3k/Misc/NEWS
Modified: python/branches/py3k/Lib/test/test_zipfile.py
==============================================================================

--- python/branches/py3k/Lib/test/test_zipfile.py	(original)
+++ python/branches/py3k/Lib/test/test_zipfile.py	Sun Sep 12 16:51:20 2010
@@ -939,6 +939,26 @@
 def test_read_with_bad_crc_deflated(self):
 self.check_read_with_bad_crc(zipfile.ZIP_DEFLATED)
 
+ def check_read_return_size(self, compression):
+ # Issue #9837: ZipExtFile.read() shouldn't return more bytes
+ # than requested.
+ for test_size in (1, 4095, 4096, 4097, 16384):
+ file_size = test_size + 1
+ junk = b''.join(struct.pack('B', randint(0, 255))
+ for x in range(file_size))
+ with zipfile.ZipFile(io.BytesIO(), "w", compression) as zipf:
+ zipf.writestr('foo', junk)
+ with zipf.open('foo', 'r') as fp:
+ buf = fp.read(test_size)
+ self.assertEqual(len(buf), test_size)
+
+ def test_read_return_size_stored(self):
+ self.check_read_return_size(zipfile.ZIP_STORED)
+
+ @skipUnless(zlib, "requires zlib")
+ def test_read_return_size_deflated(self):
+ self.check_read_return_size(zipfile.ZIP_DEFLATED)
+
 def tearDown(self):
 unlink(TESTFN)
 unlink(TESTFN2)
Modified: python/branches/py3k/Lib/zipfile.py
==============================================================================
--- python/branches/py3k/Lib/zipfile.py	(original)
+++ python/branches/py3k/Lib/zipfile.py	Sun Sep 12 16:51:20 2010
@@ -564,17 +564,20 @@
 """Read and return up to n bytes.
 If the argument is omitted, None, or negative, data is read and returned until EOF is reached..
 """
-
 buf = b''
- while n < 0 or n is None or n > len(buf):
- data = self.read1(n)
+ if n is None:
+ n = -1
+ while True:
+ if n < 0:
+ data = self.read1(n)
+ elif n > len(buf):
+ data = self.read1(n - len(buf))
+ else:
+ return buf
 if len(data) == 0:
 return buf
-
 buf += data
 
- return buf
-
 def _update_crc(self, newdata, eof):
 # Update the CRC using the given data.
 if self._expected_crc is None:
Modified: python/branches/py3k/Misc/NEWS
==============================================================================
--- python/branches/py3k/Misc/NEWS	(original)
+++ python/branches/py3k/Misc/NEWS	Sun Sep 12 16:51:20 2010
@@ -32,6 +32,9 @@
 Library
 -------
 
+- Issue #9837: The read() method of ZipExtFile objects (as returned by
+ ZipFile.open()) could return more bytes than requested.
+
 - Issue #9826: OrderedDict.__repr__ can now handle self-referential
 values: d['x'] = d.
 
