Issue #9837: The read() method of ZipExtFile objects (as returned by
ZipFile.open()) could return more bytes than requested.
diff --git a/Lib/test/test_zipfile.py b/Lib/test/test_zipfile.py
index 82b4061..380e63b 100644
--- a/Lib/test/test_zipfile.py
+++ b/Lib/test/test_zipfile.py
@@ -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)