Issue #9837: The read() method of ZipExtFile objects (as returned by
ZipFile.open()) could return more bytes than requested.
diff --git a/Lib/zipfile.py b/Lib/zipfile.py
index c47c3cc..bcdb2b8 100644
--- a/Lib/zipfile.py
+++ b/Lib/zipfile.py
@@ -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: