[Python-checkins] cpython (3.3): Close #17666: Fix reading gzip files with an extra field.

Mon Apr 8 21:39:41 CEST 2013

http://hg.python.org/cpython/rev/f78d2605f452
changeset: 83200:f78d2605f452
branch: 3.3
parent: 83194:4d8e9c5ba651
user: Serhiy Storchaka <storchaka at gmail.com>
date: Mon Apr 08 22:35:02 2013 +0300
summary:
 Close #17666: Fix reading gzip files with an extra field.
files:
 Lib/gzip.py | 3 ++-
 Lib/test/test_gzip.py | 7 +++++++
 Misc/NEWS | 2 ++
 3 files changed, 11 insertions(+), 1 deletions(-)

diff --git a/Lib/gzip.py b/Lib/gzip.py
--- a/Lib/gzip.py
+++ b/Lib/gzip.py
@@ -302,7 +302,8 @@
 
 if flag & FEXTRA:
 # Read & discard the extra field, if present
- self._read_exact(struct.unpack("<H", self._read_exact(2)))
+ extra_len, = struct.unpack("<H", self._read_exact(2))
+ self._read_exact(extra_len)
 if flag & FNAME:
 # Read and discard a null-terminated string containing the filename
 while True:
diff --git a/Lib/test/test_gzip.py b/Lib/test/test_gzip.py
--- a/Lib/test/test_gzip.py
+++ b/Lib/test/test_gzip.py
@@ -403,6 +403,13 @@
 with gzip.GzipFile(fileobj=io.BytesIO(truncated[:i])) as f:
 self.assertRaises(EOFError, f.read, 1)
 
+ def test_read_with_extra(self):
+ # Gzip data with an extra field
+ gzdata = (b'\x1f\x8b\x08\x04\xb2\x17cQ\x02\xff'
+ b'\x05\x00Extra'
+ b'\x0bI-.\x01\x002\xd1Mx\x04\x00\x00\x00')
+ with gzip.GzipFile(fileobj=io.BytesIO(gzdata)) as f:
+ self.assertEqual(f.read(), b'Test')
 
 class TestOpen(BaseTest):
 def test_binary_modes(self):
diff --git a/Misc/NEWS b/Misc/NEWS
--- a/Misc/NEWS
+++ b/Misc/NEWS
@@ -21,6 +21,8 @@
 Library
 -------
 
+- Issue #17666: Fix reading gzip files with an extra field.
+
 - Issue #17502: Process DEFAULT values in mock side_effect that returns iterator.
 Patch by Michael Foord.
 
-- 
Repository URL: http://hg.python.org/cpython
