Issue #1531: Read fileobj from the current offset, do not seek to
the start.
(will backport to 2.5)
diff --git a/Lib/tarfile.py b/Lib/tarfile.py
index ee9922c..ae24291 100644
--- a/Lib/tarfile.py
+++ b/Lib/tarfile.py
@@ -1558,7 +1558,8 @@
self.closed = False
self.members = [] # list of members as TarInfo objects
self._loaded = False # flag if all members have been read
- self.offset = 0L # current position in the archive file
+ self.offset = self.fileobj.tell()
+ # current position in the archive file
self.inodes = {} # dictionary caching the inodes of
# archive members already added
diff --git a/Lib/test/test_tarfile.py b/Lib/test/test_tarfile.py
index 1f08258..a280bdd 100644
--- a/Lib/test/test_tarfile.py
+++ b/Lib/test/test_tarfile.py
@@ -160,6 +160,38 @@
tar = tarfile.open(fileobj=fobj, mode=self.mode)
self.assertEqual(tar.name, None)
+ def test_fileobj_with_offset(self):
+ # Skip the first member and store values from the second member
+ # of the testtar.
+ tar = tarfile.open(self.tarname, mode=self.mode)
+ tar.next()
+ t = tar.next()
+ name = t.name
+ offset = t.offset
+ data = tar.extractfile(t).read()
+ tar.close()
+
+ # Open the testtar and seek to the offset of the second member.
+ if self.mode.endswith(":gz"):
+ _open = gzip.GzipFile
+ elif self.mode.endswith(":bz2"):
+ _open = bz2.BZ2File
+ else:
+ _open = open
+ fobj = _open(self.tarname, "rb")
+ fobj.seek(offset)
+
+ # Test if the tarfile starts with the second member.
+ tar = tar.open(self.tarname, mode="r:", fileobj=fobj)
+ t = tar.next()
+ self.assertEqual(t.name, name)
+ # Read to the end of fileobj and test if seeking back to the
+ # beginning works.
+ tar.getmembers()
+ self.assertEqual(tar.extractfile(t).read(), data,
+ "seek back did not work")
+ tar.close()
+
def test_fail_comp(self):
# For Gzip and Bz2 Tests: fail with a ReadError on an uncompressed file.
if self.mode == "r:":