Merged revisions 81667 via svnmerge from
svn+ssh://pythondev@svn.python.org/python/trunk
........
r81667 | lars.gustaebel | 2010-06-03 14:34:14 +0200 (Thu, 03 Jun 2010) | 8 lines
Issue #8741: Fixed the TarFile.makelink() method that is responsible
for extracting symbolic and hard link entries as regular files as a
work-around on platforms that do not support filesystem links.
This stopped working reliably after a change in r74571. I also added
a few tests for this functionality.
........
diff --git a/Lib/tarfile.py b/Lib/tarfile.py
index 8559e96..31967dd 100644
--- a/Lib/tarfile.py
+++ b/Lib/tarfile.py
@@ -2163,8 +2163,7 @@
raise StreamError("cannot extract (sym)link as file object")
else:
# A (sym)link's file object is its target's file object.
- return self.extractfile(self._getmember(tarinfo.linkname,
- tarinfo))
+ return self.extractfile(self._find_link_target(tarinfo))
else:
# If there's no data associated with the member (directory, chrdev,
# blkdev, etc.), return None instead of a file object.
@@ -2273,27 +2272,21 @@
(platform limitation), we try to make a copy of the referenced file
instead of a link.
"""
- try:
+ if hasattr(os, "symlink") and hasattr(os, "link"):
+ # For systems that support symbolic and hard links.
if tarinfo.issym():
os.symlink(tarinfo.linkname, targetpath)
else:
# See extract().
- os.link(tarinfo._link_target, targetpath)
- except AttributeError:
- if tarinfo.issym():
- linkpath = os.path.dirname(tarinfo.name) + "/" + \
- tarinfo.linkname
- else:
- linkpath = tarinfo.linkname
-
+ if os.path.exists(tarinfo._link_target):
+ os.link(tarinfo._link_target, targetpath)
+ else:
+ self._extract_member(self._find_link_target(tarinfo), targetpath)
+ else:
try:
- self._extract_member(self.getmember(linkpath), targetpath)
- except (EnvironmentError, KeyError) as e:
- linkpath = linkpath.replace("/", os.sep)
- try:
- shutil.copy2(linkpath, targetpath)
- except EnvironmentError as e:
- raise IOError("link could not be created")
+ self._extract_member(self._find_link_target(tarinfo), targetpath)
+ except KeyError:
+ raise ExtractError("unable to resolve link inside archive")
def chown(self, tarinfo, targetpath):
"""Set owner of targetpath according to tarinfo.
@@ -2392,21 +2385,28 @@
#--------------------------------------------------------------------------
# Little helper methods:
- def _getmember(self, name, tarinfo=None):
+ def _getmember(self, name, tarinfo=None, normalize=False):
"""Find an archive member by name from bottom to top.
If tarinfo is given, it is used as the starting point.
"""
# Ensure that all members have been loaded.
members = self.getmembers()
- if tarinfo is None:
- end = len(members)
- else:
- end = members.index(tarinfo)
+ # Limit the member search list up to tarinfo.
+ if tarinfo is not None:
+ members = members[:members.index(tarinfo)]
- for i in range(end - 1, -1, -1):
- if name == members[i].name:
- return members[i]
+ if normalize:
+ name = os.path.normpath(name)
+
+ for member in reversed(members):
+ if normalize:
+ member_name = os.path.normpath(member.name)
+ else:
+ member_name = member.name
+
+ if name == member_name:
+ return member
def _load(self):
"""Read through the entire archive file and look for readable
@@ -2427,6 +2427,25 @@
if mode is not None and self.mode not in mode:
raise IOError("bad operation for mode %r" % self.mode)
+ def _find_link_target(self, tarinfo):
+ """Find the target member of a symlink or hardlink member in the
+ archive.
+ """
+ if tarinfo.issym():
+ # Always search the entire archive.
+ linkname = os.path.dirname(tarinfo.name) + "/" + tarinfo.linkname
+ limit = None
+ else:
+ # Search the archive before the link, because a hard link is
+ # just a reference to an already archived file.
+ linkname = tarinfo.linkname
+ limit = tarinfo
+
+ member = self._getmember(linkname, tarinfo=limit, normalize=True)
+ if member is None:
+ raise KeyError("linkname %r not found" % linkname)
+ return member
+
def __iter__(self):
"""Provide an iterator object.
"""