[Python-checkins] r52524 - in python/trunk: Lib/tarfile.py Misc/NEWS

Sun Oct 29 10:16:12 CET 2006

Author: georg.brandl
Date: Sun Oct 29 10:16:12 2006
New Revision: 52524
Modified:
 python/trunk/Lib/tarfile.py
 python/trunk/Misc/NEWS
Log:
Patch #1583880: fix tarfile's problems with long names and posix/
GNU modes.
Modified: python/trunk/Lib/tarfile.py
==============================================================================

--- python/trunk/Lib/tarfile.py	(original)
+++ python/trunk/Lib/tarfile.py	Sun Oct 29 10:16:12 2006
@@ -49,6 +49,7 @@
 import errno
 import time
 import struct
+import copy
 
 if sys.platform == 'mac':
 # This module needs work for MacOS9, especially in the area of pathname
@@ -793,7 +794,6 @@
 """Construct a TarInfo object. name is the optional name
 of the member.
 """
-
 self.name = name # member name (dirnames must end with '/')
 self.mode = 0666 # file permissions
 self.uid = 0 # user id
@@ -807,8 +807,6 @@
 self.gname = "group" # group name
 self.devmajor = 0 # device major number
 self.devminor = 0 # device minor number
- self.prefix = "" # prefix to filename or information
- # about sparse files
 
 self.offset = 0 # the tar header starts here
 self.offset_data = 0 # the file's data starts here
@@ -840,24 +838,70 @@
 tarinfo.gname = buf[297:329].rstrip(NUL)
 tarinfo.devmajor = nti(buf[329:337])
 tarinfo.devminor = nti(buf[337:345])
- tarinfo.prefix = buf[345:500]
+ prefix = buf[345:500].rstrip(NUL)
+
+ if prefix and not tarinfo.issparse():
+ tarinfo.name = prefix + "/" + tarinfo.name
 
 if tarinfo.chksum not in calc_chksums(buf):
 raise ValueError("invalid header")
 return tarinfo
 
 def tobuf(self, posix=False):
- """Return a tar header block as a 512 byte string.
+ """Return a tar header as a string of 512 byte blocks.
 """
+ buf = ""
+ type = self.type
+ prefix = ""
+
+ if self.name.endswith("/"):
+ type = DIRTYPE
+
+ name = normpath(self.name)
+
+ if type == DIRTYPE:
+ # directories should end with '/'
+ name += "/"
+
+ linkname = self.linkname
+ if linkname:
+ # if linkname is empty we end up with a '.'
+ linkname = normpath(linkname)
+
+ if posix:
+ if self.size > MAXSIZE_MEMBER:
+ raise ValueError("file is too large (>= 8 GB)")
+
+ if len(self.linkname) > LENGTH_LINK:
+ raise ValueError("linkname is too long (>%d)" % (LENGTH_LINK))
+
+ if len(name) > LENGTH_NAME:
+ prefix = name[:LENGTH_PREFIX + 1]
+ while prefix and prefix[-1] != "/":
+ prefix = prefix[:-1]
+
+ name = name[len(prefix):]
+ prefix = prefix[:-1]
+
+ if not prefix or len(name) > LENGTH_NAME:
+ raise ValueError("name is too long")
+
+ else:
+ if len(self.linkname) > LENGTH_LINK:
+ buf += self._create_gnulong(self.linkname, GNUTYPE_LONGLINK)
+
+ if len(name) > LENGTH_NAME:
+ buf += self._create_gnulong(name, GNUTYPE_LONGNAME)
+
 parts = [
- stn(self.name, 100),
+ stn(name, 100),
 itn(self.mode & 07777, 8, posix),
 itn(self.uid, 8, posix),
 itn(self.gid, 8, posix),
 itn(self.size, 12, posix),
 itn(self.mtime, 12, posix),
 " ", # checksum field
- self.type,
+ type,
 stn(self.linkname, 100),
 stn(MAGIC, 6),
 stn(VERSION, 2),
@@ -865,15 +909,38 @@
 stn(self.gname, 32),
 itn(self.devmajor, 8, posix),
 itn(self.devminor, 8, posix),
- stn(self.prefix, 155)
+ stn(prefix, 155)
 ]
 
- buf = struct.pack("%ds" % BLOCKSIZE, "".join(parts))
+ buf += struct.pack("%ds" % BLOCKSIZE, "".join(parts))
 chksum = calc_chksums(buf)[0]
- buf = buf[:148] + "%06o0円" % chksum + buf[155:]
+ buf = buf[:-364] + "%06o0円" % chksum + buf[-357:]
 self.buf = buf
 return buf
 
+ def _create_gnulong(self, name, type):
+ """Create a GNU longname/longlink header from name.
+ It consists of an extended tar header, with the length
+ of the longname as size, followed by data blocks,
+ which contain the longname as a null terminated string.
+ """
+ name += NUL
+
+ tarinfo = self.__class__()
+ tarinfo.name = "././@LongLink"
+ tarinfo.type = type
+ tarinfo.mode = 0
+ tarinfo.size = len(name)
+
+ # create extended header
+ buf = tarinfo.tobuf()
+ # create name blocks
+ buf += name
+ blocks, remainder = divmod(len(name), BLOCKSIZE)
+ if remainder > 0:
+ buf += (BLOCKSIZE - remainder) * NUL
+ return buf
+
 def isreg(self):
 return self.type in REGULAR_TYPES
 def isfile(self):
@@ -1377,50 +1444,11 @@
 """
 self._check("aw")
 
- tarinfo.name = normpath(tarinfo.name)
- if tarinfo.isdir():
- # directories should end with '/'
- tarinfo.name += "/"
-
- if tarinfo.linkname:
- tarinfo.linkname = normpath(tarinfo.linkname)
-
- if tarinfo.size > MAXSIZE_MEMBER:
- if self.posix:
- raise ValueError("file is too large (>= 8 GB)")
- else:
- self._dbg(2, "tarfile: Created GNU tar largefile header")
-
-
- if len(tarinfo.linkname) > LENGTH_LINK:
- if self.posix:
- raise ValueError("linkname is too long (>%d)" % (LENGTH_LINK))
- else:
- self._create_gnulong(tarinfo.linkname, GNUTYPE_LONGLINK)
- tarinfo.linkname = tarinfo.linkname[:LENGTH_LINK -1]
- self._dbg(2, "tarfile: Created GNU tar extension LONGLINK")
-
- if len(tarinfo.name) > LENGTH_NAME:
- if self.posix:
- prefix = tarinfo.name[:LENGTH_PREFIX + 1]
- while prefix and prefix[-1] != "/":
- prefix = prefix[:-1]
-
- name = tarinfo.name[len(prefix):]
- prefix = prefix[:-1]
+ tarinfo = copy.copy(tarinfo)
 
- if not prefix or len(name) > LENGTH_NAME:
- raise ValueError("name is too long (>%d)" % (LENGTH_NAME))
-
- tarinfo.name = name
- tarinfo.prefix = prefix
- else:
- self._create_gnulong(tarinfo.name, GNUTYPE_LONGNAME)
- tarinfo.name = tarinfo.name[:LENGTH_NAME - 1]
- self._dbg(2, "tarfile: Created GNU tar extension LONGNAME")
-
- self.fileobj.write(tarinfo.tobuf(self.posix))
- self.offset += BLOCKSIZE
+ buf = tarinfo.tobuf(self.posix)
+ self.fileobj.write(buf)
+ self.offset += len(buf)
 
 # If there's data to follow, append it.
 if fileobj is not None:
@@ -1779,12 +1807,6 @@
 if tarinfo.isreg() and tarinfo.name.endswith("/"):
 tarinfo.type = DIRTYPE
 
- # The prefix field is used for filenames > 100 in
- # the POSIX standard.
- # name = prefix + '/' + name
- tarinfo.name = normpath(os.path.join(tarinfo.prefix.rstrip(NUL),
- tarinfo.name))
-
 # Directory names should have a '/' at the end.
 if tarinfo.isdir():
 tarinfo.name += "/"
@@ -1909,10 +1931,6 @@
 self.offset += self._block(tarinfo.size)
 tarinfo.size = origsize
 
- # Clear the prefix field so that it is not used
- # as a pathname in next().
- tarinfo.prefix = ""
-
 return tarinfo
 
 #--------------------------------------------------------------------------
@@ -1970,31 +1988,6 @@
 else:
 return TarIter(self)
 
- def _create_gnulong(self, name, type):
- """Write a GNU longname/longlink member to the TarFile.
- It consists of an extended tar header, with the length
- of the longname as size, followed by data blocks,
- which contain the longname as a null terminated string.
- """
- name += NUL
-
- tarinfo = TarInfo()
- tarinfo.name = "././@LongLink"
- tarinfo.type = type
- tarinfo.mode = 0
- tarinfo.size = len(name)
-
- # write extended header
- self.fileobj.write(tarinfo.tobuf())
- self.offset += BLOCKSIZE
- # write name blocks
- self.fileobj.write(name)
- blocks, remainder = divmod(tarinfo.size, BLOCKSIZE)
- if remainder > 0:
- self.fileobj.write(NUL * (BLOCKSIZE - remainder))
- blocks += 1
- self.offset += blocks * BLOCKSIZE
-
 def _dbg(self, level, msg):
 """Write debugging output to sys.stderr.
 """
Modified: python/trunk/Misc/NEWS
==============================================================================
--- python/trunk/Misc/NEWS	(original)
+++ python/trunk/Misc/NEWS	Sun Oct 29 10:16:12 2006
@@ -89,6 +89,9 @@
 Library
 -------
 
+- Patch #1583880: fix tarfile's problems with long names and posix/
+ GNU modes.
+
 - Bug #1586448: the compiler module now emits the same bytecode for
 list comprehensions as the builtin compiler, using the LIST_APPEND
 opcode.
