Bug #1704156: Support for unicode strings as input filenames is

neither documented nor intended but works in Python 2.4 under certain
conditions. This stopped working in 2.5 because struct.pack is used.
This small patch restores the old behaviour. A more solid solution is
planned for 2.6.

Lib/tarfile.py

@@ -963,7 +963,7 @@ class TarInfo(object):
             stn(prefix, 155)
         ]
 
-        buf += struct.pack("%ds" % BLOCKSIZE, "".join(parts))
+        buf += "".join(parts).ljust(BLOCKSIZE, NUL)
         chksum = calc_chksums(buf[-BLOCKSIZE:])[0]
         buf = buf[:-364] + "%06o\0" % chksum + buf[-357:]
         self.buf = buf