Thanks SilentGhost for your feedback and sorry for my slow reply.

I looked into this some more and attached a updated patch with a more complete test. It also covers a crash now that happens when there is a symlink cycle in the tar and on disk. 

My fix is to remove existing links before unpack and replace them with the link in the tar. This is what gnu tar is also doing (according to http://www.gnu.org/software/tar/manual/html_node/Dealing-with-Old-Files.html). However this seems to be a behavior change of what the tarfile module has traditionally been done so feel free to reject it, I'm open to alternative ideas of course (even though I feel like having the same behavior as gnu tar is desirable).

Thanks,
 Michael