untar will be interruptted if change directory

[billiebub]

normally, when you extract tarballs, TC will first copy the extract files to it's _tc directory under temp. When you start extracting the files, TC simply copies the files from the _tc directory. If you change the directory where the tarball was, TC will automatically delete the extracted tarball files under the _tc directory and unpacking will stop.

I suggest to warn the user that the unpacking will be lost or something around these lines or better off change the directory without affecting the _tc directory. TC should only clean up once the unpacking is finished or interrupted by the user.