tags 901952 +help thanks I question whether this bug is really release-critical, since the only cases of it I've heard about so far are the two instances pointed to in this bug log where pristine-tar is being used across distributions and versions... I've not seen the behavior in any of my own packaging work.
However, if someone wants to work out a way to patch current tar such that it mimics the old behavior when necessary to unpack an older tarball without breaking anything else, I'd be happy to merge such a patch. I mean something like what was done to fix #897653. Bdale