I've tried to review the patch, but I'm not sure what is changed. Based on the summary, I did the following:
1. Take a tar.gz tarball and rename it test.tar.xz
2. Try "$ tar xf test<TAB><TAB>"
This autocompleted to test.tar.xz as expected with the current version of bash-completion in Natty.
I also noticed that the change as committed to the upstream source is slightly different. It omits the "-X" argument to compgen. I would guess the patch against the ubuntu package should be updated for this change as well.
I've tried to review the patch, but I'm not sure what is changed. Based on the summary, I did the following:
1. Take a tar.gz tarball and rename it test.tar.xz
2. Try "$ tar xf test<TAB><TAB>"
This autocompleted to test.tar.xz as expected with the current version of bash-completion in Natty.
I also noticed that the change as committed to the upstream source is slightly different. It omits the "-X" argument to compgen. I would guess the patch against the ubuntu package should be updated for this change as well.