lzma compression/decompression in bsdtar/libarchive?

[bf]

> lzma files in the current form are a major PITA. The format doesn't have
> a proper header and therefore is not really autodetectable.

I'm sure that the format has some shortcomings; however, it is being widely
used, and so it would be helpful to be able to deal with such files.  To be
clear: I'm not arguing the merits of any particular *file format*, although
I have mentioned a couple of the ones that are now used for lzma-compressed
data. (There is no reason why we couldn't define and promote our own file
format to contain such data, if we thought that the existing ones didn't
meet our needs.)  What I am arguing for is to have the capability to use
lzma *compression* when it would be to our advantage.

Regards,
        b.