xz, lzma compression don't work

[mharvey-jt]

for xz, lzma but not gzip compression types, the output rpms are apparently corrupt:

rpmsample | rpm2cpio | cpio -t
cpio: premature end of archive

tested with rpm2cpio from rhel7 and upstream 4.16.1.3

[jarondl]

@djgilcrease - as the contributor of xz and lzma to rpmpack (#19) do you want to take a stab at this?

[djgilcrease]

Sure, will take a look at it today.

[djgilcrease]

this appears to be an issue specific to rhel7 I tested this with Fedora34, centos 8, centos 7 and I am not seeing this issue.

[djgilcrease]

I would guess that rhel7 only really supports gzip based on https://docs.fedoraproject.org/ro/Fedora_Draft_Documentation/0.1/html/RPM_Guide/ch-package-structure.html#id674921

According to the LSB standards, the RPMTAG_PAYLOADFORMAT must always be cpio. The RPMTAG_PAYLOADCOMPRESSOR must be gzip. The RPMTAG_PAYLOADFLAGS must always be 9.

[mharvey-jt]

Ok, makes sense. Thanks for investigating, let's close this now.

[jarondl]

Thank you @mharvey-jt for reporting, and thank you so much @djgilcrease for finding the reason!

Without doubt, rpm is the gift that keeps on giving. I think we'll treat this closed bug as documentation, if anyone else complains we may need to put something in the readme as well.