Incorrectly detecting rar support for 7z

[hunkyburrito]

I was getting the same error as #149 after a system update where p7zip was replaced with the upstream 7zip package on archlinux. After looking through the code a bit, I found that util.p7zip_supports_rar() was looking for rar codecs that it will not find on my system, preventing me from extracting rar files even though they are supported on later 7zip versions according to the 7-zip FAQ.

Why can't 7-Zip open some RAR archives?

7-Zip 9.20 supports RAR 2/3/4 formats only and doesn't support RAR5 archives. But latest versions of 7-Zip supports RAR5 archives.

Linux previously needed the p7zip package obviously, but with the native linux release since version 21.0.1 alpha, there is no longer a need for p7zip, meaning there could be rar support built-in without those codecs.

Maybe there can be some kind of version check in addition? Or alternatively a more advanced solution that parses the output from 7z i to find supported formats.

Edit: I'm specifically talking about the python patoolib module as a program I use has implemented that for extraction.