support for unpackver=20?

[campbellr]

I have a bunch of rar files that are (apparently) RAR4. Most of them fail to extract with rardecode with a unsupported decoder version. Adding some print statements shows that unpackver is 20.

Is there any particular reason that it is unsupported (other than lack of time, say)?

Is expanding the set of supported versions/formats something that is in the pipeline?

If there are no huge blockers, I may take a stab at adding support (although at this point i know nothing about the rar format(s) except the little i've gleaned from scanning through this codebase and the c++ unrar codebase)

[nwaples]

I just had no files to test with. Current winrar, etc won't create the old versions.

I could have a go at it. I had a quick look, and since its the predecessor to 29 I could reuse/copy a bunch of stuff from it. It looks quite familiar. I might have to rework a few small things, as I couldn't see any explicit end of block marker in the format.

Having a test file would make it easier.

[campbellr]

That would be great. I can upload the rar file that was failing somewhere and attach a link here if you want.

[nwaples]

Sure, that would be good.

[nwaples]

I've added some code in the experimental branch for unpackver 20. Its untested, but if you are very lucky maybe it will work.

[davidnewhall]

No idea what version these files are, but this library will not extract them. Found them in some 10+ year old torrents. Hoping you can make it work! 🤞 I put both RAR files inside a zip file so GitHub would accept them.

• b2b_gui01b.rar produces rardecode: unsupported decoder version
• dc_selfboot_kit.rar produces rardecode: bad header crc

Archive.zip