7zip vs. lha

[chris]

I didn't.  I made the archive with lha.
But I wanted to see if the archive survived the transfer thru my ancient Ethernet card to my bgcPC so I test extracted the files using 7zip.

On Windows I only trust LhA NT to extract Amiga LhA archives correctly.

do not use 7zip or zip or ace to backup amiga files
they are not specially designed for the amiga files
when you decrunch that compressed files you can lost comments and the correct date of the original files...also you can have problems with empty dirs and prblems with protection
use lha or lzx

Agree with that.  Amiga 7za needs some serious work to support Amiga-style paths, ptotection bits and file comments whilst still maintaining compatibility.

It would probably be easier to add better compression schemes to LhA (such as LZMA2, or at least higher LZW variants that our LhA doesn't support but others do)

[chris]

I have tried the xad module for 7z off of Aminet and it was VERY buggy and didn't recognize the 7z files I tried.

I find that incredibly surprising, my inbox would be inundated with emails if that was the case.

To recognise files it simply looks for the file header "7z" (and the next few bytes, whatever they are).  This is the official header for 7-Zip files, so if it isn't recognising them your files are probably the issue.

I'm aware of potential stack overruns but these won't occur until it hits PPMd decompression.  Most 7-Zips use LZMA or LZMA2.

[chris]

@chris
xadUnFile is back to crashing with your xad_7z installed again. I consistently get "Exception 6: chk instruction" with PC=$2e. I tried using MuForce but the system freezes when I do with no hits before it does. xad_7z worked the first time I installed it and rebooted but crashes now with the same archive. There's plenty of stack for xadUnFile according to Scout.

I used BDebug to catch a crashed task and it looks like there is a branch to PC=8 first. Back tracking from the last stack entry, I find xad_xfd+$3f0 doing a jsr to exec/OpenLibrary() opening xfdmaster.library version $26. I don't see any problems with the xad_xfd code. Removing xad_7z from Libs:xad/ stops the crashes. I'm surprised no one else has reported this problem. Versions used are...

xadmaster.library 12.1
xad_7z 2.4
xad_xfd 1.1
xadUnFile 1.25

My setup is a 3000T with CSMK3 68060 using AmigaOS 3.9.

xad_xfd 68k version definitely doesn't work, remove it and see if that also stops xad_7z crashing.