Built-in archiver takes priority over custom archiver for a different format.

[Fothsid]

Title self-explanatory.

I have a custom archiver for AFS files, but I have to mount archives with both .AFS and .DAT extensions. I register it with PHYSFS_registerArchiver just for the .AFS extension. For .DAT files, the POD archiver seems to take priority for the files I mount.

Looking at the source code, the validity checks before claiming the archive seem very loose:

BAIL_IF_ERRPASS(!readui32(io, &dummy), 0);
BAIL_IF_ERRPASS(!__PHYSFS_readAll(io, description, 80), NULL);
if ((description[0] == 0) || (description[79] != 0)) // Check if we're lacking a description or last char isn't a null terminator.
    return NULL;

io->seek(io, 0);

*claimed = 1;

Currently I'm mitigating this in my project by manually disabling the POD archiver.

Usually I'd just submit a PR for this kind of thing, but I'm not sure what is the good solution here. Personally, I would've preferred an API change to be able to either append or prepend to the archiver list, just like how it is possible with search paths when mounting.