[PATCH] glob: Simplify the interface for the GLOB_ALTDIRFUNC callback gl_readdir

[Roland McGrath]

This is a potentially breaking ABI and API change.  The documentation does
not say anything specific about what the gl_readdir function's protocol is.
It just says "an alternative implementation of readdir".  The way I'd read
that, and the reality of the status quo ante, is that a trivial wrapper
around readdir will behave identically to not using GLOB_ALTDIRFUNC at all.
That means that d_ino==0 results must be ignored.

IMHO this means we need symbol versioning to make a change to the treatment
of d_ino.

It's a sufficiently conservative change to start ignoring d_namlen,
so you could do that separately.


Thanks,
Roland