[PATCH 5 of 5] posix: give checklink a fast path that cache the check file and is read only

[Danek Duvall]

Danek Duvall wrote:

> I tried adding "delete=(cachedir is None)" (or the equivalent) to the
> NamedTemporaryFile call, and that cleared up all the cp -r errors, but left
> behind three tests failing due to the files left behind.  At least two of
> them are straightforward to fix, I think, since they're just the output of
> ls commands, but the ones in test-hardlinks.t I'm not so sure about.

I'm wondering if util.copyfiles() needs to be smarter about copying/linking
symlinks.  But I could just add "| grep -v checklink" to those tests and
sweep it under the rug.

Danek