Re: [PATCH] diff: do not reuse worktree files that need "clean" conversion

Jeff King [off-list ref] writes:

So I think we actually _can_ think of would_convert_to_git() as
basically free. Or as free as other efficient-lookup functions we call
like cache_name_pos().

OK.

The thought "does this tree reuse even speed things up enough to justify
its complexity" definitely crossed my mind. It's basically swapping
open/mmap for zlib inflating the content.

But I do think it helps in the "want_file" case (i.e., when we are
writing out a tempfile for an external command via prepare_temp_file()).
There it helps us omit writing a tempfile to disk entirely, including
any possible conversion.

OK.