On Tue, Nov 08, 2016 at 05:22:52PM -0800, Junio C Hamano wrote: > Jeff King <peff@xxxxxxxx> writes: > > > Probably converting "rename(from, to)" to first check "access(to, > > W_OK)". That's racy, but it's the best we could do. > > Hmph, if these (possibly problematic) callers are all following the > usual "lock, write to temp, rename" pattern, perhaps the lock_file() > function can have access(path, W_OK) check before it returns a > tempfile that has been successfully opened? Yeah, that is a lot friendlier, as it prevents the caller from doing work (which may even involve the user typing things!) when it is clear that we would fail the final step anyway. -Peff