Re: [PATCH 3/4] copy: make backup files more reliably

[Paul Eggert]

Kamil Dudka wrote:

> Still not perfect.  Now it produces false positives with --backup=existing:

Yes, I know that, but there's no easy way to change that without introducing a 
race condition the other way. I thought it better to be conservative and reject 
the (extremely unusual) case that you mentioned, rather than make the common 
case significantly less-efficient or (worse) to lose data in some rare cases.

I suppose we could change the diagnostic to say "might destroy source" rather 
than "would destroy source". That would be more accurate.

> As for the test, could it be simplified like this?

Could be. I didn't look at the test in detail (it's now the same as before).