Re: stat() vs ERROR_DELETE_PENDING, round N + 1

On Fri, Sep 10, 2021 at 5:04 PM Thomas Munro <thomas.munro@gmail.com> wrote:
> On Tue, Sep 7, 2021 at 7:00 PM Alexander Lakhin <exclusion@gmail.com> wrote:
> > 07.09.2021 09:05, Michael Paquier wrote:
> > > On Tue, Sep 07, 2021 at 09:00:01AM +0300, Alexander Lakhin wrote:
> > >> The new approach looks very promising. Knowing that the file is really
> > >> in the DELETE_PENDING state simplifies a lot.
> > >> I've tested the patch v2_0001_Check... with my demo tests [1] and [2],
> > >> and it definitely works.

Since our handling of that stuff never really worked the way we wanted
(or if it did, then Windows' behaviour changed, possibly well over a
decade ago, from what I could dig up), this isn't an open item
candidate for 14 after all, it's a pre-existing condition.  So I
propose to push this fix to master only soon, and then let it stew
there for a little while to see how the buildfarm Windows variants and
the Windows hacker community testing on master react.  If it looks
good, we can back-patch it a bit later, perhaps some more convenient
time WRT the release.

I added a CF entry to see if anyone else wants to review it and get CI.

One small detail I'd like to draw attention to is this bit, which
differs slightly from the [non-working] previous attempts by mapping
to two different errors:

+         * If there's no O_CREAT flag, then we'll pretend the file is
+         * invisible.  With O_CREAT, we have no choice but to report that
+         * there's a file in the way (which wouldn't happen on Unix).

...

+            if (fileFlags & O_CREAT)
+                err = ERROR_FILE_EXISTS;
+            else
+                err = ERROR_FILE_NOT_FOUND;