Re: BUG #16526: pg_test_fsync in v12 doesn't run in Windows

On Tue, Jul  7, 2020 at 05:25:49PM +0900, Michael Paquier wrote:
> So, I have been looking at that again.  And, I am not completely sure
> why the combination of FILE_FLAG_NO_BUFFERING and _setmode(O_TEXT)
> would cause this failure, but I suspect that this is caused by the
> fact that CRLF gets changed into single LF characters on input (input
> buffer uses random data), causing the size of what's expected to be
> written to not match with what is actually written.  An additional
> factor is visibly our wrapper safe-concurrent wrapper pgwin32_open().
> 
> It seems to me that it would be a better idea to just use the binary
> mode for all the open() calls in pg_test_fsync in the long run, which
> is what the attached patch does as there is no control on the data
> written.  This way, we avoid any translation that may happen during
> the write.  Any thoughts?

Well, pg_test_fsync is testing binary writes, so using TEXT for the
files might add unwanted overhead, so I think binary is the best
approach.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

  The usefulness of a cup is in its emptiness, Bruce Lee