win32: more problems with stream i/o and MSVCRT

These commands:

   cut --wrong-opt 2>&1
   echo $(cut --wrong-opt 2>&1)

resulted in different output.  In the first case the message about
the invalid option appeared before the usage message; in the second
after.

The command

   uname --wrong-opt 1>&- 2>&-

displayed the error message even though both output streams were
closed.

These issues appear to be related to those previously fixed by
commits 4be93f32f and f192e6539:

- They involve the interaction between shell redirection and stream
  input/output.

- UCRT builds aren't affected.

Apply two workarounds:

- When the file descriptor associated with stderr is redirected
  remind stderr it should be unbuffered.  (32- and 64-bit MSVCRT)

- When the file descriptor associated with any of the standard i/o
  streams is to be closed do it by closing the stream instead.
  (32-bit MSVCRT)

Adds 48-176 bytes.

(GitHub commit #472)

0 files changed, 0 insertions, 0 deletions