[PATCH] Cygwin: pipe: Suppress unnecessary set_pipe_non_blocking() call.

[Takashi Yano]

- Call set_pipe_non_blocking(false) only if the pipe will be really
  inherited to non-cygwin process.
---
 winsup/cygwin/spawn.cc | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/winsup/cygwin/spawn.cc b/winsup/cygwin/spawn.cc
index 6b2026776..e160fa3bb 100644
--- a/winsup/cygwin/spawn.cc
+++ b/winsup/cygwin/spawn.cc
@@ -648,8 +648,9 @@ child_info_spawn::worker (const char *prog_arg, const char 
*const *argv,
 
       if (!iscygwin ())
        {
+         int fd;
          cfd.rewind ();
-         while (cfd.next () >= 0)
+         while ((fd = cfd.next ()) >= 0)
            if (cfd->get_major () == DEV_PTYS_MAJOR)
              {
                fhandler_pty_slave *ptys =
@@ -657,13 +658,15 @@ child_info_spawn::worker (const char *prog_arg, const 
char *const *argv,
                ptys->create_invisible_console ();
                ptys->setup_locale ();
              }
-           else if (cfd->get_dev () == FH_PIPEW)
+           else if (cfd->get_dev () == FH_PIPEW
+                    && (fd == (in__stdout < 0 ? 1 : in__stdout) || fd == 2))
              {
                fhandler_pipe *pipe = (fhandler_pipe *)(fhandler_base *) cfd;
                pipe->close_query_handle ();
                pipe->set_pipe_non_blocking (false);
              }
-           else if (cfd->get_dev () == FH_PIPER)
+           else if (cfd->get_dev () == FH_PIPER
+                    && fd == (in__stdin < 0 ? 0 : in__stdin))
              {
                fhandler_pipe *pipe = (fhandler_pipe *)(fhandler_base *) cfd;
                pipe->set_pipe_non_blocking (false);
-- 
2.33.0