Joachim Schmitz wrote:
Joachim Schmitz wrote:
If poll() is used as a milli-second sleep, like in help.c, by passing
a NULL in the 1st and a 0 in the 2nd arg, it exits with EFAULT.

As per Paolo Bonzini, the original author, this is a bug and to be
fixed like in this commit, which is not to exit if the 2nd arg is 0.

Signed-off-by: Joachim Schmitz <>
compat/win32/poll.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/compat/win32/poll.c b/compat/win32/poll.c
index 403eaa7..9e7a25c 100644
--- a/compat/win32/poll.c
+++ b/compat/win32/poll.c
@@ -349,7 +349,7 @@ poll (struct pollfd *pfd, nfds_t nfd, int
  /* EFAULT is not necessary to implement, but let's do it in the
     simplest case. */
-  if (!pfd)
+  if (!pfd && nfd)
      errno = EFAULT;
      return -1;

Actually this one is not needed for win32 (nor does win32 suffer from
a similar bug), so should probably better get added after patch 2/2
(or as part of it), the move to compat/poll/.

It just got added that was to gnulib, with a commit message of:

don't exit early if NULL is the 1st arg to poll(),
but nfd is 0.  In that case poll should behave like select.

Bye, Jojo

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