poll tests: Avoid test failure on AIX.

* tests/test-poll.c (test_pipe): Disable the "expecting POLLHUP after
shutdown" test on AIX.
* doc/posix-functions/poll.texi: Mention the AIX bug.

3 files changed, 16 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index f2d18546e0..bf98e8005c 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,12 @@
 2020-12-31  Bruno Haible  <bruno@clisp.org>
 
+	poll tests: Avoid test failure on AIX.
+	* tests/test-poll.c (test_pipe): Disable the "expecting POLLHUP after
+	shutdown" test on AIX.
+	* doc/posix-functions/poll.texi: Mention the AIX bug.
+
+2020-12-31  Bruno Haible  <bruno@clisp.org>
+
 	poll tests: Avoid test failure on BSD and Solaris systems.
 	* tests/test-poll.c (test_accept_first, test_socket_pair): Disable the
 	"expecting POLLHUP after shutdown" test on all platforms except Linux.
diff --git a/doc/posix-functions/poll.texi b/doc/posix-functions/poll.texi
index a04d3b8b18..c1efe87ad9 100644
--- a/doc/posix-functions/poll.texi
+++ b/doc/posix-functions/poll.texi
@@ -23,8 +23,8 @@ Portability problems not fixed by Gnulib:
 Under Windows, when passing a pipe, Gnulib's @code{poll} replacement might
 return 0 even before the timeout has passed.  Programs using it with pipes can
 thus busy wait.
-
 @item
-Under HP NonStop, file descriptors other than sockets do not support
-POLLHUP; they will return a "readable" status instead.
+On some platforms, file descriptors other than sockets do not support
+POLLHUP; they will return a "readable" or "writable" status instead:
+AIX 7.2, HP NonStop.
 @end itemize
diff --git a/tests/test-poll.c b/tests/test-poll.c
index 05248d8f8f..5105620ab0 100644
--- a/tests/test-poll.c
+++ b/tests/test-poll.c
@@ -362,8 +362,13 @@ test_pipe (void)
   ASSERT (pipe (fd) >= 0);
   test_pair (fd[0], fd[1]);
   close (fd[0]);
-  if ((poll1_wait (fd[1], POLLIN | POLLOUT) & (POLLHUP | POLLERR)) == 0)
+  int revents = poll1_wait (fd[1], POLLIN | POLLOUT);
+#if !defined _AIX
+  if ((revents & (POLLHUP | POLLERR)) == 0)
     failed ("expecting POLLHUP after shutdown");
+#else
+  (void) revents;
+#endif
 
   close (fd[1]);
 }