commandhelper hangs indefinitely in poll() on macOS on commandtest test2
and later because POLLNVAL is returned on revents for input file
descriptor opened from /dev/null, i.e this hangs:
$ tests/commandhelper < /dev/null
BEGIN STDOUT
BEGIN STDERR
^C
But it works fine with regular stdin:
$ tests/commandhelper <<< test
BEGIN STDOUT
BEGIN STDERR
test
test
END STDOUT
END STDERR
The issue is mentioned in poll(2):
BUGS
The poll() system call currently does not support devices.
With the change all 28 cases in commandtest pass.
Signed-off-by: Roman Bolshakov <r.bolshakov(a)yadro.com>
---
Chnges since v1:
- Extract expected events into a variable (Andrea)
- Provide upstream issue # and fix a typo (Ján)
tests/commandhelper.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)
diff --git a/tests/commandhelper.c b/tests/commandhelper.c
index 7c260c4e13..ba5681b715 100644
--- a/tests/commandhelper.c
+++ b/tests/commandhelper.c
@@ -190,7 +190,17 @@ int main(int argc, char **argv) {
}
for (i = 0; i < numpollfds; i++) {
- if (fds[i].revents & (POLLIN | POLLHUP | POLLERR)) {
+ short revents = POLLIN | POLLHUP | POLLERR;
+
+# ifdef __APPLE__
+ /*
+ * poll() on /dev/null will return POLLNVAL
+ * Apple-Feedback: FB8785208
+ */
+ revents |= POLLNVAL;
+# endif
+
+ if (fds[i].revents & revents) {
fds[i].revents = 0;
got = read(fds[i].fd, buf, sizeof(buf));
--
2.28.0