fix: process the final pipe input event before closing (#8)

In the event that poll returned both POLLIN and POLLHUP in a single pass we
were mistakenly closing the file descriptor without processing that final
input. This was addressed by changing the condition for ending the loop.

Also expanded the midline-flush test to run 10 times because that's what
was most effective in demonstrating the problem.

t3.c

@@ -640,7 +640,7 @@ int main(int argc, char *argv[]) {
                pfds[0].revents & POLLIN, pfds[0].revents & POLLPRI,
                pfds[0].revents & POLLOUT, pfds[0].revents & POLLERR,
                pfds[0].revents & POLLHUP, pfds[0].revents & POLLNVAL);
-        if ((pfds[0].revents & POLLIN) && !(pfds[0].revents & POLLHUP)) {
+        if (pfds[0].revents & POLLIN) {
           _debug(2, "detected input on stdout_msg_pipe[0]");
           struct payload *msg_payload = malloc(sizeof(struct payload));
           if (read(stdout_msg_pipe[0], msg_payload, sizeof(struct payload)) >
@@ -659,7 +659,7 @@ int main(int argc, char *argv[]) {
           num_open_fds--;
           waitpid(stdout_worker, NULL, WNOHANG);
         }
-        if ((pfds[1].revents & POLLIN) && !(pfds[1].revents & POLLHUP)) {
+        if (pfds[1].revents & POLLIN) {
           _debug(2, "detected input on stderr_msg_pipe[0]");
           struct payload *msg_payload = malloc(sizeof(struct payload));
           if (read(stderr_msg_pipe[0], msg_payload, sizeof(struct payload)) >

tests/midline-flush.args

@@ -1 +1 @@
--- tests/midline-flush
+-- sh -c 'for i in `seq 1 10`; do tests/midline-flush; done'

tests/midline-flush.err

@@ -1 +1,10 @@
 Hello, stderr! Goodbye, stderr!
+Hello, stderr! Goodbye, stderr!
+Hello, stderr! Goodbye, stderr!
+Hello, stderr! Goodbye, stderr!
+Hello, stderr! Goodbye, stderr!
+Hello, stderr! Goodbye, stderr!
+Hello, stderr! Goodbye, stderr!
+Hello, stderr! Goodbye, stderr!
+Hello, stderr! Goodbye, stderr!
+Hello, stderr! Goodbye, stderr!

tests/midline-flush.log

@@ -1,2 +1,20 @@
 Hello, stderr! Goodbye, stderr!
 Hello, stdout! Goodbye, stdout!
+Hello, stderr! Goodbye, stderr!
+Hello, stdout! Goodbye, stdout!
+Hello, stderr! Goodbye, stderr!
+Hello, stdout! Goodbye, stdout!
+Hello, stderr! Goodbye, stderr!
+Hello, stdout! Goodbye, stdout!
+Hello, stderr! Goodbye, stderr!
+Hello, stdout! Goodbye, stdout!
+Hello, stderr! Goodbye, stderr!
+Hello, stdout! Goodbye, stdout!
+Hello, stderr! Goodbye, stderr!
+Hello, stdout! Goodbye, stdout!
+Hello, stderr! Goodbye, stderr!
+Hello, stdout! Goodbye, stdout!
+Hello, stderr! Goodbye, stderr!
+Hello, stdout! Goodbye, stdout!
+Hello, stderr! Goodbye, stderr!
+Hello, stdout! Goodbye, stdout!

tests/midline-flush.out

@@ -1 +1,10 @@
 Hello, stdout! Goodbye, stdout!
+Hello, stdout! Goodbye, stdout!
+Hello, stdout! Goodbye, stdout!
+Hello, stdout! Goodbye, stdout!
+Hello, stdout! Goodbye, stdout!
+Hello, stdout! Goodbye, stdout!
+Hello, stdout! Goodbye, stdout!
+Hello, stdout! Goodbye, stdout!
+Hello, stdout! Goodbye, stdout!
+Hello, stdout! Goodbye, stdout!