#include <errno.h>
#include <stdio.h>
#include <poll.h>

int main() {
        /* Test for #7859.
         * Start a process with popen and watch the pipe using poll().
         * We should get these events (preferrably in this exact order):
         * - 3 reads of the values 1, 2 and 3 from the bash script
         * - 1 end of file event (that should make the pipe readable)
         * - 1 EINTR return from poll because of the SIGCHLD signal when the child process terminates
         *
         * Currently, the EINTR return happens before the end of file event notification.
         */
        FILE* f = popen("/bin/bash -c 'for i in 1 2 3; do { echo $i; sleep 1; }; done'", "r");
        printf("f=%p\n", f);
        int fd = fileno(f);
        printf("fd=%d\n", fd);

        struct pollfd pfd;
        pfd.fd = fd;
        pfd.events = POLLIN | POLLRDBAND;

        char buffer[80];

        while (1) {
                int rv = poll(&pfd, 1, 500);
                printf("rv=%d\n", rv);
                if (rv == 0)
                        continue;
                if (rv < 0) {
                        if (errno == EINTR) {
                                puts("warning: received SIGCHLD before stream close event");
                                continue;
                        } else {
                                printf("poll returns with error %s\n", strerror(errno));
                                break;
                        }
                }
                printf("events=%08x revents=%08x\n", pfd.events, pfd.revents);
                if ((pfd.events & pfd.revents) == 0)
                        break;

                fgets(buffer, 79, f);
                printf("output: %s", buffer);
        }

        return 0;
}