Additional checks to make sure we don't close /dev/tty by mistake.

When flushing, sleep in select as long as we have buffers that need
to be written out.

diff --git a/src/script.c b/src/script.c
index 47131a3e8e99dbf373ee1efde66eaa41e468c582..21ecff6ccf82675009087febae55c9d3e267a7ad 100644 (file)
--- a/src/script.c
+++ b/src/script.c
@@ -433,7 +433,8 @@ perform_io(struct io_buffer *iobufs, fd_set *fdsr, fd_set *fdsw)
                    break;
            } else if (n == 0) {
                /* got EOF */
-               close(iob->rfd);
+               if (iob->rfd != script_fds[SFD_USERTTY])
+                   close(iob->rfd);
                iob->rfd = -1;
            } else {
                if (!iob->action(iob->buf + iob->len, n))
@@ -450,10 +451,12 @@ perform_io(struct io_buffer *iobufs, fd_set *fdsr, fd_set *fdsw)
                if (errno == EPIPE) {
                    /* other end of pipe closed */
                    if (iob->rfd != -1) {
-                       close(iob->rfd);
+                       if (iob->rfd != script_fds[SFD_USERTTY])
+                           close(iob->rfd);
                        iob->rfd = -1;
                    }
-                   close(iob->wfd);
+                   if (iob->wfd != script_fds[SFD_USERTTY])
+                       close(iob->wfd);
                    iob->wfd = -1;
                    continue;
                }
@@ -1173,7 +1176,7 @@ flush_output(struct io_buffer *iobufs)
     struct io_buffer *iob;
     struct timeval tv;
     fd_set *fdsr, *fdsw;
-    int nready, maxfd = -1;
+    int nready, nwriters, maxfd = -1;
 
     /* Determine maxfd */
     for (iob = iobufs; iob; iob = iob->next) {
@@ -1189,9 +1192,10 @@ flush_output(struct io_buffer *iobufs)
        zero_bytes(fdsw, howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask));
        zero_bytes(fdsr, howmany(maxfd + 1, NFDBITS) * sizeof(fd_mask));
 
+       nwriters = 0;
        for (iob = iobufs; iob; iob = iob->next) {
            /* Don't read from /dev/tty while flushing. */
-           if (iob->rfd == script_fds[SFD_USERTTY])
+           if (script_fds[SFD_USERTTY] != -1 && iob->rfd == script_fds[SFD_USERTTY])
                continue;
            if (iob->rfd == -1 && iob->wfd == -1)
                continue;
@@ -1209,15 +1213,17 @@ flush_output(struct io_buffer *iobufs)
                    FD_SET(iob->rfd, fdsr);
            }
            if (iob->wfd != -1) {
-               if (iob->len > iob->off)
+               if (iob->len > iob->off) {
+                   nwriters++;
                    FD_SET(iob->wfd, fdsw);
+               }
            }
        }
 
-       /* Effect a poll (no sleeping in select) */
+       /* Don't sleep in select if there are no buffers that need writing. */
        tv.tv_sec = 0;
        tv.tv_usec = 0;
-       nready = select(maxfd + 1, fdsr, fdsw, NULL, &tv);
+       nready = select(maxfd + 1, fdsr, fdsw, NULL, nwriters ? NULL : &tv);
        if (nready <= 0) {
            if (nready == 0)
                break; /* all I/O flushed */