script: exit if reading from pseudo-tty errors out (do not loop)

function                                             old     new   delta
script_main                                          991     966     -25

1 files changed, 16 insertions, 19 deletions

diff --git a/util-linux/script.c b/util-linux/script.c
index 5d6f4d924..63d3039d3 100644
--- a/util-linux/script.c
+++ b/util-linux/script.c
@@ -99,13 +99,12 @@ int script_main(int argc ATTRIBUTE_UNUSED, char **argv)
                 /* parent */
 #define buf bb_common_bufsiz1
                 struct pollfd pfd[2];
-                struct pollfd *ppfd = pfd;
                 int outfd, count, loop;
 
                 outfd = xopen(fname, mode);
-                pfd[0].fd = 0;
+                pfd[0].fd = pty;
                 pfd[0].events = POLLIN;
-                pfd[1].fd = pty;
+                pfd[1].fd = 0;
                 pfd[1].events = POLLIN;
                 ndelay_on(pty); /* this descriptor is not shared, can do this */
                 /* ndelay_on(0); - NO, stdin can be shared! Pity :( */
@@ -115,29 +114,17 @@ int script_main(int argc ATTRIBUTE_UNUSED, char **argv)
                 /* TODO: don't use full_write's, use proper write buffering */
                 while (fd_count) {
                         /* not safe_poll! we want SIGCHLD to EINTR poll */
-                        if (poll(ppfd, fd_count, -1) < 0 && errno != EINTR) {
+                        if (poll(pfd, fd_count, -1) < 0 && errno != EINTR) {
                                 /* If child exits too quickly, we may get EIO:
                                  * for example, try "script -c true" */
                                 break;
                         }
                         if (pfd[0].revents) {
-                                count = safe_read(0, buf, sizeof(buf));
-                                if (count <= 0) {
-                                        /* err/eof: don't read anymore */
-                                        pfd[0].revents = 0;
-                                        ppfd++;
-                                        fd_count--;
-                                } else {
-                                        full_write(pty, buf, count);
-                                }
-                        }
-                        if (pfd[1].revents) {
                                 errno = 0;
                                 count = safe_read(pty, buf, sizeof(buf));
                                 if (count <= 0 && errno != EAGAIN) {
-                                        /* err/eof: don't read anymore */
-                                        pfd[1].revents = 0;
-                                        fd_count--;
+                                        /* err/eof from pty: exit */
+                                        goto restore;
                                 }
                                 if (count > 0) {
                                         full_write(1, buf, count);
@@ -147,6 +134,16 @@ int script_main(int argc ATTRIBUTE_UNUSED, char **argv)
                                         }
                                 }
                         }
+                        if (pfd[1].revents) {
+                                count = safe_read(0, buf, sizeof(buf));
+                                if (count <= 0) {
+                                        /* err/eof from stdin: don't read stdin anymore */
+                                        pfd[1].revents = 0;
+                                        fd_count--;
+                                } else {
+                                        full_write(pty, buf, count);
+                                }
+                        }
                 }
                 /* If loop was exited because SIGCHLD handler set fd_count to 0,
                  * there still can be some buffered output. But not loop forever:
@@ -161,7 +158,7 @@ int script_main(int argc ATTRIBUTE_UNUSED, char **argv)
                         full_write(1, buf, count);
                         full_write(outfd, buf, count);
                 }
-
+ restore:
                 if (attr_ok == 0)
                         tcsetattr(0, TCSAFLUSH, &tt);
                 if (!(opt & 8)) /* not -q */