fix race condition between sigwinch and sigchld - scroll - scrollbackbuffer program for st

git clone git://git.suckless.org/scroll

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---

commit 1dbf2dce08892df710645ddbd2ce12759ec95078

parent 58c58743d8f391ef0e4776fc46d92c824795d162

Author: Jan Klemkow 

Date:   Thu, 30 Apr 2020 22:12:50 +0200

fix race condition between sigwinch and sigchld

sigwinch died if it tries to set the window size
to a file descriptor of an exited child.  Thus,
we just ignore this error in that situation.

Diffstat:
  M scroll.c                            |       5 ++++-

1 file changed, 4 insertions(+), 1 deletion(-)
---

diff --git a/scroll.c b/scroll.c

@@ -96,8 +96,11 @@ sigwinch(int sig)
 
         if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == -1)
                 die("ioctl:");
-        if (ioctl(mfd, TIOCSWINSZ, &ws) == -1)
+        if (ioctl(mfd, TIOCSWINSZ, &ws) == -1) {
+                if (errno == EBADF)        /* child already exited */
+                        return;
                 die("ioctl:");
+        }
         kill(-child, SIGWINCH);
         doredraw = true;
 }