Re: lynx-dev 2.8.1 fails under cron (with ncurses & nsl-fork)

[Bela Lubkin]

Tom Dickey wrote:

> ok - it is not an ncurses bug, but a small error in Bela's nsl-fork logic that
> happens to be ifdef'd to exclude slang (he neglected to check that
> stdin is a tty in that chunk).  I've a fix, am about 1/3 through integrating
> other patches.  fyi:
> 
> > diff -u HTTCP.c.orig HTTCP.c
> --- HTTCP.c.orig        Wed Nov 18 14:45:34 1998
> +++ HTTCP.c     Tue Dec  1 21:41:30 1998
> @@ -539,7 +539,7 @@
>                 **  selectable!  /dev/null isn't, on some systems, which
>                 **  makes some useful Lynx invocations fail.  -BL
>                 */
> -               if (ok_to_select_stdin == -1) {
> +               if ((ok_to_select_stdin == -1) && isatty(fileno(stdin))) {
>                     timeout.tv_sec = 0;
>                     timeout.tv_usec = 0;
>                     FD_SET(0, &readfds);    /* stdin -BL */
> @@ -548,7 +548,7 @@
>                     else ok_to_select_stdin = 0;
>                     FD_ZERO(&readfds);
>                 }
> -               if (ok_to_select_stdin) FD_SET(0, &readfds);
> +               if (ok_to_select_stdin == 1) FD_SET(0, &readfds);
>  #endif /* USE_SLANG */
>                 timeout.tv_sec = 1;
>                 timeout.tv_usec = 0;

What you really mean here is to set ok_to_select_stdin to 0 if not
isatty.  I had resisted that because I thought there might be some
useful case where stdin wasn't a tty, but you might still want to be
able to interrupt with it; but now, thinking about that, it seems like a
lot of nonsense.  So use this instead.  It's simpler, less likely to
break anywhere.

Also, BTW, I don't know that this *wouldn't* work with slang.  I just
don't have a test setup with slang.  If someone who uses slang would
like to try it without that particular #ifdef USE_SLANG, we can probably
remove the #ifdef.  (Maybe John E. Davis can comment...)

>Bela<

*** HTTCP.c.orig        Wed Nov 18 11:23:55 1998
--- HTTCP.c     Wed Dec  2 15:21:27 1998
***************
*** 456,458 ****
            int child_exited = 0;
-           int ok_to_select_stdin = -1;
  
--- 456,457 ----
***************
*** 536,552 ****
                **  users must live with up-to-1s timeout.  -BL
-               **
-               **  Whoops -- we need to make sure stdin is actually
-               **  selectable!  /dev/null isn't, on some systems, which
-               **  makes some useful Lynx invocations fail.  -BL
                */
!               if (ok_to_select_stdin == -1) {
!                   timeout.tv_sec = 0;
!                   timeout.tv_usec = 0;
!                   FD_SET(0, &readfds);    /* stdin -BL */
!                   selret = select(1, &readfds, NULL, NULL, &timeout);
!                   if (selret >= 0) ok_to_select_stdin = 1;
!                   else ok_to_select_stdin = 0;
!                   FD_ZERO(&readfds);
!               }
!               if (ok_to_select_stdin) FD_SET(0, &readfds);
  #endif /* USE_SLANG */
--- 535,538 ----
                **  users must live with up-to-1s timeout.  -BL
                */
!               if (isatty(fileno(stdin))) FD_SET(fileno(stdin), &readfds);
  #endif /* USE_SLANG */