Re: Failure of resizeterm() causes subsequent call with stdscr to crash

[Bill Gray]

On 9/25/24 08:29, Peter Bierma wrote:> This was reported downstream as a 
bug in Python's curses module. See the
> issue there: https://github.com/python/cpython/issues/120378 
> <https://github.com/python/cpython/issues/120378>
>
> It seems that calling resizeterm() with some ridiculous resolution 
> (35000x1 in the CPython issue) causes stdscr to break (i.e., a crash). A 
> small reproducer:
>
>      #include <curses.h> // or ncurses.h
>
>      int
>      main(void)
>      {
>          initscr();
>          if (resizeterm(35000, 1) < 0) {
>              puts("resizeterm() failed, trying to reset");
>          }
>          wrefresh(stdscr); // Segfault!
>          return 0;
>      }

   The limit appears to be 32767.  32768 (which,  as a signed short, 
is really -32768) fails.  Similarly,

win = newwin( 32767, 0, 0, 0);

   returns a non-NULL pointer.  Go up by one,  and win == NULL.

   I can't come up with a reason why you'd have such a large window. 
But then again,  I also can't come up with a reason why it should fail.

-- Bill

> At first I thought this was an issue with stdscr getting freed, but 
> manually resetting it with initscr() still causes use of stdscr to 
> crash. Any ideas?
>
> Best regards,
> Peter Bierma