Re: delwin() and deleting windows with subwindows

[Thomas Dickey]

On Sun, Aug 14, 2022 at 03:14:59PM -0400, Bill Gray wrote:
> On 8/13/22 19:20, Thomas Dickey wrote:
> > On Thu, Aug 11, 2022 at 10:31:43PM -0400, Bill Gray wrote:
> > >     I was tempted to keep recursive deletion (the code was all written and
> > > tested),  but I've chickened out.
> > 
> > good idea :-)
> 
>    (Hangs head) Yeah,  I got a little carried away when I pushed the
> recursive-deletion version.

no problem (I should have checked the test program before updating
the manpage -- memory isn't good on ~20 year old changes).
 
> > Today I made a modified test-program which made it simple(r) to fix that.
> 
>    The PDCurses makefiles can build a subset of ncurses test programs;
> PDCursesMod has a larger subset,  to which I've added test_delwin.

sounds good ...
 
> > fwiw, NetBSD curses hangs (infinite loop) on the first delwin in your
> > example, while Solaris dumps core on the last delwin.
> 
>    Well,  that's interesting.  It sounds as if trying to delete parent
> windows should be strongly discouraged.  I can't think of a case where you

at least it's not done often enough for someone to report a problem with
NetBSD ;-)

> would legitimately try to delete a parent window anyway.  If you try,  you
> probably have a bug in your code.  (Similarly if you try to delwin() a
> window twice or delwin() a NULL pointer.)
> 
>    I've modified PDCursesMod so that in debug builds,  deleting a parent
> window triggers an assert().  Better that,  I think,  than letting things
> proceed and probably crash later on.
> 
> -- Bill

-- 
Thomas E. Dickey <dickey@invisible-island.net>
https://invisible-island.net
ftp://ftp.invisible-island.net

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