Re: Problem report #28 FALSE

[Jan D.]

Thanks for trimming it down.  It is a very verbose report :-).


Stuart D. Herring wrote:
> I don't have an answer for this one, but I've trimmed the issue down for
> clarity.  We have the following if-else_if-else:
>
> > 881           if (FRAMEP (window))
> > 882             {
> > 883               f = XFRAME (window);
> > 884               xpos = 0;
> > 885               ypos = 0;
> > 886             }
> >
> > At conditional (12): "window & 7 == 4" taking false path
> >
> > 887           else if (WINDOWP (window))
> > 888             {
> > 889               CHECK_LIVE_WINDOW (window);
> > 890               f = XFRAME (WINDOW_FRAME (XWINDOW (window)));
> > 891
> > 892               xpos = WINDOW_LEFT_EDGE_X (XWINDOW (window));
> > 893               ypos = WINDOW_TOP_EDGE_Y (XWINDOW (window));
> > 894             }
> > 895           else
> > 896             /* ??? Not really clean; should be CHECK_WINDOW_OR_FRAME,
> > 897                but I don't want to make one now.  */
> >
> > At conditional (13): "window & 7 != 4" taking true path
> > At conditional (14): "0" taking false path
> >
> > 898             CHECK_WINDOW (window);
>
> f, guaranteed to be NULL before this block, is assigned in the first two
> cases but not in the third (which is tagged with a "huh?" comment).  Later
> f is used in a place Coverity claims requires non-nullity.

The else where f is not asigned (the ??? part) does a CHECK_WINDOW (window) 
where window obviously is not a window (checked in the if directly before), so 
it signals an error and exits and the call to xmenu_show never happens.

        Jan D.