bug#4534: assertion failure at window.c:grow_mini_window

[martin rudalics]

> I put the attached files into directory C:\temp, including the file test.el:
>
>   (setq resize-mini-windows t)
>   (setq ido-enable-flex-matching t)
>   (setq ido-max-prospects 14)
>   (ido-mode 1)
>
> Then,
>
>    emacs -Q -l c:/temp/test.el
>    C-x C-f c:/temp/testfile <TAB> 3 <TAB> 7
>
> Emacs aborts. (Note: As the failure depends on the number of lines in
> the minibuffer, tweaking `ido-max-prospects' and/or adding more files
> to the directory may be necessary to reproduce the bug.)
>
> The xassert (delta >= 0) at the start of window.c:grow_mini_window
> fails, because delta == -1. In resize_mini_window, the call to
> xdisp.c:grow_mini_window has height == 5 and WINDOW_TOTAL_LINES (w) ==
> 6.
>
>     Juanma
>
>
>
> Breakpoint 1, w32_abort () at w32fns.c:7344
> 7344      button = MessageBox (NULL,
> (gdb) bt
> #0  w32_abort () at w32fns.c:7344
> #1  0x011b929c in grow_mini_window (w=0x2f9ec00, delta=-1) at window.c:4637
> #2  0x0106d122 in resize_mini_window (w=0x2f9ec00, exact_p=0) at xdisp.c:8809
...

The following part in `resize_mini_window' doesn't strike me as very
elegant in this respect:

              if (height)
                {
                  freeze_window_starts (f, 1);
                  grow_mini_window (w, height - WINDOW_TOTAL_LINES (w));
                }

Does it cause the bug?  Just comment it out to check.

martin