bug#58028: 29.0.50; Ensures no leakage of glyph_matrix

[Po Lu]

Manuel Giraud <manuel@ledu-giraud.fr> writes:

>         eassert ((w->desired_matrix == NULL) &&
>                  (w->current_matrix != NULL));

In Emacs, we typically format the code like so:

          eassert ((w->desired_matrix == NULL)
                   && (w->current_matrix != NULL));

> and test a little bit with emacs -Q and nothing break.  So I think
> you're right: when w->desired_matrix is NULL, both are.

BTW, did you build with checking?