bug#63837: 29.0.91; delete-forward-char error with composed text

[Eli Zaretskii]

> From: Thiago Melo <tmdmelo@gmail.com>
> Date: Fri, 2 Jun 2023 10:42:29 +0000
> 
> * How to reproduce:
> 
> 0. Start emacs with `emacs -Q'
> 1. Create some text composition, e.g. eval: `(insert (compose-chars ?+))'
> 2. Move cursor to before composed character
> 3. `M-x delete-forward-char' or press <delete> key
> 
> * Backtrace:
> 
> Debugger entered--Lisp error: (wrong-type-argument sequencep t)
>   lgstring-glyph-boundary(t 1 2)
>   delete-forward-char(1 nil)
>   funcall-interactively(delete-forward-char 1 nil)
>   call-interactively(delete-forward-char nil nil)
>   command-execute(delete-forward-char)

Thanks, should be now fixed on the emacs-29 branch.