bug#48610: texinfo heading levels not highlighted by outline-minor-mode

[Juri Linkov]

> This is what I am using
>
> (defvar hdlevels
>    '( ("@chapter" . 1)
>       ("@section" . 1)
>       ("@subsection" . 2)
>       ("@subsubsection" . 3)
>       ;; ---------------------------------------------------------
>       ("@unnumbered" . 1)
>       ("@unnumberedsec" . 1)
>       ("@unnumberedsubsec" . 2)
>       ("@unnumberedsubsubsec" . 3)
>       ;; ---------------------------------------------------------
>       ("@appendix" . 1)
>       ("@appendixsec" . 1)
>       ("@appendixsubsec" . 2)
>       ("@appendixsubsubsec" . 3)
>       ;; ---------------------------------------------------------
>       ("@majorheading" . 1)
>       ("@chapheading" . 1)
>       ("@heading" . 1)
>       ("@subheading" . 2)
>       ("@subsubheading" . 3) )
>    "Sets heading names and levels for texinfo files." )

I tried your definitions, and then outlines are highlighted.

I wonder why outline-regexp defined in texinfo-mode is broken?
What would be a correct regexp for texinfo-mode?