bug#59141: 28.1.90; Face :extend when all the line but trailing \n is invisible

[Al Haji-Ali]

On 11/11/2022, Eli Zaretskii wrote:
> If 'display' and 'invisible' properties start at the same buffer
> position, the 'display' property "wins", because the display engine
> handles it before it handles the invisible property.
I see, thanks for explaining.

What do you think about the suggestion solution of changing the overlay 
rendering to include arbitrary text?

More to the point, what do people think about the making the extent of an 
outline of an entry include a new line? Is that more or less logical than the 
current behaviour?

For example,

,----
| * A
| TextA
| * B
| TextB
`----

Is the content of the "A" entry "\nTextA\n", or is it "\nTextA"?
I would argue it's the former if we consider the whole entry to "A\nTextA\n" 
which is separated into header "A" and content "\nTextA\n".

Best regards,
-- Al