Does this mean the problem is solved, and we can close this bug?

I am not sure. It depends on what is the intended behavior. I would say it is desirable
if inserting text after an image, of height equal to the text height, would not increase
the `line-pixel-height`. The elisp manual mentions that the default value for :ascent is
50, in which case the `line-pixel-height` is larger than the both the 'image height' and
the 'text height'. So maybe the default value of :ascent should be 80, in which case
the 'line-pixel-height' 'remains' equal to the image height and text height.

However, there might be various arguments for the current default value of 50 (and its
behavior of increasing the 'line-pixel'height' when combining images with text on a
single line).

> I would think that this :ascent of 80, behaves how :ascent 50 (the default)
> is supposed to behave?

I don't think I understand the question.

I mean that I would expect the default behavior to be that, when combining images and
text of equal height on a single line, the 'line-pixel-height' would also be/stay of equal
height.
But as mentioned before, there might be various arguments for the current behavior,
however (as a layman) I am not aware of any.

If the current behavior is the desired behavior, then indeed this issue can be closed.

On Sun, 3 Apr 2022 at 14:03, Eli Zaretskii <eliz@gnu.org> wrote:
> From: dalanicolai <dalanicolai@gmail.com>
> Date: Sun, 3 Apr 2022 13:03:27 +0200
> Cc: 54688@debbugs.gnu.org
>
> Playing around with :ascent, makes possible to keep the line-pixel-height fixed.
>
> So in the following I simply use `insert-image`. Without the :ascent, the
> 'line-pixel-height' increases when inserting another character. With the
> :ascent it is possible to reduce this 'increase'. For me the increase is 0
> when I use an ascent value of 80.
> (below the used code)
>
> (with-current-buffer (get-buffer-create "test")
>   (setq left-margin-width 5)
>   (insert-image (svg-image (let* ((ph (line-pixel-height))
>                                   (size ph)
>                                   (svg (svg-create size size)))
>                              (svg-circle svg ph ph ph :fill "red")
>                              svg)
>                            :ascent 80))
>   (switch-to-buffer (current-buffer)))

Does this mean the problem is solved, and we can close this bug?