bug#64547: closed (`show-paren-mode` thinks that a paren is offscreen in `M-:` when it isn't)

[GNU bug Tracking System]

Your message dated Sat, 15 Jul 2023 10:22:10 +0300
with message-id <838rbhej19.fsf@gnu.org>
and subject line Re: bug#64547: `show-paren-mode` thinks that a paren is 
offscreen in `M-:` when it isn't
has caused the debbugs.gnu.org bug report #64547,
regarding `show-paren-mode` thinks that a paren is offscreen in `M-:` when it 
isn't
to be marked as done.

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64547: https://debbugs.gnu.org/cgi/bugreport.cgi?bug=64547
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--- Begin Message --- Subject: `show-paren-mode` thinks that a paren is offscreen in `M-:` when it isn't Date: Sun, 09 Jul 2023 19:49:06 +0000

Hello,

I have `show-paren-style` set to `mixed` and 
`show-paren-context-when-offscreen` set to `overlay`.

When using `eval-expression`, `show-paren` thinks that the starting 
parenthesis is offscreen.

I have attached images showing how, although I am typing on the same 
line as the parenthesis, the context overlay is still shown.

With `show-paren-when-point-inside-paren` enabled, typing before the 
closing parenthesis causes the prompt of `M-:` to be shown before 
quickly being hidden by the context overlay again. This causes text to 
quickly move side to side as I type. I have attached a screen recording 
of this movement.

This is in Emacs 29.0.92. If it is relevant, I have `line-spacing` set 
to 0.15.

Thank you.

without-context.png
Description: PNG image

with-context.png
Description: PNG image

show-paren-movement.mp4
Description: video/mp4

--- End Message ---

> --- Begin Message ---
>
>
>
> Subject: 
>
> Re: bug#64547: `show-paren-mode` thinks that a paren is offscreen in `M-:` when it isn't
>
>
>
>
> Date: 
>
> Sat, 15 Jul 2023 10:22:10 +0300
>
>
>
>
> > Date: Sat, 15 Jul 2023 01:06:54 +0000
> > From: okamsn@protonmail.com
> > Cc: 64547@debbugs.gnu.org, stephen.berman@gmx.net
> > 
> > 1) Start `emacs -q` without the new change to paren.el.
> > 
> > 2) Set `show-paren-context-when-offscreen` to `overlay`.
> > 
> > 3) In a normal buffer (not the minibuffer), move to the end of a long 
> > expression so that the starting parenthesis is no longer on the screen 
> > and is not visible.
> > 
> > 4) See the overlay, as expected.
> > 
> > 5) Move inside the expression so that the overlay is no longer shown.
> > 
> > 6) Evaluate the new definition of `show-paren-function`.
> > 
> > 7) Move back to the end of the long expression.
> > 
> > 8) See that the overlay is no longer shown.
> > 
> > 
> > I expected to see that the overlay would still be shown for the opening 
> > parenthesis that is completely unseen.
> > 
> > I think that this happens because there is an expression `(not ... (or 
> > (< (length part) 4) ...))` which resolves to `nil` when the parenthesis 
> > is not visible and not partially visible, from what I can tell.
> > 
> > Does this make sense?
>
> Thanks, now fixed as you suggested, and closing the bug.
>
>
> --- End Message ---