bug#44284: 27.1; with some Unicode font, scrolling upward with the mouse wheel actually scrolls downward when the cursor needs repositioning

[Vincent Lefevre]

On 2020-11-07 10:29:17 +0200, Eli Zaretskii wrote:
> > Date: Sun, 01 Nov 2020 20:47:04 +0200
> > From: Eli Zaretskii <eliz@gnu.org>
> > Cc: 44284@debbugs.gnu.org
> > 
> > > Alternatively, Emacs could use some heuristic: if extents.y_bearing
> > > is very close to an integer, assume that it should be this integer.
> > > This is rather ugly as this might yield unexpected results in some
> > > applications, but would this be OK in Emacs?
> > 
> > It would be okay, I think: we have a few kludgey workarounds for
> > similar issues in other libraries.
> > 
> > I thought about something like using ceil (VALUE - 1/128) or maybe
> > even 1/256, on the assumption that the original integer value cannot
> > be of a greater granularity (the non-Cairo code uses 1/64).
> 
> No further comments, so I pushed such a fix to the master branch, and
> I'm closing this bug report.  Many thanks for your help in debugging
> this problem.

I've just tested, and I confirm that this completely fixes the bug.
Thanks.

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Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
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