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 2020-10-31 09:38:37 +0200, Eli Zaretskii wrote:
> I think the issue might be elsewhere: in the code that decides to
> scroll such that this particular screen line ends up being the last
> one, and/or that point should be on this last line.  If this happens,
> we will always recenter or move point off that screen line.  So the
> right place to look could be in the scrolling code, probably in
> window_scroll_pixel_based.

window_scroll_pixel_based is not called at all, neither window_scroll
is.

What is wrong seems to be the initial position of the text in the
window. Indeed, with xmag (magnifier), I can see that the glyphs
are shifted one line downward. Now, I don't know where to look at.

-- 
Vincent Lefèvre <vincent@vinc17.net> - Web: <https://www.vinc17.net/>
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Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)