bug#81570: 31.0.90; window-text-pixel-size sometimes does not correctly determine the width of characters with face attribute :box
Eli Zaretskii <[email protected]>
| Newsgroups | gmane.emacs.bugs |
|---|---|
| Message-ID | <[email protected]> |
> Cc: [email protected], [email protected] > Date: Fri, 07 Aug 2026 14:30:48 +0300 > From: Eli Zaretskii <[email protected]> > > > Cc: [email protected] > > From: Sean Whitton <[email protected]> > > Date: Fri, 07 Aug 2026 11:56:05 +0100 > > > > retitle 81570 30.1; window-text-pixel-size sometimes does not correctly determine the width of characters with face attribute :box > > thanks > > > > Markus Triska [06/Aug 11:24pm +02] wrote: > > > In Emacs versions before d98afc1019d9f177dd05042371dd8239b7901d47, both > > > tests I posted work as expected, yielding 2 and (2 . 2), respectively. > > > > So this problem was not introduced by Emacs 31. > > This regression (if it is a regression: I'm not yet sure) was > introduced in Emacs 28.1. Upon further investigation, I concluded that this is indeed a regression, which I hope I fixed now on the master branch. FTR, a similar problem happened with the return value of posn-at-point after inserting the text having a :box face: the X coordinate was off by one before the fix, for the same reason. The reason was that the code which simulates display layout was losing the information about the start-of-box at the beginning of the line.