It definitely looks like that, because it doesn't happen on my macOS Emacs
(compiled from the same git as for Linux). When I return home, I was
thinking about compiling Emacs on Linuux for GTK3 but disabling CAIRO...
would that make eny sense?

/PA

On Mon, 21 Nov 2022 at 01:35, Po Lu <luangruo@yahoo.com> wrote:

> Dmitry Gutov <dgutov@yandex.ru> writes:
>
> > On 20.11.2022 02:36, Po Lu via Bug reports for GNU Emacs, the Swiss
> > army knife of text editors wrote:
> >> Dmitry Gutov<dgutov@yandex.ru>  writes:
> >>
> >>> No change since the last test I tried: fonts seem fine, but the frame
> >>> size is jumping. I even did 'make bootstrap' to be doubly sure.
> >> Thanks.  Could you place a breakpoint on `apply_xft_settings' before
> >> starting "emacs -Q", step through it, and try to find out what causes
> >> the `changed' variable to be set to true?
> >
> > Apparently it's this part:
> >
> > #ifdef FC_HINT_STYLE
> >   if ((settings->seen & SEEN_HINTSTYLE) != 0
> >       && oldsettings.hintstyle != settings->hintstyle)
> >     {
> >       FcPatternDel (pat, FC_HINT_STYLE);
> >       FcPatternAddInteger (pat, FC_HINT_STYLE, settings->hintstyle);
> >       changed = true;
> >       oldsettings.hintstyle = settings->hintstyle;
> >     }
> > #endif
> >
> > Here's the relevant part of the gdb log, since I don't have much
> > experience with it. The assignment statement itself seems to be
> > missing from the stepping, but 'changed' became true after:
> >
> > (gdb) n
> > 842       FcPatternGetDouble (pat, FC_DPI, 0, &oldsettings.dpi);
> > (gdb) p changed
> > $2 = false
> > (gdb) n
> > 844       if ((settings->seen & SEEN_AA) != 0 && oldsettings.aa !=
> > settings->aa)
> > (gdb) n
> > 852       if ((settings->seen & SEEN_HINTING) != 0
> > (gdb) n
> > 860       if ((settings->seen & SEEN_RGBA) != 0 && oldsettings.rgba !=
> > settings->rgba)
> > (gdb) n
> > 869       if ((settings->seen & SEEN_LCDFILTER) != 0
> > (gdb) n
> > 879       if ((settings->seen & SEEN_HINTSTYLE) != 0
> > (gdb) n
> > 882           FcPatternDel (pat, FC_HINT_STYLE);
> > (gdb) n
> > 883           FcPatternAddInteger (pat, FC_HINT_STYLE,
> settings->hintstyle);
> > (gdb) n
> > 885           oldsettings.hintstyle = settings->hintstyle;
> > (gdb) n
> > 894       oldsettings.dpi = dpyinfo->resx;
> > (gdb) p changed
> > $3 = true
>
> Thanks.  That's quite annoying, I guess Cairo isn't reporting the
> default hint style to us either.
>
> I can't think of a good solution off-hand, please give me some more
> time.
>


-- 
Fragen sind nicht da um beantwortet zu werden,
Fragen sind da um gestellt zu werden
Georg Kreisler

Headaches with a Juju log:
unit-basic-16: 09:17:36 WARNING juju.worker.uniter.operation we should run
a leader-deposed hook here, but we can't yet