bug#36030: Changing the region or the point changes the way characters are displayed

[Eli Zaretskii]

> Cc: 36030@debbugs.gnu.org
> From: Clément Pit-Claudel <cpitclaudel@gmail.com>
> Date: Fri, 31 May 2019 16:51:10 -0400
> 
> > The font doesn't change, just the glyph number reported by Emacs
> > changes (that's what that hex code in parentheses means).
> 
> But it also changes from FreeSans to FreeMono; isn't that a font change?

Right, missed that among all the noise, and similar font names.

> > I see none of that in "emacs -Q".  I also don't understand how
> > resizing the frame could cause these effects.  If the recipe is more
> > complicated than just copy/paste the strings you show into *scratch*,
> > please be sure to show the whole recipe.  E.g., where did the face
> > properties come from?
> 
> This is python-mode's syntax highlighting.  Unfortunately, I don't have a 
> reproducible recipe for these issues yet; they happen on my machine, but I 
> have many custom fonts and Emacs customization here.  I will try to find a 
> recipe.

A recipe is very important to solve this issue, because something very
strange happens here.  Are your Python faces specify fonts or font
families, per chance?