bug#34035: 26.1; Arabic shadda-kasrah renders incorrectly

[Peter]

> Thanks.  On my system, this is displayed correctly, with kasrah above
> the letter.  So I don't think it's Emacs, I think it's the shaping
> engine you are using.  As you didn't provide the information collected
> by "M-x report-emacs-bug", I can only guess what is that shaping
> engine: XFT and libflt, right?  Maybe you could try building the
> harfbazz branch, which uses HarfBazz for shaping, I'd expect this
> problem not to exist there.

Thanks, I'll try this. The reason I didn't include that information is
that I sent the email from my "outer" emacs running exwm, but tried with
an "inner" emacs with emacs -Q (which is a rather inconvenient way of
running emacs ;).

Seems to be XFT and libflt:

  Configured using:
   'configure --prefix=/usr --sysconfdir=/etc --libexecdir=/usr/lib
   --localstatedir=/var --with-x-toolkit=gtk3 --with-xft --with-modules
   'CFLAGS=-march=x86-64 -mtune=generic -O2 -pipe -fstack-protector-strong
   -fno-plt' CPPFLAGS=-D_FORTIFY_SOURCE=2
   LDFLAGS=-Wl,-O1,--sort-common,--as-needed,-z,relro,-z,now'
  
  Configured features:
  XPM JPEG TIFF GIF PNG RSVG IMAGEMAGICK SOUND GPM DBUS GSETTINGS NOTIFY
  ACL GNUTLS LIBXML2 FREETYPE M17N_FLT LIBOTF XFT ZLIB TOOLKIT_SCROLL_BARS
  GTK3 X11 MODULES THREADS LIBSYSTEMD LCMS2

I'll try that branch. Are there plans to move emacs head over to
harfbuzz at any point in the future?

Greetings and thanks for your help!

Peter