Re: Height of Unicode chars is not right

[Eli Zaretskii <eliz@gnu.org>]

> Date: Tue, 22 Sep 2015 09:08:38 -0700 (PDT)
> From: Rusi <rustompmody@gmail.com>
> 
> On Tuesday, September 22, 2015 at 9:21:25 PM UTC+5:30, Óscar Fuentes wrote:
> > Grant Rettke  writes:
> > 
> > > On Tue, Sep 22, 2015 at 10:13 AM, Rusi  wrote:
> > >> Some unicode chars display with excessive height
> > >> eg if the file (buffer) has these 3 lines
> > >
> > >> emacs shows the ∀ as having 3 lines and the cursor triples its height on that
> > >> The fraktur L 𝔏 looks like 5 (2 above 2 below)
> > >>
> > >> What should I do?
> > >
> > > What version of Emacs are you using? 
> 
> 24.4.1

The development sources fix this problem.

> > And check that the font used for those Unicode chars is the same as for
> > the ASCII chars. Sometimes Emacs will swith to another font for
> > displaying certain chars despite the default font having support for
> > those chars.
> > 
> > M-x describe-char with the cursor on the interesting char will tell you
> > the font used.
> 
> C-u C-x = for these three give
> 
> ∀: xft:-unknown-TeX Gyre Termes Math-normal-normal-normal-*-17-*-*-*-*-0-iso10646-1 (#xEFE)
> 
> a: xft:-unknown-Ubuntu Mono-normal-normal-normal-*-17-*-*-*-m-0-iso10646-1 (#x44)
> 
> 𝔏: xft:-unknown-Latin Modern Math-normal-normal-normal-*-17-*-*-*-*-0-iso10646-1 (#xD99)

The Latin Modern Math font (and many other "math" fonts) specify a
preposterously large global height value.  Previously, Emacs always
obeyed that global value, with the effect that you see.  In the
development sources, we ignore such large values, and instead compute
our own value using the actual characters from the font.

If you want to work around that in Emacs before 25.1, find a font that
supports those symbols, but does not specify such large height values.