bug#20628: 25.0.50; Incorrect line height for some fonts

[Clément Pit--Claudel]

On 05/22/2015 02:43 PM, Eli Zaretskii wrote:
>> From: Oleh Krehel <ohwoeowho@gmail.com>
>> Cc: clement.pitclaudel@live.com,  20628@debbugs.gnu.org
>> Date: Fri, 22 May 2015 20:18:17 +0200
>>
>> Eli Zaretskii <eliz@gnu.org> writes:
>>
>>>> From: Oleh Krehel <ohwoeowho@gmail.com>
>>>> Cc: clement.pitclaudel@live.com,  20628@debbugs.gnu.org
>>>> Date: Fri, 22 May 2015 18:54:17 +0200
>>>>
>>>> I attach a patch that sets ascent/descent to 0 specifically for the
>>>> problematic font family "Latin Modern Math".
>>>
>>> That's hardly TRT.
>>
>> Why not?
> 
> Because you assume no one will want to see that font in its original
> metrics, and don't provide any way for users that might want that to
> get that back.  There's no "fire escape".

If we don't find what causes this strange ascent computation, and as a slightly 
more general approach that the patch above, what about including an 
ascent-override-alist at the Lisp level, which could by default contain ("Latin 
Modern Math" . 0) and maybe other entries for a number of other Latin Modern 
variants?