mintty overstrokes some fonts unexpectedly

[Lemures Lemniscati]

On Sun, 25 Apr 2021 22:33:57 +0200, Thomas Wolff
> 
> Am 25.04.2021 um 15:41 schrieb Lemures Lemniscati via Cygwin:
> > Hi!
> >
> > mintty overstrokes some fonts unexpectedly.
> > https://gitlab.com/test.cases/mintty-test/-/tree/54ae800e695ecd1741851cab57320a9d0e95a6fd
> >
> > I got a result mintty-sample-msgothic.png.
> > https://gitlab.com/test.cases/mintty-test/-/blob/54ae800e695ecd1741851cab57320a9d0e95a6fd/mintty-sample-msgothic.png
> >
> > In the 4th line of the output, fonts (of u+25cb) were overstruck
> > unexpectedly.
> > And there are other characters also, which are similarly overstruck.
> This is a Windows bug. Mintty clearly instruct Windows to apply equidistant spacing to achieve fixed-width character cell behaviour. But for certain character ranges, Windows ignores that. Another example for such misbehaviour is the Tibetan block (U+0F00-U+0FFF). Mintty could work around that by rendering characters separately, at a significant penalty for output speed however. Or it could do that only for affected ranges, but criteria to identify them are obscure.

Thank you, Thomas.

I tried some earlier versions of mintty:

* mintty-3.1.0-1 has the same issue
* mintty-2.9.6-0 works expectedly in this case.

Regards,

Lem