bug#15138: Font rendering error on OSX

[Michael Toomim]

A simple way to reproduce this bug is to press option-8 (inserts a bullet on a 
mac) anywhere in a text buffer. You can see the line grow taller.

In default OSX settings, you'll need to (setq ns-alternate-modifier 'none) 
before you can use option-8.

On Aug 19, 2013, at 7:37 PM, Michael Toomim <toomim@gmail.com> wrote:

> Some extended characters are rendered incorrectly in the new Cocoa 24.3 emacs 
> on OSX. They are rendered:
>    - too small
>    - too tall (forcing an increase in line-height of a pixel or two)
> 
> The result is that some lines are too tall, and monospace layouts (like ASCII 
> art) lose alignment.
> 
> Here is an example in three screenshots, where the "•" bullet character is 
> rendered incorrectly. The first screenshot shows the bug on the current 
> release. You can see that the center line takes up too much vertical space, 
> and not enough horizontal space. This is a monospace font (apple monaco).
> 
> The second and third show the correct rendering. The second is an older emacs 
> build I have that rendered text with Carbon. The third is Apple's native 
> TextEdit.app, for reference.
> 
> 
> <PastedGraphic-21.png>
> <PastedGraphic-19.png>
> <PastedGraphic-20.png>