Created attachment 416285 [details]
Safari rendering of various slanted vertical text

Safari's rendering (Version 14.0 (15610.1.28.1.9, 15610)) of "font-style: oblique -15deg" for vertical text is not entirely correct. This can be seen on this page: https://output.jsbin.com/juyawoh 
The rendering of basic Japanese characters is correct but there are 3 problems by order of priority (highest first):
- the rendering of upwards latin character is not correct (should be slanted in the reverse direction, i.e. upwards instead of downwards), 
- text-combined characters should be slanted vertically, towards the top (not horizontally towards the right), 
- and the same applies to sideways text to avoid the collision.

Chrome Canary has fixed the first and third problem.
Firefox has the same third problem, a slightly less visible problem for the first one.

Chrome, Safari and Firefox have the same problem for text-combined characters.

Related tickets:
- Firefox: https://bugzilla.mozilla.org/show_bug.cgi?id=1616995
- Chrome: https://bugs.chromium.org/p/chromium/issues/detail?id=1112923