notofonts/noto-fonts

Two Tibetan banned chars are garbled

Mercury13 opened this issue · 1 comments

Defect Report

Title

Tibetan 0F77 and 0F79 are garbled

(they are banned and should not exist in actual text, but is it possible to showcase them somehow?)

Font

NotoSerifTibetan-Regular.ttf

Where the font came from, and when

Site: this repo
Date: 2022-04-07

Font Version

2.101

OS name and version

Win10 21H1

Application name and version

Qt 6.1.2, probably all OS

Issue

  1. Draw 25CC+0F77, 25CC+0F79
  2. Look badly
  3. Should look good

Character data

25CC Dotted circle
0F77 Tibetan vowel sign Vocalic Rr

25CC Dotted circle
0F79 Tibetan vowel sign Vocalic Ll

Screenshot

image
image

The problem is due to the ordering of features. blwm contains the mark-to-mark positioning rules but this is being run before mark which contains the mark-to-base positioning rules. So the two below marks are first being correctly positioned relative to each other, and then erroneously attached to the same base glyph. Giving these features an explicit ordering seems to fix it.

shape