In vertical type every character now sits in its own cell down the column:
"10" and "22" in 「10月22日」 stand side by side in one em, centred on the
column, and 月/日 start right after them. Justified (Justify All) columns
no longer split a tate-chu-yoko block, and tracked or justified upright
characters stay on the column's centre line instead of drifting across it.
Root cause: in 0.3.1 (the reporter's build) upright glyphs were placed by
the font's ascent rather than the ideographic em box, so a font with a tall
ascent (Noto Sans CJK JP, 1.16 em) drew each upright character ~0.28 em
down into the next cell, onto the sideways digits; #208 (after 0.3.1)
replaced that with em-box placement and tate-chu-yoko, which this commit
locks in with regression tests. Two defects of the same kind remained:
Justify All added its inter-character gap inside a tate-chu-yoko block
(the block's second digit slid down the column, away from the first), and
upright glyphs turned about the middle of their advance, which tracking and
justification lengthen, instead of the middle of their own cell.
Tests: the issue's layout with bundled glyphs (cells one after the other,
every ink inside its cell and no overlaps, 2-3 digit blocks one em and
centred, single digits and 2026 on their side advancing by their length,
spaces), the issue's string with craft-fonts' Japanese face (skips without
craft-fonts), Justify All with a block, tracking.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>