IDML names some languages by locale code
(AppliedLanguage="$ID/de_DE_2006", "$ID/nl_NL_2005") beside names such
as "English: USA" and "Spanish: Castilian". language_tag maps any locale
code (ll, ll_CC, ll-CC, with a reform year after them) to its BCP 47 tag
(de-DE, nl-NL; kept once per process, at most 512 distinct tags), ignores
IDML's $ID/ prefix, and knows Spanish: Castilian (es-ES) and Swiss French
and Italian. The stored name stays as written, so IDML round trips are
unchanged.
What depends on the language now goes by the tag: typographer's quotes
(by language subtag; Swiss regions take guillemets), English
hyphenation and spelling (is_english), Korean word breaking and the CJK
fallback chains (ja-JP, ko-KR are Japanese and Korean whatever the
region).
A character the applied font lacks is drawn as that font's missing-glyph
box (its .notdef, gid 0), on screen and in PDF, and Preflight lists the
characters by font ("Missing glyphs in <family> <style>: …", an error,
at most 20 named). A .notdef without an outline is drawn as a hollow box
across its advance, so a missing character never disappears. PDF draws
.notdef glyphs as paths, which PDF/A and PDF/UA accept. Kenten marks are
set in their text's font the same way.
The document setting Draw Missing Glyphs from Fallback Fonts
(DocSettings::glyph_fallback; Preferences > Composition,
document.preferences {glyphFallback}, undoable) draws them from fallback
fonts instead (the language-aware chains, then any font; kenten marks
from a fallback font, else a bullet). It is off in new documents and
IDML imports and on in files saved before it existed, which keep
drawing as they did. A missing font's substitute always uses fallback
fonts. The composition cache's signature includes the setting. Tests
whose Arabic comes from a fallback font turn the setting on.
language_tag ignores case and punctuation and recognises Chinese in its
common spellings and locale codes (Simplified Chinese, Chinese
(Simplified), zh_CN, zh-Hans; Traditional Chinese, zh_TW, zh_HK,
zh-Hant), and Japanese and Korean locale codes (ja_JP, ko_KR).
Typographer's quotes for Chinese and Japanese follow the tag, so every
spelling takes the same quotes. IDML import keeps the name as written.
The fonts in a document's Document Fonts folder are registered under a
font scope that the document holds while it is open (Document::font_scope,
runtime only; DocState keeps the scope alive and closes it when the last
copy of the state goes: file.close, closing a tab, revert, a book
chapter's export, the session ending). Composition, preflight, font.list,
Package and the font menus, Glyphs panel and previews look fonts up
through FontDb::scoped(scope): the document's own faces first, then the
shared ones. Other open documents don't see them, and two documents with
fonts of the same name each set text in their own. Composite fonts'
member fonts and the fallback for kenten marks are looked up the same
way.
Font files stay in memory for the session (FaceRef keeps faces for the
process); a document opened again reuses the faces of its unchanged files
(same path, length and modification time) instead of reading them again.
The composition cache's signature includes the scope; the word cache and
the outline and PDF font caches are keyed by face. Variable font
instances are kept per base face.
A family's installed faces join the shared fonts all at once, and a
face two lookups load at the same time is kept once, so a parallel
fallback lookup never takes a family's bold before its regular has
loaded.
Vertical is a story property: every frame of a thread is vertical or
horizontal together, a frame threaded onto a story takes its direction,
and frames split off by threading or breaking a thread keep theirs.
Type > Story Direction is type.storyDirection {vertical} (checked in the
menu) for the stories of the text selection or selected frames;
object.textFrameOptions {vertical} and frame.create {vertical} set the
frames' stories. Documents that stored Vertical on the frame open with
each story taking its first frame's direction. IDML StoryOrientation is
read into and written from the story, beside its column direction
(StoryDirection), which stays a separate setting.
Korean is set word by word (KLREQ): Hangul, in any language, and Han
ideographs in Korean-language text take no line breaks between
characters, so lines break at spaces. Glyphs carry their language tag
for this. A paragraph attribute, koreanCharBreaks (type.para, paragraph
styles, Paragraph Style Options > Justification), breaks between
syllables instead. It is DesignCraft-only; IDML doesn't carry it.
A paragraph's kinsoku set decides which breaks it forbids, and Korean
still breaks at spaces under one.
Kinsoku still holds, also when the single-line composer has to split a
word wider than the measure: the split moves back so no line starts
with closing punctuation.
The character's language (as IDML names it) maps to a BCP 47 tag
(designcraft_doc::language_tag) and is the shaping context's language
on the harfrust buffer, so OpenType locl applies for every language in
the list (Japanese, Chinese, Korean, Turkish, ...), not only Arabic,
Persian, Urdu, Hebrew and English: other names used to reach the
shaper as they were written, which it doesn't know, so their locl never
applied. designcraft_fonts no longer maps names itself. The word-shaping
cache is keyed by the tag. Chinese: Simplified and Chinese: Traditional
join the language list (plain Chinese stays, tagged zh); Simplified
Chinese takes curly quotes, Traditional Chinese corner brackets.
Port the CJK1 and AR1 changes from 3ecdb78 and de83cdc onto current main. Resolve translation and font-stack conflicts by retaining main localization and craft-fonts integration while preserving all typesetting code, tests, and documentation.
Validation: all six CI gates passed, including 616 tests and WASM checks.
expect() calls become let-else / fallbacks. A parent spread without pages
(possible in a .designcraft file) no longer underflows in parent_page_for,
and check() rejects a next_id so large that allocating ids would overflow.
Both crates deny the panicking lints.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
