_scale_block_fonts rebuilt a block by constructing a plain
Word(word.text, scaled_style) for every word. LinkedWord is a Word
subclass, so the reconstruction downgraded it and dropped the link
target: every hyperlink in the document disappeared the moment the reader
changed font size. Nothing caught it because the function returns the
block unchanged at scale 1.0 with no family override, which is what the
tests exercised.
Add Word.with_style(), overridden by LinkedWord to carry location, link
type, callback, params and title across. Putting the copy behaviour on
the word class means any future Word subclass either inherits a correct
copy or overrides one, rather than being silently flattened by a
constructor call in the layout engine.
Also extend coverage beyond Paragraph and Heading. Quote, HList and Table
were returned unscaled, so a font-size change left quoted text, list
items and table cells at their original size while the surrounding text
reflowed. Table rows are re-added to the section they came from, so a
<thead> row does not become a body row. Image, HorizontalRule, PageBreak
and CodeBlock still pass through: they carry no styled words.
Scaled blocks are now memoised per (block, scale) for the life of the
layouter. Previously a fresh Paragraph and Word were allocated for every
word on every page render at any scale != 1.0, on the hot path, against
the caching work in concrete/text.py.
Tests cover with_style on both word classes, link survival and target
preservation across all four container types, per-container scaling,
table section preservation, memoisation, and that originals are never
mutated. End-to-end: links remain tappable at 0.8x, 1.5x and 2.0x.
Note: query_point's hit region is offset from LinkText.origin by roughly
the ascent, so probing a link's own centre reports "empty". That
reproduces identically at scale 1.0, predates this change, and is tracked
separately as R9 - the end-to-end test scans instead of probing.
891 passed.
Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
