## Summary
* **What is the goal of this PR?** Fixing two independent CSS rendering
bugs combined to make hanging-indent list styles
(e.g. margin-left:3em; text-indent:-1em) render incorrectly:
* **What changes are included?**
1. Negative text-indent was silently ignored
Three guards in ParsedText.cpp (computeLineBreaks,
computeHyphenatedLineBreaks,
extractLine) conditioned firstLineIndent on blockStyle.textIndent > 0,
so any
negative value collapsed to zero. Additionally, wordXpos was uint16_t,
which
cannot represent negative offsets — a cast of e.g. −18 would wrap to
65518 and
render the word far off-screen.
2. extraParagraphSpacing suppressed hanging indents
Even after removing the > 0 guard, the existing !extraParagraphSpacing
condition
would still suppress all text-indent when that setting is on (its
default). Positive
text-indent is a decorative paragraph indent that the user can
reasonably replace with
vertical spacing — negative text-indent is structural (it positions the
list marker)
and must always apply.
3. em unit was calibrated against line height, not font size
emSize was computed as getLineHeight() * lineCompression (the full line
advance).
CSS em units are defined relative to the font-size, which corresponds to
the
ascender height — not the line height. Using line height makes every
em-based
margin/indent ~20–30% wider than a browser would render it, and is
especially
noticeable for CSS that uses font-size: small (which we do not
implement).
## Additional Context
Test case
```
.lsl1 { margin-left: 3em; text-indent: -1em; }
<div class="lsl1">• First list item that wraps across lines</div>
<div class="lsl1">• Short item</div>
```
Before: all lines of all items started at 3 em from the left edge
(indent ignored).
After: the bullet marker hangs at 2 em; continuation lines align at 3
em.
<img width="240" alt="before"
src="https://github.com/user-attachments/assets/9dcbf3e0-fcd9-4af8-b451-a90ba4d2fb75"
/>
<img width="240" alt="after"
src="https://github.com/user-attachments/assets/1ffdcf56-a180-4267-9590-c60d7ac44707"
/>
---
### AI Usage
While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.
Did you use AI tools to help write this code? _**YES**_
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