`Preferences::default()` is Servo's conservative library default and
ships `layout_grid_enabled: false`. `Servo::new` forwards prefs to Stylo
(`prefs::set` -> `stylo_static_prefs::set_pref!("layout.grid.enabled")`),
so with the gate off Stylo blockifies `display: grid`: every grid
container collapses to `display: block` and grid-based page layouts
stack into a single column — the "broken" rendering reported on modern
sites.
`ely_servo_preferences()` only flipped `dom_intersection_observer_enabled`
and inherited the grid default, so ELY rendered grid pages collapsed
while Servo's own servoshell (which enables the pref) renders them
correctly. The layout path is implemented — servo-layout drives
`DisplayInside::Grid` through Taffy — so enabling the pref is the real
fix, not a workaround.
Verified with a deterministic `display: grid; grid-template-columns:
1fr 1fr 1fr` page: 9 stacked full-width bars before, a 3x3 grid after.
Wikipedia/HN/GitHub/google.com re-checked unchanged; full workspace
test suite green.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
ZacharyZhang-NYandClaude Opus 4.8
3d36cb25bf