Main scrollbar sampler: this page.
Reflection pre-paint sampler: Open reflection sampler
This reproducer uses a scroller with fractional content size
(200.5px) inside a parent at fractional position
(left/top: 0.5px). With the fix, accumulated paint-offset
snapping makes off0 and off.5 diverge by about 1px
in effective clamp on at least one axis.
On unpatched builds, ContentsSize() uses local-only snapping
and ignores accumulated paint offset, so off0 and
off.5 clamp the same.
Waiting...
Waiting...
Compare off0 and off.5. If their deltas differ by
about 1px on at least one axis (pair_diff ~= 1), this is
patched behavior. Which offset has the larger delta may vary by platform.
off0 and off.5 produce the same delta values
(pair_diff ~= 0). Absolute deltas may be 0,
0.5, etc., but they do not separate by offset.
<div style="position: relative; left: 0.5px; top: 0.5px;">
<div style="width: 120px; height: 120px; overflow: scroll;">
<div style="width: 200.5px; height: 200.5px;"></div>
</div>
</div>