[krisnye]

Hello,

Several of our teams at Adobe are using react-virtualized as part of a native rendering platform. We have an issue where the top rows don't render when you quickly scroll up to the top on a Mac while the scroll bounce animation is causing negative scrollTop values.

This problem likely happens on the web as well IF the rendering of the rows is sufficiently slow. That may make reproducing the original bug difficult.

By removing the early return and simply treating negative values the same as zero we resolve the issue.

• The existing test suites (npm test) all pass
• For any new features or bug fixes, both positive and negative test cases have been added
• For any new features, documentation has been added
• For any documentation changes, the text has been proofread and is clear to both experienced users and beginners.
• Format your code with prettier (npm run prettier).
• Run the Flow typechecks (npm run typecheck).

[bvaughn]

Sorry for the very long delay in getting back to you about this!

I've just finished a large update for version 10 of react-virtualized (#1900): the library has been rewritten in TypeScript, every component is now a function component (React 18+ is required), and the source moved from source/ to lib/. Because of that, this PR can't be merged as-is. Version 10's Grid still ignores scroll events with a negative scrollTop during an overscroll bounce.

If you're still interested in this change, I'd welcome a new PR with it rebased onto the version-10 branch (or onto master once version 10 has been merged).