Scroll bar on MR changes view doesn't correspond with actual content being scrolled

Summary

The scroll bar on the merge request changes (diffs) view does not correspond with the actual content being scrolled. The scroll bar position/size does not accurately reflect the user's position within the diff content.

Steps to reproduce

  1. Open a merge request with a large diff
  2. Navigate to the Changes tab
  3. Scroll through the diff content
  4. Observe that the scroll bar position/size does not match the actual content being scrolled

What is the current bug behavior?

The scroll bar on the MR changes view does not correspond with the actual content that's being scrolled — the scroll indicator is misaligned or incorrectly sized relative to the real content length/position.

What is the expected correct behavior?

The scroll bar should accurately reflect the user's current position within the diff content and correctly represent the proportion of content visible vs. total content.

Relevant logs or screenshots

A screen recording would help reproduce this — to be added if available.

Environment

  • Browser: Chrome (scroll bugs in Chrome have been noted as a known area)
  • Feature area: Merge request diffs / Changes tab (rapid diffs viewer)

Additional context

Reported in an internal Slack thread. A team member noted there are known scroll bugs in Chrome that may be related. No existing open issue was found that specifically matches this symptom.

Edited by Chaoyue Zhao