Page MenuHomePhabricator

Page should not automatically scroll up while selecting near the top
Open, LowPublicBUG REPORT

Description

Steps to replicate the issue:

  • Visit any page with Vector-2022 skin on a desktop computer
  • Scroll down.
  • Click (keep mouse down) on the 10th text line from the visible top. Even worth: on the 2nd text line from the visible top.
  • Move your cursor slowly toward the top: you’re highlighting the text.

What happens?:
When your cursor arrives at about 60px from the visible top (viewport eventually shifted by sticky header), the page starts to automatically scroll up.
Even worth case: you’re already in the “60px zone”, so the page very quickly scrolls up.

What should have happened instead?:
The scroll should only happen when the cursor leaves the visible part (viewport, or sticky header when there is one).

Other information:
Tested with both Firefox and Chromium on Debian.

Event Timeline

I can’t reproduce anymore while being logged out, but it is still reproducible being logged-in.

LGoto triaged this task as Low priority.May 4 2023, 5:14 PM
LGoto moved this task from Incoming to Groomed on the Web-Team-Backlog board.

It seems this behavior was a side effect of the fix for T290518, which modifies the scroll-padding-top property of the root <html> element in the CSS so section links don't get obscured by the sticky header in Vector 2022. When I temporarily disable this rule in Inspect Element, the scrolling behavior during selection is much better behaved, though the threshold doesn't reach the header still.