Please credit `svenryen, nattie, joseph.olstad, mforbes, bwaindwain` from #2908543: Tabledrag is broken when you've scrolled down on the page in chrome 61
Problem/Motivation
After two recent commits, the drag and drop behavior is bugged in IE11: when dragging the bottom item, the page is scrolled to the top of the page.
Behavior before (7.50):
Current behavior (7.53):
The related commits are:
- #1261002: Draggable tables do not work on touch screen devices
- #2821441: Newer Chrome versions and IE11/Edge cannot drag and drop anymore on desktop after 7.51 update when jQuery is updated to 1.7-1.11.0
Proposed resolution
Return the drag and drop behavior in IE11 to the state of Drupal <7.51
Remaining tasks
- Write a patch
- Review
- Commit
User interface changes
The drag and drop behavior in IE11 is unchanged compared to Drupal <7.51
API changes
None
Data model changes
Note to maintainers
We have two solutions in #81 and in #87, which both solve the problem, but have slight differences in how they check for NULL or UNDEFINED values. The "rtbc" applies to both of them (I think).
All arguments for either solution have been articulated in the comments.
Recent commenters have tested #87.
A maintainer should make a judgement call, and apply one of them.