Bug 36205 – Changing text of a DOM element causes a FLEX element to jump

• Component: Layout and Rendering
• Status: RESOLVED WONTFIX

[Matt]

Created attachment 50860 [details]
Test case

The attached HTML reproduces this in Safari 4.0.4 and Chrome Beta.  

1) Load the HTML into the browser
2) Shorten the browser window height so that the bottom section (the region with 'REST' printing in it) has a scroll bar
3) Scroll to the end of this section
4) click on 'try'
5) Note that the first line of the HTML now changes (via a JavaScript call)
6) ...and the 'REST' scrollable region jumps.

This jump sure seems like a bug.  It's undesirable, and does not occur in Firefox.

Workarounds are welcome!  The technique used is the only way I've found to achieve this effect (scrollable bottom that takes what's left from an upper region), but this behavior makes this undeployable.

[Ahmad Saleem]

If I am following the steps correctly then I am not able to reproduce this in Safari 16.2, where if I open testcase, make window smaller, go to last "REST try" and when click, it does not change the scroll region (REST....) to jump and it just update first line with "I JUST CHANGED 49" but it does not show any jump etc.
It matches with Firefox Nightly 110 and Chrome Canary 111 with same steps etc., I am marking this as "RESOLVED WONTFIX" because it was never confirmed but tagging others to confirm that my interpretation of steps to reproduce is correct and this is not an issue anymore. Thanks!