Unexpected behavior when using backspace/replacing content in the text editor

[DrewAPicture]

I'm seeing some strange behavior when using backspace or replacing content in the text editor.

It's kind of hard to explain. The gist is that I'd expect to be able to just edit text without the scroll position jumping around in the textarea.

Right now, if I'm editing a line midway down the page, when I hit backspace, the line force jumps up to where the current line I’m editing is at the bottom of the textarea. This happens every time I hit backspace - edit a line halfway down, hit backspace or replace some content and it jumps to the bottom, I scroll back up, lather, rinse, repeat.

As you can imagine, the constant jumping around can be pretty annoying if you're editing a lot of content!

Here's a screencast demonstrating the problem: ​https://cloudup.com/cfgNJUSTp40

Reproduced in Chrome and Firefox in current trunk.

[DrewAPicture]

Hmm. After further testing, I think this might be localized to DevHub. Will reopen if I can reproduce elsewhere.

[DrewAPicture]

Nope, nevermind, reproduced on local trunk in Firefox.

[azaozz]

In 37684:

Editor: prevent jumping when using the backspace button in the Text editor in Firefox and IE.

Fixes #37072.