Right-clicking randomly deletes text from the editor

[JordanTheriault]

Right-clicking on elements or properties will delete the text from the editor. After bisection by @humphd it's determined this is a recent regression caused by a recent commit

@humphd: I bisected, and this was caused by a0daa3a upstream.

Here is a screen cap of it happening.

[abose]

Looks like a codemirror upstream issue.
@prafulVaishnav @marcelgerber

[marcelgerber]

Ouch.
codemirror/codemirror5@5d8347d is the upstream culprit.
Let's see if it's our fault or theirs.

[marcelgerber]

Because I might not be able to file these today, I sum up my findings here:
It looks like the content of the hidden textarea changes, which is then picked up by slowPoll.

I verified this is not a Chrome-only bug by successfully reproducing this in Brackets, Bracketron and Bramble with both Chrome and Firefox.

[marcelgerber]

That's what the stack trace looks like, with the downright nonsensical call to applyTextInput in the console below.

[marcelgerber]

Upstream CM bug filed: codemirror/codemirror5#3273

[marcelgerber]

This is now fixed.
Thanks for reporting!