Premature submitting of post on paste after newline

primarily Chrome, i’ve also gotten IE and Firefox to do it.

It’s much easier to reproduce when the site is having one of its slow moments, which is much more common on my home forum that it is here on meta.d. i have been able to reproduce it at steady state as well.

Tested configurations that exhibit the issue:

Membrane and mechanical keyboards (i have machines with both types and both types exhibit the bug.)

Logitech G710+ (mechanical)
Surface Pro 2 Type cover (membrane)
Logitech G510s (membrane)
Logitech K800 (membrane)
laptop keyboards (membrane, no known manufacturer other than “Google” and “HP”)

Hardware (CPU, Ram size and hard drive type) reproducable on:

i7 32GB ram SSD (Windows 8.1)
i3 8GB ram SSD (Windows 8)
Celeron 4GB RAM HDD (Windows 7)
i5 Surface (Windows 8.1)
Chromebook Pixel 2015 (Chrome OS)
Phenom x6 6GB ram HDD/SSD (Windows 7)

also this. unless the site/editor is responding sluggishly you have to be really really fast to trigger it.