Pressing multiple times ENTER fast throws errors or results in strange behaviour

[ellatrix]

Some things I noticed since #1989:

• After a pressing enter fast for a while, it stops creating new blocks.
• Sometimes it adds a line break in front of the block's content (also fast).
• Sometimes it throws this error:

Warning: validateDOMNesting(...): <p> cannot appear as a descendant of <p>.

Related: #2112

[hedgefield]

I don't seem to be able to reproduce the first point (how long would you say is "a while"?), but I do see the line breaks appearing sometimes - basically as if you pressed shift+enter in between enters.

Also, when backspacing all those new blocks, it seems the linebreaks 'travel up' too, combining into one block with multiple linebreaks along the way (or appending it to an existing block with text in it). It's like the way drops of water form a bigger puddle when they come in contact with each other, is the only way I can describe it.

[moorscode]

Holding the enter key will reproduce this for me as well.

[ellatrix]

Should be fixed by ab44b9b and 9784041.