add a line to a codeblock is inconsistent

[rupert thurner]

pressing return in a code block is not doing the same in all code blocks.

normal

pressing return adds a line in the code block. if the code block is at the end of a page would be nice that pressing return twice would end the code block and switch to text mode.

in a list

in a list like mentioned in #2118, pressing return makes another list entry. it would be nice if pressing return in the middle of a code block would just add a new line.