surface errors when connection reset through pipeline

[weissi]

Motivation:

Previously, NIO wouldn't send errors that we pulled out of the socket on
connection reset through the pipeline. That meant that you wouldn't for
example see connect errors.

Modification:

Send errors through the pipeline if the channel is still alive after
trying to read all bytes.

Result:

• More erorrs surfaced to the user.
• fixes NIO doesn't necessarily send ECONNRESET and other errors on reset() through pipeline #1756

[weissi]

@Lukasa this isn't actually too bad at all. The real changes required are pretty minor. The cool thing is that my change only does much if the channel is still open after readEOF0. But if we do see an error there, then it'll be closed there and things should be fine because we never get to the new logic. If we do survive readEOF0 without an error, then we should actually surface the error.

This needs much more testing and analysis, therefore still WIP. But I'll do that when I'm actually back at work :)

[weissi]

this is obviously ugly, we have a similar issue elsewhere that we have "errors" that aren't errors.

[weissi]

Aged out, closing.