If multiple requests are received in one batched, the LWT backend blocks after the first. about httpaf

[mefyl]

I'm toying around with a solution that "works", but the interaction between the common code and the asynchronous is a bit convoluted and I end up causing active waits. I should be able to come up with something, but if someone with more experience on the code has a simple fix, happy to get help.

[mefyl]

My solution here is to simply call the request parser until either no progress is made or no more data is available. This looks correct to me, but maybe slightly sub-optimal as it may be possible to better determine whether we can make more progress without systematically calling the parser once more if there is any data left available. In any case it does seem to fix our current issue, while not causing any busy loops.