Improper use of onReadable in HTTPServer within fdbrpc

I see in the documentation for conn->onReadable() that a prior conn->read() which returns 0 is required before calling conn->onReadable(). Does this imply that the HTTP server implementation in fdbrpc is incorrect?

https://github.com/apple/foundationdb/blob/e1300053109c984b27070817792534725daea603/flow/include/flow/IConnection.h#L58-L60

There is no conn->read() call before conn->onReadable in the connectionHandler implementation.

https://github.com/apple/foundationdb/blob/e1300053109c984b27070817792534725daea603/fdbrpc/HTTPServer.actor.cpp#L89-L91

Read the onReadable contract in flow/include/flow/IConnection.h at lines 58-60, then inspect connectionHandler in fdbrpc/HTTPServer.actor.cpp at lines 89-91. Determine whether the HTTP server satisfies the documented precondition; done means resolving the discrepancy by correcting the implementation or clarifying the documentation.

Written by the indexing model from the issue text.