Assertion on content-length mismatch

[zevv]

Reproduce with

import options, asyncdispatch

import httpbeast

proc onRequest(req: Request): Future[void] =
  if req.httpMethod == some(HttpPost):
    case req.path.get()
    of "/":
      req.send("Hello World")
    else:
      req.send(Http404)

run(onRequest)

Then send a faulty HTTP request with:

curl -v -XPOST http://127.0.0.1:8080/ -d/etc/services -H "Content-Length: 12"

Results in:

httpbeast.nim(421)       run
httpbeast.nim(414)       run
httpbeast.nim(287)       eventLoop
httpbeast.nim(203)       processEvents
httpbeast.nim(140)       bodyInTransit
system.nim(3877)         failedAssertImpl
system.nim(3870)         raiseAssert
system.nim(2916)         sysFatal
Error: unhandled exception: /home/idoornekamp/.nimble/pkgs/httpbeast-0.2.1/httpbeast.nim(140, 9) `not
  trueLen < bodyLen`  [AssertionError]```

IMHO asserting or throwing on faulty remote data is not right here.

[dom96]

Indeed :)

This is why you should put nginx in front of httpbeast, for now at least.

We need to properly fuzz httpbeast and fix these issues, with hopefully as little performance regressions as possible.