HTTP Server crashes with invalid header

httpserver.nim

import parseutils


proc currentNext(header: string): tuple[key, value: string] =
  var i = 0
  var key = ""
  var value = ""

  i = header.parseUntil(key, ':')
  inc(i) # skip :
  i += header.skipWhiteSpace(i)
  i += header.parseUntil(value, {'\c', '\L'}, i)

  return (key, value)


proc newNext(header: string): tuple[key, value: string] =
  var i = 0
  var key = ""
  var value = ""

  i = header.parseUntil(key, ':')
  inc(i) # skip :
  if i < header.len:
    i += header.skipWhiteSpace(i)
    i += header.parseUntil(value, {'\c', '\L'}, i)

  return (key, value)


when defined(usecurrent):
  assert currentNext("something: else") == ("something", "else")
  assert currentNext("something: ") == ("something", "")
  assert currentNext("something") == ("something", "")

else:
  assert newNext("something: else") == ("something", "else")
  assert newNext("something : ") == ("something ", "")
  assert newNext("something: ") == ("something", "")
  assert newNext("something:") == ("something", "")
  assert newNext("something") == ("something", "")