Bug: Exception on empty cookie header

[neunzehnhundert97]

Hi,

I just found an odd behaviour of requests-scala. When using the library to call the Spotify API, it throws the following exception:

Caused by: java.lang.IllegalArgumentException: Empty cookie header string
	at java.base/java.net.HttpCookie.parseInternal(HttpCookie.java:839)
	at java.base/java.net.HttpCookie.parse(HttpCookie.java:210)
	at java.base/java.net.HttpCookie.parse(HttpCookie.java:186)
	at requests.Response.$anonfun$cookies$2(Model.scala:205)
	at scala.collection.Iterator$$anon$10.nextCur(Iterator.scala:585)
	at scala.collection.Iterator$$anon$10.hasNext(Iterator.scala:599)
	at scala.collection.Iterator$$anon$9.hasNext(Iterator.scala:574)
	at scala.collection.mutable.Growable.addAll(Growable.scala:64)
	at scala.collection.mutable.Growable.addAll$(Growable.scala:60)
	at scala.collection.immutable.MapBuilderImpl.addAll(Map.scala:692)
	at scala.collection.immutable.Map$.from(Map.scala:643)
	at scala.collection.IterableOnceOps.toMap(IterableOnce.scala:1256)
	at scala.collection.IterableOnceOps.toMap$(IterableOnce.scala:1255)
	at scala.collection.AbstractIterator.toMap(Iterator.scala:1279)
	at requests.Response.<init>(Model.scala:207)
	at requests.Requester.apply(Requester.scala:122)

Below the (in my eyes) relevant part of scala-requests code (Model.scala, lines 201 - 207):

  val cookies: Map[String, HttpCookie] = history.toSeq.flatMap(_.cookies).toMap ++ headers
    .get("set-cookie")
    .iterator
    .flatten
    .flatMap(java.net.HttpCookie.parse(_).asScala) // Line 205, where the exception happens
    .map(x => x.getName -> x)
    .toMap

Debugging shows that the response, which triggers this problem, has set the "set-cookie" header, but with no contents. I guess using a filter to get rid of empty strings should solve the problem.