RFR: 8263899: HttpClient throws NPE in AuthenticationFilter when parsing www-authenticate head [v2]

[Michael McMahon]

> Could I get the following simple fix reviewed please?
> 
> Thanks,
> Michael.

Michael McMahon has updated the pull request with a new target base due to a merge or a rebase. The incremental webrev excludes the unrelated changes brought in by the merge/rebase. The pull request contains four additional commits since the last revision:

 - updated test comment
 - Merge branch 'master' into 8263899
 - changed test to use ephemeral port
 - Initial fix

-------------

Changes:
  - all: https://git.openjdk.java.net/jdk/pull/3113/files
  - new: https://git.openjdk.java.net/jdk/pull/3113/files/8152396a..54113f60

Webrevs:
 - full: https://webrevs.openjdk.java.net/?repo=jdk&pr=3113&range=01
 - incr: https://webrevs.openjdk.java.net/?repo=jdk&pr=3113&range=00-01

  Stats: 12326 lines in 335 files changed: 5525 ins; 4652 del; 2149 mod
  Patch: https://git.openjdk.java.net/jdk/pull/3113.diff
  Fetch: git fetch https://git.openjdk.java.net/jdk pull/3113/head:pull/3113

PR: https://git.openjdk.java.net/jdk/pull/3113