RFR: 8352502: Response message is null if expect 100 assertion fails with non 100 [v3]

[Daniel Fuchs]

On Thu, 10 Jul 2025 13:28:26 GMT, Darragh Clarke <dclarke at openjdk.org> wrote:

>> Currently if a request has set Expect-Continue and receives a non 100 response the `responseMessage` wouldn't be set.
>> 
>> This PR sets `responseMessage`, it also updates `getResponseMessage` to check if the message has already been set. This should match the way that `responseCode` is currently handled.
>> 
>> I also added a test to cover some possible responses.
>
> Darragh Clarke has updated the pull request incrementally with one additional commit since the last revision:
> 
>   adding salting and path verification to test

Marked as reviewed by dfuchs (Reviewer).

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

PR Review: https://git.openjdk.org/jdk/pull/25999#pullrequestreview-3088574176