incorrect treatment of multiple informational HTTP responses

[reschke]

NOTE: this is not the same as #7440.

From https://github.com/greenbytes/java-http-1xx-tests:

mvn clean install -Dtest=OkHttpClientTests

Responses that contain multiple 1xx messages are treated incorrectly:

[ERROR] testOkHttpClient104_100(org.greenbytes.http.test1xx.OkHttpClientTests)  Time elapsed: 0.459 s  <<< ERROR!
java.lang.IllegalStateException: state: 3
        at org.greenbytes.http.test1xx.OkHttpClientTests.testOkHttpClient(OkHttpClientTests.java:20)
        at org.greenbytes.http.test1xx.OkHttpClientTests.testOkHttpClient104_100(OkHttpClientTests.java:63)

[ERROR] testOkHttpClient104_2(org.greenbytes.http.test1xx.OkHttpClientTests)  Time elapsed: 0.006 s  <<< ERROR!
java.lang.IllegalStateException: state: 3
        at org.greenbytes.http.test1xx.OkHttpClientTests.testOkHttpClient(OkHttpClientTests.java:20)
        at org.greenbytes.http.test1xx.OkHttpClientTests.testOkHttpClient104_2(OkHttpClientTests.java:58)

[yschimke]

Thanks for the great repro.

[reschke]

It's my pleasure :-)

[yschimke]

I put together a test and minimal fix. It feels too easy, so I'd love a review.