Hi, Please find enclosed a patch that solves an unexpected interaction between server-set cookies and user-set cookies in the `java.net.HttpClient`.
In JDK 12 we fixed [JDK-8213189](https://bugs.openjdk.java.net/browse/JDK-8213189) to allow user-supplied header to take precedence over (that is, replace) system-headers. At the time the fact that server cookies would be added to the system-supplied headers by the `CookieHandler` (if present), and that a user-supplied cookie would therefore replace them (instead of simply appending to them) was overlooked. This fix proposes to restore the behavior of JDK 11 WRT to cookies - and arrange for user-supplied cookies to be appended to server-supplied cookies. ------------- Commit messages: - Updated tests - 8276774: Cookie stored in CookieHandler not sent if user headers contain cookie Changes: https://git.openjdk.java.net/jdk/pull/6408/files Webrev: https://webrevs.openjdk.java.net/?repo=jdk&pr=6408&range=00 Issue: https://bugs.openjdk.java.net/browse/JDK-8276774 Stats: 70 lines in 4 files changed: 33 ins; 14 del; 23 mod Patch: https://git.openjdk.java.net/jdk/pull/6408.diff Fetch: git fetch https://git.openjdk.java.net/jdk pull/6408/head:pull/6408 PR: https://git.openjdk.java.net/jdk/pull/6408
