8292043: Incorrect decoding near EOF for stateful decoders like UTF-16

[rm-gh-8]

Backporting JDK-8292043: Incorrect decoding near EOF for stateful decoders like UTF-16. Fixes incorrect state handling with EOF in StreamDecoder. There's a reset() call to the decoder seeing the EOF before the last decode() operation to handle the state correctly. Removing the call should not affect other cases because reset() is issued down the execution.

Also adds a new test. Ran GHA Sanity Checks (passed) and new test (passed). Patch is clean.

---

Progress

• Change must not contain extraneous whitespace
• Commit message must refer to an issue
• JDK-8292043 needs maintainer approval

Issue

• JDK-8292043: Incorrect decoding near EOF for stateful decoders like UTF-16 (Bug - P4 - Requested)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk17u-dev.git pull/4177/head:pull/4177
$ git checkout pull/4177

Update a local copy of the PR:
$ git checkout pull/4177
$ git pull https://git.openjdk.org/jdk17u-dev.git pull/4177/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 4177

View PR using the GUI difftool:
$ git pr show -t 4177

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk17u-dev/pull/4177.diff

Using Webrev

Link to Webrev Comment

[bridgekeeper]

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[openjdk]

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

This backport pull request has now been updated with issue from the original commit.

[openjdk]

⚠️ @rm-gh-8 This change is now ready for you to apply for maintainer approval. This can be done directly in each associated issue or by using the /approval command.

[rm-gh-8]

/approval request for backport of JDK-8292043: Incorrect decoding near EOF for stateful decoders like UTF-16.

Ran the updated and related tests on linux-x64, linux-aarch64, macos-aarch64 and windows-x64:

(All Passed) - make test TEST=test/jdk/java/io/InputStreamReader

Results are attached.
linux-aarch64-specific-test.log
linux-x64-specific-test.log
macos-aarch64-specific-test.log
windows-x64-specific-test.log

[openjdk]

@rm-gh-8
8292043: The approval request has been created successfully.

[mlbridge]

Webrevs

• 00: Full (62bbf4c3)