8292955: Collections.checkedMap Map.merge does not properly check key and value

[cost0much]

Clean backport. This ensures Collections.checkedMap Map.merge fails when key value types don't match. Affected test on linux x64 and GHA passes.

I'm not entirely sure if this would be a good backport, given that this would change the behavior in the scenario of a failed type mismatch. Nevertheless, I wanted to submit a request to check whether these type of backports are acceptable.

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Progress

• Change must not contain extraneous whitespace
• JDK-8292955 needs maintainer approval
• Commit message must refer to an issue

Issue

• JDK-8292955: Collections.checkedMap Map.merge does not properly check key and value (Bug - P4 - Requested)

Reviewing

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$ git fetch https://git.openjdk.org/jdk21u-dev.git pull/1730/head:pull/1730
$ git checkout pull/1730

Update a local copy of the PR:
$ git checkout pull/1730
$ git pull https://git.openjdk.org/jdk21u-dev.git pull/1730/head

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$ git pr checkout 1730

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https://git.openjdk.org/jdk21u-dev/pull/1730.diff

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[bridgekeeper]

👋 Welcome back cost0much! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[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]

⚠️ @cost0much 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.

[mlbridge]

Webrevs

• 00: Full (7acda94c)

[cost0much]

/approval request Fixes Collections.checkedMap Map.merge to check for key value types. Applies cleanly and patched in JDK23. The change passes the affected test and GHA checks. The risk is medium because Collections is a central class and this will change program behavior.

[openjdk]

@cost0much
8292955: The approval request has been created successfully.