8263506: Make sun.net.httpserver.UnmodifiableHeaders unmodifiable

[FrauBoes]

The fix makes the map in sun.net.httpserver.UnmodifiableHeaders unmodifiable by wrapping it in an unmodifiable view.

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Progress

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Issue

• JDK-8263506: Make sun.net.httpserver.UnmodifiableHeaders unmodifiable

Reviewers

• Michael McMahon (@Michael-Mc-Mahon - Reviewer) ⚠️ Review applies to 8981b44
• Daniel Fuchs (@dfuch - Reviewer)

Reviewing

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[bridgekeeper]

👋 Welcome back jboes! 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]

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[mlbridge]

Webrevs

• 05: Full - Incremental (6fce0d2d)
• 04: Full - Incremental (4f2247fc)
• 03: Full - Incremental (ee8da732)
• 02: Full - Incremental (8981b444)
• 01: Full - Incremental (fcdfb18)
• 00: Full (93b88fc)

[dfuch]

The changes LGTM. What about modifying ExchangeImpl to create the UnmodifiableHeaders in its constructor, instead of creating a new instance every time getRequestHeaders() is called?

[Michael-Mc-Mahon]

Could you add a comment here that Headers is mutable, but no reference to it escapes.

Also, can you fix the indentation of the other existing methods.

[dfuch]

LGTM

[openjdk]

@FrauBoes This change now passes all automated pre-integration checks.

ℹ️ This project also has non-automated pre-integration requirements. Please see the file CONTRIBUTING.md for details.

After integration, the commit message for the final commit will be:

8263506: Make sun.net.httpserver.UnmodifiableHeaders unmodifiable

Reviewed-by: michaelm, dfuchs

You can use pull request commands such as /summary, /contributor and /issue to adjust it as needed.

At the time when this comment was updated there had been 4 new commits pushed to the master branch:

• d3fdd73: 8264173: [s390] Improve Hardware Feature Detection And Reporting
• 9d65039: 8263984: Invalidate printServices when there are no printers
• adb860e: 8255800: Raster creation methods need some specification clean up
• eab8455: 8261137: Optimization of Box nodes in uncommon_trap

Please see this link for an up-to-date comparison between the source branch of this pull request and the master branch.
As there are no conflicts, your changes will automatically be rebased on top of these commits when integrating. If you prefer to avoid this automatic rebasing, please check the documentation for the /integrate command for further details.

➡️ To integrate this PR with the above commit message to the master branch, type /integrate in a new comment.

[Michael-Mc-Mahon]

LGTM

[FrauBoes]

I included a null check in the constructor to account for null values of List<String>, which Headers allows. Fixed the indentation.

Testing: Tier 1-3 all clear.

[FrauBoes]

It turns out I wasn't right in the last commit. The null check is not needed in the constructor, but in the get method, where Headers::get can return null, which can cause Collections.unmodifiableList to throw NPE. I updated the get method and added some more test cases to confirm equality of Headers and UnmodifiableHeaders instances.

Testing: Tier 1-3 all clear.

[Michael-Mc-Mahon]

Latest changes LGTM.

[FrauBoes]

/integrate

[openjdk]

@FrauBoes Since your change was applied there have been 18 commits pushed to the master branch:

• af13c64: 8264711: More runtime TRAPS cleanups
• 3aec2d9: 8264718: Shenandoah: enable string deduplication during root scanning
• 255afbe: 8264672: runtime/ParallelLoad/ParallelSuperTest.java timed out
• ec599da: 8264633: Add missing logging to PlatformRecording#stop
• e89542f: 8264352: AArch64: Optimize vector "not/andNot" for NEON and SVE
• 016db40: 8263907: Specification of CellRendererPane::paintComponent(..Rectangle) should clearly mention which method it delegates the call to
• 78d1164: 8214455: Relocate CDS archived regions to the top of the G1 heap
• 88eb291: 8264809: test-lib fails to build due to some warnings in ASN1Formatter and jfr
• a863ab6: 8264551: Unexpected warning when jpackage creates an exe
• 6e2b82a: 8264731: Introduce InstanceKlass::method_at_itable_or_null()
• ... and 8 more: https://git.openjdk.java.net/jdk/compare/92fad1b4088ca6c7738bfe9c95da15249f40ef74...master

Your commit was automatically rebased without conflicts.

Pushed as commit 214d6e2.

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