fix: release record supplier lock on validation failure

[FrankChen021]

Root cause

checkOffsetAvailability acquired recordSupplierLock, then validated the record supplier assignment before entering the try/finally that releases the lock. If the assignment did not contain the expected stream partition, the validation threw IllegalStateException and permanently retained the reentrant lock on that thread.

Fix

Move the assignment validation into the existing try block so every path after successful lock acquisition reaches the finally and unlocks.

Add a focused regression test that exercises the assignment-mismatch exception and verifies that recordSupplierLock is no longer locked afterward.

Impact

This prevents a malformed or unexpectedly changed record-supplier assignment from leaking the supervisor's supplier lock and potentially blocking later record-supplier operations. Successful offset-availability checks and lock scope are unchanged.

Validation

• mvn -ntp -Pskip-static-checks -pl indexing-service -Dtest=SeekableStreamSupervisorStateTest test
  • 60 tests run; 0 failures; 0 errors; 0 skipped
• mvn -ntp -pl indexing-service -DskipTests checkstyle:check
  • 0 Checkstyle violations
• git diff --check

[Copilot]

Pull request overview

Fixes a lock-leak bug in SeekableStreamSupervisor#checkOffsetAvailability where recordSupplierLock could remain held if record-supplier assignment validation failed, potentially blocking later supervisor operations.

Changes:

• Moved record-supplier assignment validation inside the existing try/finally to guarantee recordSupplierLock.unlock() on all post-lock-acquisition paths.
• Added a targeted regression test that triggers the assignment-mismatch exception path and asserts the lock is released afterward.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
indexing-service/src/main/java/org/apache/druid/indexing/seekablestream/supervisor/SeekableStreamSupervisor.java	Ensures recordSupplierLock is always released even when assignment validation throws.
indexing-service/src/test/java/org/apache/druid/indexing/seekablestream/supervisor/SeekableStreamSupervisorStateTest.java	Adds a regression test covering the assignment-mismatch exception and lock-release behavior.

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[Copilot]

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated no new comments.

[FrankChen021]

I have reviewed the code for correctness, edge cases, concurrency, and integration risks; no issues found.

Reviewed 2 of 2 changed files.

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This is an automated review by Codex GPT-5.6-Sol