RFR: 8304837: Classfile API throws IOOBE for MethodParameters attribute without parameter names

Thu Mar 23 20:18:16 UTC 2023

After merging master into https://github.com/openjdk/jdk/pull/9862, we encountered test failures (e.g., https://github.com/SirYwell/jdk/actions/runs/4500940829/jobs/7923018438#step:9:2541). The Classfile API tries to read from constant pool index 0 if a MethodParameters attribute has an entry without name.

The fix is simply using `readUtf8EntryOrNull` instead of `readUtf8Entry`. The related code already correctly handles nullability.

I didn't find an appropriate test class so I added a new one. Let me know if there's a better place or if the test can be improved somehow.

As I don't have a JBS account, someone needs to create a bug report there for me. Thanks.

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Commit messages:
 - Read parameter name from constant pool optionally

Changes: https://git.openjdk.org/jdk/pull/13167/files
 Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13167&range=00
  Issue: https://bugs.openjdk.org/browse/JDK-8304837
  Stats: 72 lines in 2 files changed: 70 ins; 0 del; 2 mod
  Patch: https://git.openjdk.org/jdk/pull/13167.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/13167/head:pull/13167

PR: https://git.openjdk.org/jdk/pull/13167