Fix NPE on a recursive property reference in a list field - #13099
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renechoi wants to merge 1 commit into
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Fix NPE on a recursive property reference in a list field#13099renechoi wants to merge 1 commit into
renechoi wants to merge 1 commit into
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DefaultModelInterpolator records an ERROR and returns null when the interpolator throws on a recursive variable reference. The generated transformer stores that null in List<String> model fields such as build/filters, whose Properties sibling branch already guards against it, and the immutable model constructor then copies the list with List.copyOf. The build fails with a bare NullPointerException instead of the "recursive variable reference" error that was just collected. Return the original text instead, which is what the Properties branch and StringVisitorModelInterpolator (MNG-8174) already do. The returned instance is identical, so the transformer's newVal != oldVal check stays false and unaffected models are still returned unchanged.
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Clean, minimal fix. Returning the original text on an InterpolatorException instead of null is the correct approach — the error is already collected in the problem collector, and the build will fail with a clear "recursive variable reference" message. Returning null caused a secondary NullPointerException in List.copyOf() that masked the real error.
Consistent with DecryptingSettingsTransformer and the Maven 3 fix (MNG-8174 / #12932).
Test covers the exact failure path: recursive properties in a List<String> model field (build/filters).
📋 PR Metadata
| Aspect | Current | Suggested |
|---|---|---|
| Category | (unlabeled) | bug |
| Labels | (none) | + bug |
| Milestone | (none) | 4.1.0 |
🔀 Backport Status
master but no backport PRs were found for:
maven-4.0.x— no backport PR found (author mentions willingness to open one)
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On a recursive reference
DefaultModelInterpolatorrecords an ERROR and returnsnull. The transformer writes it intoList<String>fields such asbuild/filters(itsPropertiesbranch already guards), and the immutable constructor callsList.copyOf, so the build dies with a bare NPE that hides the collected error:Returning the original text fixes it at the source instead of in the generated template, and matches
DecryptingSettingsTransformerand MNG-8174 (#12932), which covered Maven 3 only.The new test fails on master with that NPE. Full
mvn test: 3136 tests, 0 failures. Can open amaven-4.0.xbackport.