[Go][Parquet] Fix FixedSizeList nullable elements read as NULL - #585
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The FIXED_SIZE_LIST case in pathBuilder.Visit was missing the nullableInParent assignment that the LIST case has. This caused child values to be encoded with incorrect definition levels, resulting in non-null values being read back as NULL. Fixes: apache#584
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zeroshade
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Nov 30, 2025
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Thanks for this! And for the test!
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…pes (#586) ## Summary - Extracts common logic for LIST, MAP, and FIXED_SIZE_LIST into a shared `visitListLike` helper function - Ensures `nullableInParent` is always set correctly before visiting child values, making it impossible to forget this step when adding new list-like type handling - Uses `defLevelOffset` parameter to calculate `defLevelIfEmpty` after all increments ## Rationale This refactoring follows the principle of "making invalid states unrepresentable". The original bug in #584 (fixed in #585) was caused by the FIXED_SIZE_LIST case forgetting to set `nullableInParent`. By extracting the common pattern into a helper function, future additions of list-like types cannot omit this critical step. ## Test plan - [x] All existing tests pass - [x] Regression test from #585 (`TestFixedSizeListNullableElements`) continues to pass 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-authored-by: Claude <noreply@anthropic.com>
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Fixes #584
The
FIXED_SIZE_LISTcase inpathBuilder.Visitwas missing thenullableInParentassignment that theLISTcase has, causing non-null values to be read back as NULL.Fix: Add one line to set
nullableInParentbefore visiting child values.Test: Added
TestFixedSizeListNullableElementsroundtrip test.