GH-1194: Preserve empty list offset buffers - #1229
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July 15, 2026 02:03
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Could a maintainer please add the |
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could you please take a look at it? thanks! |
| ArrowBuf oldOffsetBuffer = offsetBuffer; | ||
| offsetBuffer = allocateOffsetBuffer(requiredCapacity); | ||
| offsetBuffer.setBytes( | ||
| 0, oldOffsetBuffer, 0, Math.min(oldOffsetBuffer.capacity(), requiredCapacity)); |
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If requiredCapacity exceeds oldOffsetBuffer.capacity(), the remaining offset entries cannot be left uninitialized or zeroed — per the Arrow spec the offset buffer must be monotonically non-decreasing, so unfilled entries must be set to the last copied offset value to represent empty lists at those positions.
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What's Changed
Preserve the required one-entry offset buffer for empty
ListVectorandLargeListVectorinstances when setting value count and when splitting/transferring zero values. This keeps empty list vectors aligned with the Arrow offset-buffer invariant and avoids exposing buffers whose writer index exceeds capacity.Adds regression coverage for allocated, unallocated, split-and-transfer, and nested empty list vectors.
Closes #1194.
Tests:
mvn -pl vector -am -P=-error-prone -Dmaven.gitcommitid.skip=true -Dsurefire.failIfNoSpecifiedTests=false -Dtest=TestSplitAndTransfer,TestListVector,TestLargeListVector testmvn -P=-error-prone -Dmaven.gitcommitid.skip=true test