[victor6567758]

Summary

Backport of two upstream Gandiva fixes to dremio_27.0_26_20 (Arrow 26.0.0), one commit each.

1. apache/arrow#55278 — apacheGH-55277, decimal return slots

Files: cpp/src/gandiva/decimal_ir.cc, decimal_ir.h, tests/decimal_test.cc.

2. apache/arrow#55282 — apacheGH-55281, per-row arena release

Files: cpp/src/gandiva/execution_context.h, simple_arena.h, llvm_generator.cc, tests/projector_test.cc, tests/test_util.cc, tests/test_util.h.

Testing

Built locally (gcc 15, Debug, ARROW_GANDIVA=ON) and ran:

• gandiva-projector-test --gtest_filter=TestDecimal.CastLargeBatch — pass
• gandiva-projector-test --gtest_filter=TestProjector.TestLevenshteinArenaGrowth:TestProjector.TestNestedStringFunctionArenaGrowth:TestProjector.TestExtendedCFunctionArenaGrowth — pass
• full gandiva-projector-test (covers both PRs' test files) — pass
• gandiva-precompiled-test — 131/132 pass; TestTime.TestCastTimestampWithTZ fails, pre-existing on the base branch and unrelated (neither PR touches precompiled/)
• Tested this build with master Dremio branch and confirm the issue is fixed

DX-128210

[lriggs]

It would probably be good to build jars and run a Dremio pr with the arrow jar change for basic tests. Not strictly necessary but it will provide additional testing. I usually do that when making any substantial changes.

[victor6567758]

It would probably be good to build jars and run a Dremio pr with the arrow jar change for basic tests. Not strictly necessary but it will provide additional testing. I usually do that when making any substantial changes.

@lriggs tested this build with Dremio confirm it is fixed, updated Summary, see https://dremio.atlassian.net/browse/DX-128210