Fix FunctionVariantAdaptor exception when nested function returns Nothing type#97213
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alexey-milovidov merged 3 commits intomasterfrom Feb 18, 2026
Merged
Fix FunctionVariantAdaptor exception when nested function returns Nothing type#97213alexey-milovidov merged 3 commits intomasterfrom
alexey-milovidov merged 3 commits intomasterfrom
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…hing type When `FunctionVariantAdaptor` executes a function on a Variant column that contains a single variant (e.g., `Array(Nothing)` from an empty array literal `[]`), the nested function can return a result of type `Nothing`. The code only checked for `Nullable(Nothing)` via `onlyNull` but missed plain `Nothing`, causing a failed cast to the expected `Variant(...)` result type and a `LOGICAL_ERROR` exception. Add `isNothing` checks alongside existing `onlyNull` checks in all three execution paths (single variant no NULLs, single variant with NULLs, multiple variants) to treat `Nothing` results as defaults/NULLs. https://s3.amazonaws.com/clickhouse-test-reports/json.html?REF=master&sha=42be5daa2cfd617b45ee36eeec6d72fd405fba41&name_0=MasterCI&name_1=AST%20fuzzer%20%28amd_debug%29 Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
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Looks reasonable. |
bharatnc
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Feb 17, 2026
…ot support Variant type inference in UNION ALL Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
This was referenced Feb 18, 2026
robot-clickhouse
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Feb 18, 2026
Cherry pick #97213 to 26.1: Fix FunctionVariantAdaptor exception when nested function returns Nothing type
robot-clickhouse
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…sted function returns Nothing type
clickhouse-gh bot
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Feb 18, 2026
Backport #97213 to 26.1: Fix FunctionVariantAdaptor exception when nested function returns Nothing type
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Summary
LOGICAL_ERRORexception inFunctionVariantAdaptorwhen a nested function returnsNothingtype (e.g.,arrayElementonArray(Nothing)from an empty array literal[]in aUNION ALLwith Variant arrays)isNothingchecks alongside existingonlyNullchecks in all three execution paths to treatNothingresults as defaults/NULLsCI report: https://s3.amazonaws.com/clickhouse-test-reports/json.html?REF=master&sha=42be5daa2cfd617b45ee36eeec6d72fd405fba41&name_0=MasterCI&name_1=AST%20fuzzer%20%28amd_debug%29
Test plan
03918_variant_adaptor_nothing_typeclickhouse-localusing both simplified and original fuzzer queriesChangelog category (leave one):
Changelog entry (a user-readable short description of the changes that goes into CHANGELOG.md):
Fix
LOGICAL_ERRORexception inFunctionVariantAdaptorwhen a function operating on Variant columns returnsNothingtype, which can happen with empty arrays inUNION ALLqueries.🤖 Generated with Claude Code