map_from_arrays() with NULL inputs causes native crash

[andygrove]

Description

Calling map_from_arrays(NULL, NULL) through Comet's native execution on table data causes a crash with:

map key cannot be null

Spark returns NULL for map_from_arrays(NULL, NULL).

Steps to Reproduce

CREATE TABLE test_map(k array<string>, v array<int>) USING parquet;
INSERT INTO test_map VALUES (NULL, NULL);
SELECT map_from_arrays(k, v) FROM test_map;

Expected Behavior

Should return NULL, matching Spark behavior.

Actual Behavior

Native execution crashes with "map key cannot be null".

🤖 Generated with Claude Code

[kazantsev-maksim]

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