AGG(DISTINCT x) beside an aggregate over an expression fails with Out of range [0x80000112] (3.4.2.5)

Version

• taosd version: 3.4.2.5.community (TDengine TSDB-OSS tarball)
• git: c15925333c9fe385902b153879b812c26bc612f7, build: Linux-arm64 2026-08-16 16:59:49
• Single dnode, stock taos.cfg, Ubuntu 24.04 aarch64

What happens

A query that mixes AGG(DISTINCT ...) with another aggregate whose argument is an expression rather than a bare column fails with Out of range [0x80000112]. Either aggregate on its own is fine, and the same pair with a bare column argument is fine. Three rows are enough to reproduce it, so this is not an actual overflow.

Reproduction

CREATE DATABASE t;
CREATE TABLE t.t2 (ts TIMESTAMP, n BIGINT, s VARCHAR(64));
INSERT INTO t.t2 VALUES
  (1700000000000, 1, 'aa') (1700000000001, 2, 'bbb') (1700000000002, 2, 'cccc');

Fails:

SELECT count(DISTINCT n), sum(length(s)) FROM t2   -> Out of range [0x80000112]
SELECT count(DISTINCT n), max(length(s)) FROM t2   -> Out of range [0x80000112]
SELECT count(DISTINCT n), count(length(s)) FROM t2 -> Out of range [0x80000112]
SELECT count(DISTINCT n), sum(abs(n)) FROM t2      -> Out of range [0x80000112]
SELECT count(DISTINCT n), sum(n+1) FROM t2         -> Out of range [0x80000112]
SELECT count(DISTINCT n), sum(length('abc')) FROM t2 -> Out of range [0x80000112]
SELECT sum(DISTINCT n), sum(length(s)) FROM t2     -> Out of range [0x80000112]

Succeeds:

SELECT count(DISTINCT n) FROM t2                   -> 2
SELECT sum(length(s)) FROM t2                      -> 9
SELECT count(DISTINCT n), sum(n) FROM t2           -> 2 | 5
SELECT count(DISTINCT n), avg(n), sum(n) FROM t2   -> 2 | 1.666.. | 5
SELECT count(DISTINCT abs(n)), sum(n) FROM t2      -> 2 | 5

So the trigger is narrow and consistent: a DISTINCT aggregate co-located with a non-DISTINCT aggregate over a function call or arithmetic expression. An expression inside the DISTINCT aggregate itself is fine (count(DISTINCT abs(n))), and a constant argument still trips it (sum(length('abc'))), which points at the co-location handling rather than at any value being out of range.

Wrapping the source in a subquery does not help:

SELECT count(DISTINCT n), sum(length(s)) FROM (SELECT n, s FROM t2)
    -> Out of range [0x80000112]

Expected

Both aggregates evaluated, as the documentation for DISTINCT aggregation allows: "A single query may mix DISTINCT and non-DISTINCT aggregates".

Why we ran into it

Found while adding TDengine to ClickBench. None of the benchmark's final queries hit it, but it came up while translating them and cost some time to pin down, because Out of range reads like a data problem rather than a planner one.