Regression on isConstant(trim('')) between 25.1.8.25 and 25.2.2.39

[jrogov]

Company or project name

No response

Describe what's wrong

Hello 👋

When implementing a decoding UDF, I've noticed a regression on query analysis of a result of trim string function as constant that was included somewhere between releases 25.1.8.25 and 25.2.2.39.

Is this expected?

Does it reproduce on the most recent release?

Yes

How to reproduce

$ docker run clickhouse:25.1.8.25 clickhouse-local "SELECT isConstant(trimBoth(''))"
1
$ docker run clickhouse:25.2.2.39 clickhouse-local "SELECT isConstant(trimBoth(''))"
0

Latest release (25.3.2.39 at the time of writing) has it as well:

$ drun clickhouse:25.3.2.39 clickhouse-local "SELECT isConstant(trimBoth(''))"
0

Expected behavior

No response

Error message and/or stacktrace

No response

Additional context

No response

[wxybear]

Maybe there is just a function missing in the code that has no override, I'd like to fix it

[SaltTan]

• Fix behavior of TRIM with computed trim characters #75399

[azat]

@rschu1ze there is one more "regression" after #75399, maybe you can also take a look?