bug: null character not permitted in chr function

[andygrove]

Describe the bug

The following query ran without error in Spark but failed in Comet. I discovered this bug using Comet Fuzz.

SELECT chr(c9),chr(c4) FROM test0

Query failed in Comet: Job aborted due to stage failure: Task 13 in stage 83.0 failed 1 times, most recent failure: Lost task 13.0 in stage 83.0 (TID 749) (192.168.86.33 executor driver): org.apache.comet.CometNativeException: Execution error: null character not permitted.

Steps to reproduce

No response

Expected behavior

No response

Additional context

No response

[vaibhawvipul]

I am working on this.

[advancedxy]

I think the invalid input is 0, so datafusion refuses

> select chr(0);
Execution error: null character not permitted.

To be compatible with spark, we have to re implement chr in comet.

[vaibhawvipul]

I think the invalid input is 0, so datafusion refuses

> select chr(0);
Execution error: null character not permitted.

To be compatible with that, we have to re implement chr in comet.

Hey! I am able to repro this bug now. Thanks :)