What is the purpose of the change

The PR is to fixStackOverflow for queries like

SELECT coalesce(SELECT invalid);

Brief change log

The way howStackOverflow appears:

1. Validation reachedSqlValidatorImpl#validateNamespace
2. At some point deeper in stack it reachesSqlValidatorImpl#inferUnknownTypes
3. In case of functions (in this casecoalesce) it invokes Flink'sTypeInferenceOperandInference#inferOperandTypes
4. Then deeper it fails inDelegatingScope#fullyQualify withColumn 'invalid' not found in any table
5. Now the problem is that this failure is swallowed in bullet 3.
6. Thus instead of failing the whole validation it continues endlessly failing and swallowing the error.

Verifying this change

There are tests added

Does this pull request potentially affect one of the following parts:

• Dependencies (does it add or upgrade a dependency): (no)
• The public API, i.e., is any changed class annotated with@Public(Evolving): ( no)
• The serializers: (no)
• The runtime per-record code paths (performance sensitive): (no)
• Anything that affects deployment or recovery: JobManager (and its components), Checkpointing, Kubernetes/Yarn, ZooKeeper: (no)
• The S3 file system connector: (no)

Documentation

• Does this pull request introduce a new feature? (no)
• If yes, how is the feature documented? (not applicable)