[FLINK-29707][cli] Fix possible comparator violation for "flink list"

[ferenc-csaky]

What is the purpose of the change

Fixes a comparator related bug for flink list, which can occur in JDK8. Probably fixed with JDK9, but I did not validated that.

Brief change log

Removed the custom comparator for JobStatusMessage and replaced it with a safe Comparator.comparing(...).

Verifying this change

If we put back the removed custom comparator, the updated test with the tricky data will fail.

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

[zentol]

I don't get how this can be JDK-specific. Probably related to overflows, no?

Is the test replicating the exact case you ran into?

[zentol]

The fix itself is fine though.

[flinkbot]

CI report:

• f4017d2 Azure: SUCCESS

Bot commands

The @flinkbot bot supports the following commands:

• @flinkbot run azure re-run the last Azure build

[ferenc-csaky]

I don't get how this can be JDK-specific. Probably related to overflows, no?

TBH I'm not sure anymore :) I did not debug it thoroughly, because of the easy fix. I went through this thread. It is not the same thing that happened here, there were mixed objects in the list in those cases and it was explicitly mentioned it works with the same object types.

Is the test replicating the exact case you ran into?

Yes.

[MartijnVisser]

@flinkbot run azure

[ferenc-csaky]

@flinkbot run azure

[mbalassi]

Since @ferenc-csaky made the test more concise (which was the most important concern) and @zentol already gave a 👍 on the logic I am merging this.