Iceberg Rest Catalog: Fix bug where listing namespaces was performed but non-existing namespace was provided

[amogh-jahagirdar]

Fix bug where listing namespaces was performed but non-existing namespace was provided. This is coming from discussion on #19818 #19818 (comment)

Description

This change fixes a bug where if an explicit namespace was provided the listTables implementation would do a full listing of the all the namespaces even if the namespace does not exist at the time.

Additional context and related issues

Release notes

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# Section
* Fix bug where listing namespaces was performed but non-existing namespace was provided.  This applies when listing tables.

[cla-bot]

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[amogh-jahagirdar]

I submitted my CLA yesterday, should take a few days. @findepi before we merge it would be great to get @danielcweeks input on this, want to make sure that the original implementation wasn't intentional.

[cla-bot]

Thank you for your pull request and welcome to the Trino community. We require contributors to sign our Contributor License Agreement, and we don't seem to have you on file. Continue to work with us on the review and improvements in this PR, and submit the signed CLA to cla@trino.io. Photos, scans, or digitally-signed PDF files are all suitable. Processing may take a few days. The CLA needs to be on file before we merge your changes. For more information, see https://github.com/trinodb/cla

[danielcweeks]

LGTM. I think this issue was unintentionally introduced when adding support for listing all namespaces when the namespace was provided. Good catch.

[amogh-jahagirdar]

Looks like an unrelated test is failing:

| 53f8cacad1c34c54a089985820c1df72 | suite-8-non-generic | singlenode-hive-acid | config-default |      {} | FAILED |  31.15m | Tests exited with code 1 |

[amogh-jahagirdar]

Rebased:

It still looks like 2 other unrelated Hive tests are failing:

 TestHiveMerge > testMergeMultipleRowsMatchFails(0: CREATE TABLE %s (customer STRING, purchases INT, address STRING) STORED AS ORC TBLPROPERTIES ('transactional'='true')) [groups: hive_transactional] 

 TestHiveTransactionalTable > testReadFullAcidPartitioned [groups: hive_transactional]