INCOMPLETE FCREPO-3931

[Surfrdan]

This PR is INCOMPLETE - Fixes for file extensions not being added to binaries when the -x arg is used

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**JIRA Ticket https://fedora-repository.atlassian.net/jira/software/c/projects/FCREPO/issues/FCREPO-3931?jql=project%20%3D%20%22FCREPO%22%20ORDER%20BY%20created%20DESC **:

What does this Pull Request do?

This PR attempts to fix an issue where file extensions were not being added to binary filenames within the dcfl-root when the user used the -x argument which is supposed to enable this feature. Whilst The PR does appear to fix this initial issue, I have struggled to get the tests to pass. This is mainly down to a lack of understanding of what some tests were trying to achieve.

Currently ArchiveGroupHandlerTest.filenameRemovedFromRelsInt is failing and I have made some changes to ArchiveGroupHandlerTest which may not be correct.

I need some clarity on the following questions:

What is filenameRemovedFromRelsInt trying to test? In what use-case would a filename be removed from RELS-INT?

What is the relationship between contentPath and filename within the fedora header?

How should this be tested?

• Read the changes to contentPath and filename handling within the fedora header to check whether they are being handled correctly
• Possibly, rebase ArchiveGroupHandlerTest to remove unwarranted modifications made by this PR
• Perform a migration with binaries in the following formats (logic from ArchiveGroupHandler:resolveFilename:405)

405     /**
 406      * Resolves the filename of the datastream based on the following precedence:
 407      *
 408      * 1. info:fedora/fedora-system:def/model#downloadFilename from RELS-INT
 409      * 2. LABEL from datastream meta
 410      * 3. Name of the datastream
 411      *
 412      * If extensions should be added, then an extension is picked based on the mime type. If the filename already
 413      * includes a `.` then no extension is added.
 414      *

Interested parties

Tag (@ mention) interested parties or, if unsure, @fcrepo/committers