[tests-only] Ensure that path is a string in makeDavRequest

[phil-davis]

Description

When running the test-runner with PHP 8.1 (against an oC10 system running PHP 7.4) we get:
https://drone.owncloud.com/owncloud/core/36003/82/13

runsh: Total unexpected failed scenarios throughout the test run:
apiWebdavOperations/search.feature:273
apiWebdavOperations/search.feature:289
apiWebdavOperations/search.feature:314

    When user "Alice" searches for resources tagged with tag "JustARegularTag1" using the webDAV API # TagsContext::userSearchesForTagUsingWebDavAPI()
      Type error: str_replace(): Argument #3 ($subject) must be of type array|string, null given (Behat\Testwork\Call\Exception\FatalThrowableError)

Some code passes path=null to WebDavHelper::makeDavRequest, which is allowed. If path is null, then set it to the empty string, so that later uses of path, like str_replace will not complain about a type error.

How Has This Been Tested?

CI - PR #40127 demonstrates that this code fixed the problem.

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Database schema changes (next release will require increase of minor version instead of patch)
• Breaking change (fix or feature that would cause existing functionality to change)
• Technical debt
• Tests only (no source changes)

Checklist:

• Code changes
• Unit tests added
• Acceptance tests added
• Documentation ticket raised:
• Changelog item, see TEMPLATE

[sonarqubecloud]

Kudos, SonarCloud Quality Gate passed!   

0 Bugs
0 Vulnerabilities
0 Security Hotspots
0 Code Smells

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[individual-it]

what if its bool or int or something else?
shouldn't $path = (string)$path; do it for all cases

[phil-davis]

what if its bool or int or something else? shouldn't $path = (string)$path; do it for all cases

The parameter is declared ?string in the function definition. So PHP will already "explode" if anything other than null or a string is passed in.