fix(occ): pass empty string instead of null to user search in home list commands

[DeepDiver1975]

Summary

occ user:home:list-dirs (and user:home:list-users --all) crash on PHP 8 with:

TypeError: OC\DB\Connection::escapeLikeParameter(): Argument #1 ($param)
must be of type string, null given

Root cause

Both commands passed null as the search pattern to IUserManager::search() to mean "all users":

• core/Command/User/HomeListDirs.php:55 — search(null)
• core/Command/User/HomeListUsers.php:82 — search(null, null, null, true)

The null flows through Manager::search() → AccountMapper::search() → Connection::escapeLikeParameter(string $param). On older PHP it was silently coerced to ''; PHP 8's strict scalar type hint rejects it and raises a TypeError. (The Docker reference in the issue is incidental — it's a PHP-version difference, not a container one.)

The correct "match all" sentinel is the empty string '', which UserSearch::isSearchable() explicitly treats as searchable and which every other caller in the codebase already uses (ListUsers, ScanFiles, Scan, Principal).

Fix

Pass '' instead of null at both call sites.

Tests

Updated HomeListDirsTest and HomeListUsersTest to assert the search pattern is identicalTo('') (strict — loose with('') would pass against null since '' == null in PHP). Both tests fail against the old code and pass after the fix.

Fixes #41630

🤖 Generated with Claude Code

[phil-davis]

In places like:
https://github.com/owncloud/core/blob/master/lib/private/User/Manager.php#L285

	/**
	 * search by user id
	 *
	 * @param string $pattern
	 * @param int $limit
	 * @param int $offset
	 * @param bool $alwaysReturnAllMatches
	 * @return \OC\User\User[]
	 */
	public function search($pattern, $limit = null, $offset = null, $alwaysReturnAllMatches = false) {

Should we specify the types?
$pattern has to be a string, and passing null here was an early part of the problem.

Or does that lead us down a whole rabbit-warren of implementing full parameter and return type declarations across the codebase?!

[DeepDiver1975]

Or does that lead us down a whole rabbit-warren of implementing full parameter and return type declarations across the codebase?!

this is what I am fearing ..... I'd push back such code cleanup for the time being ....