Make it explicit that a DN can be used for ldap:check-user

Signed-off-by: Côme Chilliet <come.chilliet@nextcloud.com>

apps/user_ldap/lib/Access.php

@@ -488,7 +488,7 @@ class Access extends LDAPUtility {
 	/**
 	 * returns the internal Nextcloud name for the given LDAP DN of the user, false on DN outside of search DN or failure
 	 *
-	 * @param string $dn the dn of the user object
+	 * @param string $fdn the dn of the user object
 	 * @param string $ldapName optional, the display name of the object
 	 * @return string|false with with the name to use in Nextcloud
 	 * @throws \Exception
@@ -1770,7 +1770,7 @@ class Access extends LDAPUtility {
 	/**
 	 * @param string $dn
 	 * @param bool $isUser
-	 * @param null $ldapRecord
+	 * @param array|null $ldapRecord
 	 * @return false|string
 	 * @throws ServerNotAvailableException
 	 */

apps/user_ldap/lib/Command/CheckUser.php

@@ -64,7 +64,7 @@ class CheckUser extends Command {
 			->addArgument(
 					'ocName',
 					InputArgument::REQUIRED,
-					'the user name as used in Nextcloud'
+					'the user name as used in Nextcloud, or the LDAP DN'
 					 )
 			->addOption(
 					'force',
@@ -83,8 +83,14 @@ class CheckUser extends Command {
 
 	protected function execute(InputInterface $input, OutputInterface $output): int {
 		try {
-			$uid = $input->getArgument('ocName');
 			$this->assertAllowed($input->getOption('force'));
+			$uid = $input->getArgument('ocName');
+			if ($this->backend->getLDAPAccess($uid)->stringResemblesDN($uid)) {
+				$username = $this->backend->dn2UserName($uid);
+				if ($username !== false) {
+					$uid = $username;
+				}
+			}
 			$wasMapped = $this->userWasMapped($uid);
 			$exists = $this->backend->userExistsOnLDAP($uid, true);
 			if ($exists === true) {