fix documentation, get and createGroup may return null

* also have stricter checks in place

Signed-off-by: Arthur Schiwon <blizzz@arthur-schiwon.de>

core/Command/Group/Add.php

@@ -68,6 +68,10 @@ class Add extends Base {
 			return 1;
 		} else {
 			$group = $this->groupManager->createGroup($gid);
+			if($group === false) {
+				$output->writeln('<error>Could not create group</error>');
+				return 2;
+			}
 			$output->writeln('Created group "' . $group->getGID() . '"');
 
 			$displayName = trim((string) $input->getOption('display-name'));

core/Command/User/Add.php

@@ -25,6 +25,7 @@
 namespace OC\Core\Command\User;
 
 use OC\Files\Filesystem;
+use OCP\IGroup;
 use OCP\IGroupManager;
 use OCP\IUser;
 use OCP\IUserManager;
@@ -152,10 +153,14 @@ class Add extends Command {
 			if (!$group) {
 				$this->groupManager->createGroup($groupName);
 				$group = $this->groupManager->get($groupName);
-				$output->writeln('Created group "' . $group->getGID() . '"');
+				if($group instanceof IGroup) {
+					$output->writeln('Created group "' . $group->getGID() . '"');
+				}
+			}
+			if($group instanceof IGroup) {
+				$group->addUser($user);
+				$output->writeln('User "' . $user->getUID() . '" added to group "' . $group->getGID() . '"');
 			}
-			$group->addUser($user);
-			$output->writeln('User "' . $user->getUID() . '" added to group "' . $group->getGID() . '"');
 		}
 	}
 }

lib/private/Group/Manager.php

@@ -163,7 +163,7 @@ class Manager extends PublicEmitter implements IGroupManager {
 
 	/**
 	 * @param string $gid
-	 * @return \OC\Group\Group
+	 * @return IGroup|null
 	 */
 	public function get($gid) {
 		if (isset($this->cachedGroups[$gid])) {
@@ -175,7 +175,7 @@ class Manager extends PublicEmitter implements IGroupManager {
 	/**
 	 * @param string $gid
 	 * @param string $displayName
-	 * @return \OCP\IGroup
+	 * @return \OCP\IGroup|null
 	 */
 	protected function getGroupObject($gid, $displayName = null) {
 		$backends = [];
@@ -210,11 +210,11 @@ class Manager extends PublicEmitter implements IGroupManager {
 
 	/**
 	 * @param string $gid
-	 * @return IGroup|bool|null
+	 * @return IGroup|null
 	 */
 	public function createGroup($gid) {
 		if ($gid === '' || $gid === null) {
-			return false;
+			return null;
 		} else if ($group = $this->get($gid)) {
 			return $group;
 		} else {

lib/private/Setup.php

@@ -50,6 +50,7 @@ use OC\Authentication\Token\DefaultTokenProvider;
 use OC\Log\Rotate;
 use OC\Preview\BackgroundCleanupJob;
 use OCP\Defaults;
+use OCP\IGroup;
 use OCP\IL10N;
 use OCP\ILogger;
 use OCP\IUser;
@@ -380,7 +381,9 @@ class Setup {
 			$config->setAppValue('core', 'vendor', $this->getVendor());
 
 			$group =\OC::$server->getGroupManager()->createGroup('admin');
-			$group->addUser($user);
+			if($group instanceof IGroup) {
+				$group->addUser($user);
+			}
 
 			// Install shipped apps and specified app bundles
 			Installer::installShippedApps();

lib/public/IGroupManager.php

@@ -75,7 +75,7 @@ interface IGroupManager {
 
 	/**
 	 * @param string $gid
-	 * @return \OCP\IGroup
+	 * @return \OCP\IGroup|null
 	 * @since 8.0.0
 	 */
 	public function get($gid);
@@ -89,7 +89,7 @@ interface IGroupManager {
 
 	/**
 	 * @param string $gid
-	 * @return \OCP\IGroup
+	 * @return \OCP\IGroup|null
 	 * @since 8.0.0
 	 */
 	public function createGroup($gid);