Merge pull request #11242 from annando/private-forums

Private forums are now working via AP

database.sql

@@ -1,6 +1,6 @@
 -- ------------------------------------------
 -- Friendica 2022.05-dev (Siberian Iris)
--- DB_UPDATE_VERSION 1451
+-- DB_UPDATE_VERSION 1452
 -- ------------------------------------------
 
 
@@ -1277,7 +1277,7 @@ CREATE TABLE IF NOT EXISTS `post-thread-user` (
 	`wall` boolean NOT NULL DEFAULT '0' COMMENT 'This item was posted to the wall of uid',
 	`mention` boolean NOT NULL DEFAULT '0' COMMENT '',
 	`pubmail` boolean NOT NULL DEFAULT '0' COMMENT '',
-	`forum_mode` tinyint unsigned NOT NULL DEFAULT 0 COMMENT '',
+	`forum_mode` tinyint unsigned NOT NULL DEFAULT 0 COMMENT 'Deprecated',
 	`contact-id` int unsigned NOT NULL DEFAULT 0 COMMENT 'contact.id',
 	`unseen` boolean NOT NULL DEFAULT '1' COMMENT 'post has not been seen',
 	`hidden` boolean NOT NULL DEFAULT '0' COMMENT 'Marker to hide the post from the user',
@@ -1612,7 +1612,6 @@ CREATE VIEW `post-user-view` AS SELECT
 	`post-user`.`deleted` AS `deleted`,
 	`post-user`.`origin` AS `origin`,
 	`post-thread-user`.`origin` AS `parent-origin`,
-	`post-thread-user`.`forum_mode` AS `forum_mode`,
 	`post-thread-user`.`mention` AS `mention`,
 	`post-user`.`global` AS `global`,
 	`post-user`.`network` AS `network`,
@@ -1773,7 +1772,6 @@ CREATE VIEW `post-thread-user-view` AS SELECT
 	`post-thread-user`.`unseen` AS `unseen`,
 	`post-user`.`deleted` AS `deleted`,
 	`post-thread-user`.`origin` AS `origin`,
-	`post-thread-user`.`forum_mode` AS `forum_mode`,
 	`post-thread-user`.`mention` AS `mention`,
 	`post-user`.`global` AS `global`,
 	`post-thread-user`.`network` AS `network`,

doc/database/db_post-thread-user.md

@@ -24,7 +24,7 @@ Fields
 | wall         | This item was posted to the wall of uid                                                                 | boolean            | NO   |     | 0                   |       |
 | mention      |                                                                                                         | boolean            | NO   |     | 0                   |       |
 | pubmail      |                                                                                                         | boolean            | NO   |     | 0                   |       |
-| forum_mode   |                                                                                                         | tinyint unsigned   | NO   |     | 0                   |       |
+| forum_mode   | Deprecated                                                                                              | tinyint unsigned   | NO   |     | 0                   |       |
 | contact-id   | contact.id                                                                                              | int unsigned       | NO   |     | 0                   |       |
 | unseen       | post has not been seen                                                                                  | boolean            | NO   |     | 1                   |       |
 | hidden       | Marker to hide the post from the user                                                                   | boolean            | NO   |     | 0                   |       |

mod/item.php

@@ -29,7 +29,6 @@
  */
 
 use Friendica\App;
-use Friendica\Content\Item as ItemHelper;
 use Friendica\Content\PageInfo;
 use Friendica\Content\Text\BBCode;
 use Friendica\Core\Hook;
@@ -40,11 +39,11 @@ use Friendica\Core\System;
 use Friendica\Core\Worker;
 use Friendica\Database\DBA;
 use Friendica\DI;
-use Friendica\Model\APContact;
 use Friendica\Model\Attach;
 use Friendica\Model\Contact;
 use Friendica\Model\Conversation;
 use Friendica\Model\FileTag;
+use Friendica\Model\Group;
 use Friendica\Model\Item;
 use Friendica\Model\ItemURI;
 use Friendica\Model\Notification;
@@ -404,7 +403,7 @@ function item_post(App $a) {
 			}
 			$inform .= 'cid:' . $contact['id'];
 
-			if (!$toplevel_item_id || empty($contact['cid']) || ($contact['contact-type'] != Contact::TYPE_COMMUNITY)) {
+			if ($toplevel_item_id || empty($contact['cid']) || ($contact['contact-type'] != Contact::TYPE_COMMUNITY)) {
 				continue;
 			}
 
@@ -437,26 +436,15 @@ function item_post(App $a) {
 			$postopts = '';
 		}
 
-		if (!$private_forum) {
-			$str_contact_allow = '';
-			$str_group_allow   = '';
 		$str_contact_deny  = '';
 		$str_group_deny    = '';
-		}
 
-		if ($private_forum || !APContact::getByURL($forum_contact['url'])) {
-			$str_group_allow = '';
-			$str_contact_deny = '';
-			$str_group_deny = '';
 		if ($private_forum) {
 			$str_contact_allow = '<' . $private_id . '>';
+			$str_group_allow   = '<' . Group::getIdForForum($forum_contact['id']) . '>';
 		} else {
 			$str_contact_allow = '';
-			}
+			$str_group_allow   = '';
-			$contact_id = $private_id;
-			$contact_record = $forum_contact;
-			$_REQUEST['origin'] = false;
-			$wall = 0;
 		}
 	}
 

src/Model/Contact.php

@@ -685,7 +685,7 @@ class Contact
 	 */
 	public static function updateSelfFromUserID($uid, $update_avatar = false)
 	{
-		$fields = ['id', 'name', 'nick', 'location', 'about', 'keywords', 'avatar', 'prvkey', 'pubkey',
+		$fields = ['id', 'name', 'nick', 'location', 'about', 'keywords', 'avatar', 'prvkey', 'pubkey', 'manually-approve',
 			'xmpp', 'matrix', 'contact-type', 'forum', 'prv', 'avatar-date', 'url', 'nurl', 'unsearchable',
 			'photo', 'thumb', 'micro', 'header', 'addr', 'request', 'notify', 'poll', 'confirm', 'poco', 'network'];
 		$self = DBA::selectFirst('contact', $fields, ['uid' => $uid, 'self' => true]);
@@ -757,6 +757,7 @@ class Contact
 		$fields['forum'] = $user['page-flags'] == User::PAGE_FLAGS_COMMUNITY;
 		$fields['prv'] = $user['page-flags'] == User::PAGE_FLAGS_PRVGROUP;
 		$fields['unsearchable'] = !$profile['net-publish'];
+		$fields['manually-approve'] = in_array($user['page-flags'], [User::PAGE_FLAGS_NORMAL, User::PAGE_FLAGS_PRVGROUP]);
 
 		$update = false;
 

src/Model/Group.php

@@ -41,7 +41,7 @@ class Group
 
 	public static function getByUserId($uid, $includesDeleted = false)
 	{
-		$conditions = ['uid' => $uid];
+		$conditions = ['uid' => $uid, 'cid' => null];
 
 		if (!$includesDeleted) {
 			$conditions['deleted'] = false;
@@ -408,7 +408,7 @@ class Group
 			]
 		];
 
-		$stmt = DBA::select('group', [], ['deleted' => 0, 'uid' => $uid], ['order' => ['name']]);
+		$stmt = DBA::select('group', [], ['deleted' => false, 'uid' => $uid, 'cid' => null], ['order' => ['name']]);
 		while ($group = DBA::fetch($stmt)) {
 			$display_groups[] = [
 				'name' => $group['name'],
@@ -465,7 +465,7 @@ class Group
 			$member_of = self::getIdsByContactId($cid);
 		}
 
-		$stmt = DBA::select('group', [], ['deleted' => 0, 'uid' => local_user()], ['order' => ['name']]);
+		$stmt = DBA::select('group', [], ['deleted' => false, 'uid' => local_user(), 'cid' => null], ['order' => ['name']]);
 		while ($group = DBA::fetch($stmt)) {
 			$selected = (($group_id == $group['id']) ? ' group-selected' : '');
 
@@ -522,19 +522,17 @@ class Group
 	}
 
 	/**
-	 * Fetch the followers of a given contact id and store them as group members
+	 * Fetch the group id for the given contact id
 	 *
 	 * @param integer $id Contact ID
+	 * @return integer Group IO
 	 */
-	public static function getMembersForForum(int $id) {
+	public static function getIdForForum(int $id)
-		$contact = Contact::getById($id, ['uid', 'url', 'name']);
+	{
-		if (empty($contact)) {
+		Logger::info('Get id for forum id', ['id' => $id]);
-			return;
+		$contact = Contact::getById($id, ['uid', 'name', 'contact-type', 'manually-approve']);
-		}
+		if (empty($contact) || ($contact['contact-type'] != Contact::TYPE_COMMUNITY) || !$contact['manually-approve']) {
-	
+			return 0;
-		$apcontact = APContact::getByURL($contact['url']);
-		if (empty($apcontact['followers'])) {
-			return;
 		}
 
 		$group = DBA::selectFirst('group', ['id'], ['uid' => $contact['uid'], 'cid' => $id]);
@@ -550,6 +548,33 @@ class Group
 			$gid = $group['id'];
 		}
 
+		return $gid;
+	}
+
+	/**
+	 * Fetch the followers of a given contact id and store them as group members
+	 *
+	 * @param integer $id Contact ID
+	 */
+	public static function getMembersForForum(int $id)
+	{
+		Logger::info('Update forum members', ['id' => $id]);
+
+		$contact = Contact::getById($id, ['uid', 'url']);
+		if (empty($contact)) {
+			return;
+		}
+
+		$apcontact = APContact::getByURL($contact['url']);
+		if (empty($apcontact['followers'])) {
+			return;
+		}
+
+		$gid = self::getIdForForum($id);
+		if (empty($gid)) {
+			return;
+		}
+
 		$group_members = DBA::selectToArray('group_member', ['contact-id'], ['gid' => $gid]);
 		if (!empty($group_members)) {
 			$current = array_unique(array_column($group_members, 'contact-id'));
@@ -557,7 +582,7 @@ class Group
 			$current = [];
 		}
 
-		foreach (ActivityPub::fetchItems($apcontact['followers']) as $follower) {
+		foreach (ActivityPub::fetchItems($apcontact['followers'], $contact['uid']) as $follower) {
 			$id = Contact::getIdForURL($follower);
 			if (!in_array($id, $current)) {
 				DBA::insert('group_member', ['gid' => $gid, 'contact-id' => $id]);
@@ -568,5 +593,6 @@ class Group
 		}
 
 		DBA::delete('group_member', ['gid' => $gid, 'contact-id' => $current]);
+		Logger::info('Updated forum members', ['id' => $id, 'count' => DBA::count('group_member', ['gid' => $gid])]);
 	}
 }

src/Model/Item.php

@@ -100,7 +100,7 @@ class Item
 			'inform', 'deleted', 'extid', 'post-type', 'post-reason', 'gravity',
 			'allow_cid', 'allow_gid', 'deny_cid', 'deny_gid',
 			'author-id', 'author-link', 'author-name', 'author-avatar', 'owner-id', 'owner-link', 'contact-uid',
-			'signed_text', 'network', 'wall', 'contact-id', 'plink', 'forum_mode', 'origin',
+			'signed_text', 'network', 'wall', 'contact-id', 'plink', 'origin',
 			'thr-parent-id', 'parent-uri-id', 'postopts', 'pubmail',
 			'event-created', 'event-edited', 'event-start', 'event-finish',
 			'event-summary', 'event-desc', 'event-location', 'event-type',
@@ -114,7 +114,7 @@ class Item
 			'postopts', 'plink', 'resource-id', 'event-id', 'inform',
 			'allow_cid', 'allow_gid', 'deny_cid', 'deny_gid', 'post-type', 'post-reason',
 			'private', 'pubmail', 'visible', 'starred',
-			'unseen', 'deleted', 'origin', 'forum_mode', 'mention', 'global', 'network',
+			'unseen', 'deleted', 'origin', 'mention', 'global', 'network',
 			'title', 'content-warning', 'body', 'location', 'coord', 'app',
 			'rendered-hash', 'rendered-html', 'object-type', 'object', 'target-type', 'target',
 			'author-id', 'author-link', 'author-name', 'author-avatar', 'author-network',
@@ -655,7 +655,7 @@ class Item
 		$fields = ['uid', 'uri', 'parent-uri', 'id', 'deleted',
 			'uri-id', 'parent-uri-id',
 			'allow_cid', 'allow_gid', 'deny_cid', 'deny_gid',
-			'wall', 'private', 'forum_mode', 'origin', 'author-id'];
+			'wall', 'private', 'origin', 'author-id'];
 		$condition = ['uri-id' => $item['thr-parent-id'], 'uid' => $item['uid']];
 		$params = ['order' => ['id' => false]];
 		$parent = Post::selectFirst($fields, $condition, $params);
@@ -818,6 +818,15 @@ class Item
 		$item['inform']        = trim($item['inform'] ?? '');
 		$item['file']          = trim($item['file'] ?? '');
 
+		// Communities aren't working with the Diaspora protoccol
+		if (($uid != 0) && ($item['network'] == Protocol::DIASPORA)) {
+			$user = User::getById($uid, ['account-type']);
+		 	if ($user['account-type'] == Contact::TYPE_COMMUNITY) {
+				Logger::info('Community posts are not supported via Diaspora');
+				return 0;
+			}
+		}
+
 		// Items cannot be stored before they happen ...
 		if ($item['created'] > DateTimeFormat::utcNow()) {
 			$item['created'] = DateTimeFormat::utcNow();
@@ -881,10 +890,15 @@ class Item
 			$item['parent-uri']    = $toplevel_parent['uri'];
 			$item['parent-uri-id'] = $toplevel_parent['uri-id'];
 			$item['deleted']       = $toplevel_parent['deleted'];
+
+			// Reshares have to keep their permissions to allow forums to work
+			if (!$item['origin'] || ($item['verb'] != Activity::ANNOUNCE)) {
 				$item['allow_cid']     = $toplevel_parent['allow_cid'];
 				$item['allow_gid']     = $toplevel_parent['allow_gid'];
 				$item['deny_cid']      = $toplevel_parent['deny_cid'];
 				$item['deny_gid']      = $toplevel_parent['deny_gid'];
+			}
+
 			$parent_origin         = $toplevel_parent['origin'];
 
 			// Don't federate received participation messages
@@ -905,15 +919,6 @@ class Item
 				$item['private'] = $toplevel_parent['private'];
 			}
 
-			/*
-			 * Edge case. We host a public forum that was originally posted to privately.
-			 * The original author commented, but as this is a comment, the permissions
-			 * weren't fixed up so it will still show the comment as private unless we fix it here.
-			 */
-			if ((intval($toplevel_parent['forum_mode']) == 1) && ($toplevel_parent['private'] != self::PUBLIC)) {
-				$item['private'] = self::PUBLIC;
-			}
-
 			// If its a post that originated here then tag the thread as "mention"
 			if ($item['origin'] && $item['uid']) {
 				DBA::update('post-thread-user', ['mention' => true], ['uri-id' => $item['parent-uri-id'], 'uid' => $item['uid']]);
@@ -1406,9 +1411,15 @@ class Item
 		}
 
 		if ((($item['gravity'] == GRAVITY_COMMENT) || $is_reshare) && !Post::exists(['uri-id' => $item['thr-parent-id'], 'uid' => $uid])) {
-			// Only do an auto complete with the source uid "0" to prevent privavy problems
+			// Fetch the origin user for the post
+			$origin_uid = self::GetOriginUidForUriId($item['thr-parent-id'], $uid);
+			if (is_null($origin_uid)) {
+				Logger::info('Origin item was not found', ['uid' => $uid, 'uri-id' => $item['thr-parent-id']]);
+				return 0;
+			}
+
 			$causer = $item['causer-id'] ?: $item['author-id'];
-			$result = self::storeForUserByUriId($item['thr-parent-id'], $uid, ['causer-id' => $causer, 'post-reason' => self::PR_FETCHED]);
+			$result = self::storeForUserByUriId($item['thr-parent-id'], $uid, ['causer-id' => $causer, 'post-reason' => self::PR_FETCHED], $origin_uid);
 			Logger::info('Fetched thread parent', ['uri-id' => $item['thr-parent-id'], 'uid' => $uid, 'causer' => $causer, 'result' => $result]);
 		}
 
@@ -1417,6 +1428,46 @@ class Item
 		return $stored;
 	}
 
+	/**
+	 * Returns the origin uid of a post if the given user is allowed to see it.
+	 *
+	 * @param int $uriid
+	 * @param int $uid
+	 * @return int
+	 */
+	private static function GetOriginUidForUriId(int $uriid, int $uid)
+	{
+		if (Post::exists(['uri-id' => $uriid, 'uid' => $uid])) {
+			return $uid;
+		}
+
+		$post = Post::selectFirst(['uid', 'allow_cid', 'allow_gid', 'deny_cid', 'deny_gid', 'private'], ['uri-id' => $uriid, 'origin' => true]);
+		if (empty($post)) {
+			if (Post::exists(['uri-id' => $uriid, 'uid' => 0])) {
+				return 0;
+			} else {
+				return null;
+			}
+		}
+
+		if (in_array($post['private'], [Item::PUBLIC, Item::UNLISTED])) {
+			return $post['uid'];
+		}
+
+		$pcid = Contact::getPublicIdByUserId($uid);
+		if (empty($pcid)) {
+			return null;
+		}
+
+		foreach (Item::enumeratePermissions($post, true) as $receiver) {
+			if ($receiver == $pcid) {
+				return $post['uid'];
+			}
+		}
+
+		return null;
+	}
+
 	/**
 	 * Store a public item array for the given users
 	 *
@@ -1443,6 +1494,7 @@ class Item
 			return 0;
 		}
 
+		// Data from the "post-user" table
 		unset($item['id']);
 		unset($item['mention']);
 		unset($item['starred']);
@@ -1451,11 +1503,14 @@ class Item
 		unset($item['pinned']);
 		unset($item['ignored']);
 		unset($item['pubmail']);
-		unset($item['forum_mode']);
-
 		unset($item['event-id']);
 		unset($item['hidden']);
 		unset($item['notification-type']);
+		unset($item['post-reason']);
+
+		// Data from the "post-delivery-data" table
+		unset($item['postopts']);
+		unset($item['inform']);
 
 		$item['uid'] = $uid;
 		$item['origin'] = 0;
@@ -1928,41 +1983,18 @@ class Item
 
 		Logger::info('Community post will be distributed', ['uri' => $item['uri'], 'uid' => $uid, 'id' => $item_id, 'uri-id' => $item['uri-id'], 'guid' => $item['guid']]);
 
-		self::performActivity($item['id'], 'announce', $uid);
+		if ($owner['page-flags'] == User::PAGE_FLAGS_PRVGROUP) {
+			Group::getMembersForForum($owner['id']);
 
-		/**
+			$allow_cid = '<' . $owner['id'] . '>';
-		 * All the following lines are only needed for private forums and compatibility to older systems without AP support.
+			$allow_gid = '<' . Group::getIdForForum($owner['id']) . '>';
-		 * A possible way would be that the followers list of a forum would always be readable by all followers.
+			$deny_cid  = '';
-		 * So this would mean that the comment distribution could be done exactly for the intended audience.
+			$deny_gid  = '';
-		 * Or possibly we could store the receivers that had been in the "announce" message above and use this.
+			self::performActivity($item['id'], 'announce', $uid, $allow_cid, $allow_gid, $deny_cid, $deny_gid);
-		 */
-
-		// also reset all the privacy bits to the forum default permissions
-		if ($owner['allow_cid'] || $owner['allow_gid'] || $owner['deny_cid'] || $owner['deny_gid']) {
-			$private = self::PRIVATE;
-		} elseif (DI::pConfig()->get($owner['uid'], 'system', 'unlisted')) {
-			$private = self::UNLISTED;
 		} else {
-			$private = self::PUBLIC;
+			self::performActivity($item['id'], 'announce', $uid);
 		}
 
-		$permissionSet = DI::permissionSet()->selectOrCreate(
-			DI::permissionSetFactory()->createFromString(
-				$owner['uid'],
-				$owner['allow_cid'],
-				$owner['allow_gid'],
-				$owner['deny_cid'],
-				$owner['deny_gid']
-			));
-
-		$forum_mode = ($owner['page-flags'] == User::PAGE_FLAGS_PRVGROUP) ? 2 : 1;
-
-		$fields = ['wall' => true, 'origin' => true, 'forum_mode' => $forum_mode, 'contact-id' => $owner['id'],
-			'owner-id' => Contact::getPublicIdByUserId($uid), 'private' => $private, 'psid' => $permissionSet->id];
-		self::update($fields, ['id' => $item['id']]);
-
-		Worker::add(['priority' => PRIORITY_HIGH, 'dont_fork' => true], 'Notifier', Delivery::POST, (int)$item['uri-id'], (int)$item['uid']);
-
 		Logger::info('Community post had been distributed', ['uri' => $item['uri'], 'uid' => $uid, 'id' => $item_id, 'uri-id' => $item['uri-id'], 'guid' => $item['guid']]);
 		return false;
 	}
@@ -2331,6 +2363,11 @@ class Item
 	 *            like, unlike, dislike, undislike, attendyes, unattendyes,
 	 *            attendno, unattendno, attendmaybe, unattendmaybe,
 	 *            announce, unannouce
+	 * @param int    $uid
+	 * @param string $allow_cid
+	 * @param string $allow_gid
+	 * @param string $deny_cid
+	 * @param string $deny_gid
 	 * @return bool
 	 * @throws \Friendica\Network\HTTPException\InternalServerErrorException
 	 * @throws \ImagickException
@@ -2338,7 +2375,7 @@ class Item
 	 *            array $arr
 	 *            'post_id' => ID of posted item
 	 */
-	public static function performActivity(int $item_id, string $verb, int $uid)
+	public static function performActivity(int $item_id, string $verb, int $uid, string $allow_cid = null, string $allow_gid = null, string $deny_cid = null, string $deny_gid = null)
 	{
 		if (empty($uid)) {
 			return false;
@@ -2499,10 +2536,10 @@ class Item
 			'body'          => $activity,
 			'verb'          => $activity,
 			'object-type'   => $objtype,
-			'allow_cid'     => $item['allow_cid'],
+			'allow_cid'     => $allow_cid ?? $item['allow_cid'],
-			'allow_gid'     => $item['allow_gid'],
+			'allow_gid'     => $allow_gid ?? $item['allow_gid'],
-			'deny_cid'      => $item['deny_cid'],
+			'deny_cid'      => $deny_cid ?? $item['deny_cid'],
-			'deny_gid'      => $item['deny_gid'],
+			'deny_gid'      => $deny_gid ?? $item['deny_gid'],
 			'visible'       => 1,
 			'unseen'        => 1,
 		];

src/Model/Post/UserNotification.php

@@ -33,6 +33,7 @@ use Friendica\Model\Contact;
 use Friendica\Model\Post;
 use Friendica\Model\Subscription;
 use Friendica\Model\Tag;
+use Friendica\Model\User;
 use Friendica\Navigation\Notifications;
 use Friendica\Network\HTTPException;
 use Friendica\Protocol\Activity;
@@ -176,6 +177,11 @@ class UserNotification
 			return;
 		}
 
+		$user = User::getById($uid, ['account-type']);
+		if (in_array($user['account-type'], [User::ACCOUNT_TYPE_COMMUNITY, User::ACCOUNT_TYPE_RELAY])) {
+			return;
+		}
+
 		$notification_type = self::TYPE_NONE;
 
 		if (self::checkShared($item, $uid)) {

src/Module/Api/Twitter/Lists/Ownership.php

@@ -56,7 +56,7 @@ class Ownership extends BaseApi
 		BaseApi::checkAllowedScope(BaseApi::SCOPE_READ);
 		$uid = BaseApi::getCurrentUserID();
 
-		$groups = $this->dba->select('group', [], ['deleted' => false, 'uid' => $uid]);
+		$groups = $this->dba->select('group', [], ['deleted' => false, 'uid' => $uid, 'cid' => null]);
 
 		// loop through all groups
 		$lists = [];

src/Module/Diaspora/Receive.php

@@ -93,6 +93,12 @@ class Receive extends BaseModule
 
 		$importer = User::getByGuid($this->parameters['guid']);
 
+		if ($importer['account-type'] == User::ACCOUNT_TYPE_COMMUNITY) {
+			// Communities aren't working with the Diaspora protoccol
+			// We throw an "accepted" here, so that the sender doesn't repeat the delivery
+			throw new HTTPException\AcceptedException();
+		}
+
 		$msg = $this->decodePost(false, $importer['prvkey'] ?? '');
 
 		$this->logger->info('Diaspora: Dispatching.');

src/Protocol/ActivityPub/Receiver.php

@@ -263,7 +263,9 @@ class Receiver
 	{
 		$id = JsonLD::fetchElement($activity, '@id');
 		if (!empty($id) && !$trust_source) {
-			$fetched_activity = ActivityPub::fetchContent($id, $uid ?? 0);
+			$fetch_uid = $uid ?: self::getBestUserForActivity($activity);
+
+			$fetched_activity = ActivityPub::fetchContent($id, $fetch_uid);
 			if (!empty($fetched_activity)) {
 				$object = JsonLD::compact($fetched_activity);
 				$fetched_id = JsonLD::fetchElement($object, '@id');
@@ -302,12 +304,12 @@ class Receiver
 			if (empty($activity['thread-completion']) && (empty($reception_types[$uid]) || in_array($reception_types[$uid], [self::TARGET_UNKNOWN, self::TARGET_FOLLOWER, self::TARGET_ANSWER, self::TARGET_GLOBAL]))) {
 				$reception_types[$uid] = self::TARGET_BCC;
 			}
-		} else {
-			// We possibly need some user to fetch private content,
-			// so we fetch the first out ot the list.
-			$uid = self::getFirstUserFromReceivers($receivers);
 		}
 
+		// We possibly need some user to fetch private content,
+		// so we fetch one out of the receivers if no uid is provided.
+		$fetch_uid = $uid ?: self::getBestUserForActivity($activity);
+
 		$object_id = JsonLD::fetchElement($activity, 'as:object', '@id');
 		if (empty($object_id)) {
 			Logger::info('No object found');
@@ -319,11 +321,11 @@ class Receiver
 			return [];
 		}
 
-		$object_type = self::fetchObjectType($activity, $object_id, $uid);
+		$object_type = self::fetchObjectType($activity, $object_id, $fetch_uid);
 
 		// Fetch the activity on Lemmy "Announce" messages (announces of activities)
 		if (($type == 'as:Announce') && in_array($object_type, array_merge(self::ACTIVITY_TYPES, ['as:Delete', 'as:Undo', 'as:Update']))) {
-			$data = ActivityPub::fetchContent($object_id, $uid);
+			$data = ActivityPub::fetchContent($object_id, $fetch_uid);
 			if (!empty($data)) {
 				$type = $object_type;
 				$activity = JsonLD::compact($data);
@@ -331,7 +333,7 @@ class Receiver
 				// Some variables need to be refetched since the activity changed
 				$actor = JsonLD::fetchElement($activity, 'as:actor', '@id');
 				$object_id = JsonLD::fetchElement($activity, 'as:object', '@id');
-				$object_type = self::fetchObjectType($activity, $object_id, $uid);
+				$object_type = self::fetchObjectType($activity, $object_id, $fetch_uid);
 			}
 		}
 
@@ -348,7 +350,7 @@ class Receiver
 		// Fetch the content only on activities where this matters
 		// We can receive "#emojiReaction" when fetching content from Hubzilla systems
 			// Always fetch on "Announce"
-			$object_data = self::fetchObject($object_id, $activity['as:object'], $trust_source && ($type != 'as:Announce'), $uid);
+			$object_data = self::fetchObject($object_id, $activity['as:object'], $trust_source && ($type != 'as:Announce'), $fetch_uid);
 			if (empty($object_data)) {
 				Logger::info("Object data couldn't be processed");
 				return [];
@@ -396,7 +398,7 @@ class Receiver
 
 			// An Undo is done on the object of an object, so we need that type as well
 			if (($type == 'as:Undo') && !empty($object_data['object_object'])) {
-				$object_data['object_object_type'] = self::fetchObjectType([], $object_data['object_object'], $uid);
+				$object_data['object_object_type'] = self::fetchObjectType([], $object_data['object_object'], $fetch_uid);
 			}
 		}
 
@@ -643,6 +645,31 @@ class Receiver
 		}
 	}
 
+	/**
+	 * Fetch a user id from an activity array
+	 *
+	 * @param array  $activity
+	 * @param string $actor
+	 *
+	 * @return int   user id
+	 */
+	public static function getBestUserForActivity(array $activity)
+	{
+		$uid = 0;
+		$actor = JsonLD::fetchElement($activity, 'as:actor', '@id') ?? '';
+
+		$receivers = self::getReceivers($activity, $actor);
+		foreach ($receivers as $receiver) {
+			if ($receiver['type'] == self::TARGET_GLOBAL) {
+				return 0;
+			}
+			if (empty($uid) || ($receiver['type'] == self::TARGET_TO)) {
+				$uid = $receiver['uid'];
+			}
+		}
+		return $uid;
+	}
+
 	/**
 	 * Fetch the receiver list from an activity array
 	 *

src/Protocol/ActivityPub/Transmitter.php

@@ -184,7 +184,7 @@ class Transmitter
 
 		// Allow fetching the contact list when the requester is part of the list.
 		if (($owner['page-flags'] == User::PAGE_FLAGS_PRVGROUP) && !empty($requester)) {
-			$show_contacts = DBA::exists('contact', ['nurl' => Strings::normaliseLink($requester), 'rel' => $rel]);
+			$show_contacts = DBA::exists('contact', ['nurl' => Strings::normaliseLink($requester), 'uid' => $owner['uid'], 'blocked' => false]);
 		}
 
 		if (!$show_contacts) {
@@ -600,12 +600,20 @@ class Transmitter
 						continue;
 					}
 
-					if (!empty($profile = APContact::getByURL($contact['url'], false))) {
+					$profile = APContact::getByURL($term['url'], false);
+					if (!empty($profile)) {
+						if ($term['type'] == Tag::EXCLUSIVE_MENTION) {
+							$exclusive = true;
+							if (!empty($profile['followers']) && ($profile['type'] == 'Group')) {
+								$data['cc'][] = $profile['followers'];
+							}
+						}
 						$data['to'][] = $profile['url'];
 					}
 				}
 			}
 
+			if (!$exclusive) {
 				foreach ($receiver_list as $receiver) {
 					$contact = DBA::selectFirst('contact', ['url', 'hidden', 'network', 'protocol', 'gsid'], ['id' => $receiver, 'network' => Protocol::FEDERATED]);
 					if (!DBA::isResult($contact) || !self::isAPContact($contact, $networks)) {
@@ -621,6 +629,7 @@ class Transmitter
 					}
 				}
 			}
+		}
 
 		if (!empty($item['parent'])) {
 			$parents = Post::select(['id', 'author-link', 'owner-link', 'gravity', 'uri'], ['parent' => $item['parent']]);
@@ -1079,20 +1088,6 @@ class Transmitter
 			return false;
 		}
 
-		// In case of a forum post ensure to return the original post if author and forum are on the same machine
-		if (($item['gravity'] == GRAVITY_PARENT) && !empty($item['forum_mode'])) {
-			$author = Contact::getById($item['author-id'], ['nurl']);
-			if (!empty($author['nurl'])) {
-				$self = Contact::selectFirst(['uid'], ['nurl' => $author['nurl'], 'self' => true]);
-				if (!empty($self['uid'])) {
-					$forum_item = Post::selectFirst(Item::DELIVER_FIELDLIST, ['uri-id' => $item['uri-id'], 'uid' => $self['uid']]);
-					if (DBA::isResult($forum_item)) {
-						$item = $forum_item;
-					}
-				}
-			}
-		}
-
 		if (empty($item['uri-id'])) {
 			Logger::warning('Item without uri-id', ['item' => $item]);
 			return false;

src/Protocol/DFRN.php

@@ -1557,22 +1557,11 @@ class DFRN
 
 			// was the top-level post for this action written by somebody on this site?
 			// Specifically, the recipient?
-			$parent = Post::selectFirst(['forum_mode', 'wall'],
+			$parent = Post::selectFirst(['wall'],
 				["`uri` = ? AND `uid` = ?" . $sql_extra, $item["thr-parent"], $importer["importer_uid"]]);
 
 			$is_a_remote_action = DBA::isResult($parent);
 
-			/*
-			 * Does this have the characteristics of a community or private group action?
-			 * If it's an action to a wall post on a community/prvgroup page it's a
-			 * valid community action. Also forum_mode makes it valid for sure.
-			 * If neither, it's not.
-			 */
-			if ($is_a_remote_action && $community && (!$parent["forum_mode"]) && (!$parent["wall"])) {
-				$is_a_remote_action = false;
-				Logger::notice("not a community action");
-			}
-
 			if ($is_a_remote_action) {
 				return DFRN::REPLY_RC;
 			} else {

src/Protocol/Diaspora.php

@@ -858,10 +858,6 @@ class Diaspora
 		} elseif (($contact["rel"] == Contact::SHARING) || ($contact["rel"] == Contact::FRIEND)) {
 			// Yes, then it is fine.
 			return true;
-			// Is it a post to a community?
-		} elseif (($contact["rel"] == Contact::FOLLOWER) && ($importer['account-type'] == User::ACCOUNT_TYPE_COMMUNITY)) {
-			// That's good
-			return true;
 			// Is the message a global user or a comment?
 		} elseif (($importer["uid"] == 0) || $is_comment) {
 			// Messages for the global users and comments are always accepted
@@ -3473,9 +3469,8 @@ class Diaspora
 
 	private static function prependParentAuthorMention($body, $profile_url)
 	{
-		$profile = Contact::getByURL($profile_url, false, ['addr', 'name', 'contact-type']);
+		$profile = Contact::getByURL($profile_url, false, ['addr', 'name']);
 		if (!empty($profile['addr'])
-			&& $profile['contact-type'] != Contact::TYPE_COMMUNITY
 			&& !strstr($body, $profile['addr'])
 			&& !strstr($body, $profile_url)
 		) {

src/Worker/Delivery.php

@@ -46,7 +46,6 @@ class Delivery
 	const DELETION      = 'drop';
 	const POST          = 'wall-new';
 	const POKE          = 'poke';
-	const UPLINK        = 'uplink';
 	const REMOVAL       = 'removeme';
 	const PROFILEUPDATE = 'profileupdate';
 

src/Worker/Notifier.php

@@ -153,7 +153,7 @@ class Notifier
 		}
 
 		// Should the post be transmitted to Diaspora?
-		$diaspora_delivery = true;
+		$diaspora_delivery = ($owner['account-type'] != User::ACCOUNT_TYPE_COMMUNITY);
 
 		// If this is a public conversation, notify the feed hub
 		$public_message = true;
@@ -223,10 +223,6 @@ class Notifier
 				$relay_to_owner = true;
 			}
 
-			if (($cmd === Delivery::UPLINK) && (intval($parent['forum_mode']) == 1) && !$top_level) {
-				$relay_to_owner = true;
-			}
-
 			// until the 'origin' flag has been in use for several months
 			// we will just use it as a fallback test
 			// later we will be able to use it as the primary test of whether or not to relay.
@@ -333,15 +329,6 @@ class Notifier
 				$deny_people  = $aclFormatter->expand($parent['deny_cid']);
 				$deny_groups  = Group::expand($uid, $aclFormatter->expand($parent['deny_gid']));
 
-				// if our parent is a public forum (forum_mode == 1), uplink to the origional author causing
-				// a delivery fork. private groups (forum_mode == 2) do not uplink
-				/// @todo Possibly we should not uplink when the author is the forum itself?
-
-				if ((intval($parent['forum_mode']) == 1) && !$top_level && ($cmd !== Delivery::UPLINK)
-					&& ($target_item['verb'] != Activity::ANNOUNCE)) {
-					Worker::add($a->getQueueValue('priority'), 'Notifier', Delivery::UPLINK, $post_uriid, $sender_uid);
-				}
-
 				foreach ($items as $item) {
 					$recipients[] = $item['contact-id'];
 					// pull out additional tagged people to notify (if public message)
@@ -813,15 +800,4 @@ class Notifier
 
 		return ['count' => $delivery_queue_count, 'contacts' => $contacts];
 	}
-
-	/**
-	 * Check if the delivered item is a forum post
-	 *
-	 * @param array $item
-	 * @return boolean
-	 */
-	public static function isForumPost(array $item)
-	{
-		return ($item['gravity'] == GRAVITY_PARENT) && !empty($item['forum_mode']);
-	}
 }

static/dbstructure.config.php

@@ -55,7 +55,7 @@
 use Friendica\Database\DBA;
 
 if (!defined('DB_UPDATE_VERSION')) {
-	define('DB_UPDATE_VERSION', 1451);
+	define('DB_UPDATE_VERSION', 1452);
 }
 
 return [
@@ -1301,7 +1301,7 @@ return [
 			"wall" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "This item was posted to the wall of uid"],
 			"mention" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
 			"pubmail" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => ""],
-			"forum_mode" => ["type" => "tinyint unsigned", "not null" => "1", "default" => "0", "comment" => ""],
+			"forum_mode" => ["type" => "tinyint unsigned", "not null" => "1", "default" => "0", "comment" => "Deprecated"],
 			"contact-id" => ["type" => "int unsigned", "not null" => "1", "default" => "0", "foreign" => ["contact" => "id"], "comment" => "contact.id"],
 			"unseen" => ["type" => "boolean", "not null" => "1", "default" => "1", "comment" => "post has not been seen"],
 			"hidden" => ["type" => "boolean", "not null" => "1", "default" => "0", "comment" => "Marker to hide the post from the user"],

static/dbview.config.php

@@ -91,7 +91,6 @@
 			"deleted" => ["post-user", "deleted"],
 			"origin" => ["post-user", "origin"],
 			"parent-origin" => ["post-thread-user", "origin"],
-			"forum_mode" => ["post-thread-user", "forum_mode"],
 			"mention" => ["post-thread-user", "mention"],
 			"global" => ["post-user", "global"],
 			"network" => ["post-user", "network"],
@@ -250,7 +249,6 @@
 			"unseen" => ["post-thread-user", "unseen"],
 			"deleted" => ["post-user", "deleted"],
 			"origin" => ["post-thread-user", "origin"],
-			"forum_mode" => ["post-thread-user", "forum_mode"],
 			"mention" => ["post-thread-user", "mention"],
 			"global" => ["post-user", "global"],
 			"network" => ["post-thread-user", "network"],