X-Git-Url: https://git.mxchange.org/?a=blobdiff_plain;f=src%2FModel%2FItem.php;h=d040c876de6df1ab4a1ee614102173943bfbc66a;hb=72a3ab6382551811f22391b7e82e7398628b235b;hp=8c2f2e205ce865957a487bdc35f204b98cb31317;hpb=3d8e82d95d9cc76b45a8db301b22c4111f335e1c;p=friendica.git

diff --git a/src/Model/Item.php b/src/Model/Item.php
index 8c2f2e205c..d040c876de 100644
--- a/src/Model/Item.php
+++ b/src/Model/Item.php
@@ -74,6 +74,11 @@ class Item
 	const PR_RELAY = 74;
 	const PR_FETCHED = 75;
 
+	// system.accept_only_sharer setting values
+	const COMPLETION_NONE    = 1;
+	const COMPLETION_COMMENT = 0;
+	const COMPLETION_LIKE    = 2;
+
 	// Field list that is used to display the items
 	const DISPLAY_FIELDLIST = [
 		'uid', 'id', 'parent', 'guid', 'network', 'gravity',
@@ -100,7 +105,7 @@ 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 +119,7 @@ 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 +660,7 @@ 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 +823,15 @@ 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 +895,15 @@ class Item
 			$item['parent-uri']    = $toplevel_parent['uri'];
 			$item['parent-uri-id'] = $toplevel_parent['uri-id'];
 			$item['deleted']       = $toplevel_parent['deleted'];
-			$item['allow_cid']     = $toplevel_parent['allow_cid'];
-			$item['allow_gid']     = $toplevel_parent['allow_gid'];
-			$item['deny_cid']      = $toplevel_parent['deny_cid'];
-			$item['deny_gid']      = $toplevel_parent['deny_gid'];
+
+			// Reshares have to keep their permissions to allow forums to work
+			if (!$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 +924,6 @@ 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' => $item['uid']]);
@@ -1066,6 +1076,13 @@ class Item
 			unset($item['causer-id']);
 		}
 
+		if (in_array($item['network'], [Protocol::ACTIVITYPUB, Protocol::DFRN])) {
+			$content_warning = BBCode::getAbstract($item['body'], Protocol::ACTIVITYPUB);
+			if (!empty($content_warning) && empty($item['content-warning'])) {
+				$item['content-warning'] = $content_warning;
+			}
+		}
+
 		Post::insert($item['uri-id'], $item);
 
 		if ($item['gravity'] == GRAVITY_PARENT) {
@@ -1226,8 +1243,11 @@ class Item
 			return;
 		}
 
+		$self_contact = Contact::selectFirst(['id'], ['uid' => $item['uid'], 'self' => true]);
+		$self = !empty($self_contact) ? $self_contact['id'] : 0;
+
 		$cid = Contact::getIdForURL($author['url'], $item['uid']);
-		if (empty($cid) || !Contact::isSharing($cid, $item['uid'])) {
+		if (empty($cid) || (!Contact::isSharing($cid, $item['uid']) && ($cid != $self))) {
 			Logger::info('The resharer is not a following contact: quit', ['resharer' => $author['url'], 'uid' => $item['uid'], 'cid' => $cid]);
 			return;
 		}
@@ -1398,7 +1418,7 @@ class Item
 		$is_reshare = ($item['gravity'] == GRAVITY_ACTIVITY) && ($item['verb'] == Activity::ANNOUNCE);
 
 		if ((($item['gravity'] == GRAVITY_PARENT) || $is_reshare) &&
-			DI::pConfig()->get($uid, 'system', 'accept_only_sharer') &&
+			DI::pConfig()->get($uid, 'system', 'accept_only_sharer') == self::COMPLETION_NONE &&
 			!Contact::isSharingByURL($item['author-link'], $uid) &&
 			!Contact::isSharingByURL($item['owner-link'], $uid)) {
 			Logger::info('Contact is not a follower, thread will not be stored', ['author' => $item['author-link'], 'uid' => $uid]);
@@ -1406,9 +1426,15 @@ 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 +1443,56 @@ 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 (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;
+		}
+
+		if (Post::exists(['uri-id' => $uriid, 'uid' => 0])) {
+			return 0;
+		}
+
+		// When the post belongs to a a forum then all forum users are allowed to access it
+		foreach (Tag::getByURIId($uriid, [Tag::MENTION, Tag::EXCLUSIVE_MENTION]) as $tag) {
+			if (DBA::exists('contact', ['uid' => $uid, 'nurl' => Strings::normaliseLink($tag['url']), 'contact-type' => Contact::TYPE_COMMUNITY])) {
+				$target_uid = User::getIdForURL($tag['url']);
+				if (!empty($target_uid)) {
+					return $target_uid;
+				}
+			}
+		}
+
+		return null;
+	}
+
 	/**
 	 * Store a public item array for the given users
 	 *
@@ -1428,10 +1504,22 @@ class Item
 	private static function storeForUser(array $item, int $uid)
 	{
 		if (Post::exists(['uri-id' => $item['uri-id'], 'uid' => $uid])) {
+			if (!empty($item['event-id'])) {
+				$post = Post::selectFirst(['event-id'], ['uri-id' => $item['uri-id'], 'uid' => $uid]);
+				if (!empty($post['event-id'])) {
+					$event = DBA::selectFirst('event', ['edited', 'start', 'finish', 'summary', 'desc', 'location', 'nofinish', 'adjust'], ['id' => $item['event-id']]);
+					if (!empty($event)) {
+						// We aren't using "Event::store" here, since we don't want to trigger any further action
+						$ret = DBA::update('event', $event, ['id' => $post['event-id']]);
+						Logger::info('Event updated', ['uid' => $uid, 'source-event' => $item['event-id'], 'target-event' => $post['event-id'], 'ret' => $ret]);
+					}
+				}
+			}
 			Logger::info('Item already exists', ['uri-id' => $item['uri-id'], 'uid' => $uid]);
 			return 0;
 		}
 
+		// Data from the "post-user" table
 		unset($item['id']);
 		unset($item['mention']);
 		unset($item['starred']);
@@ -1440,11 +1528,14 @@ class Item
 		unset($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;
@@ -1682,7 +1773,10 @@ class Item
 	}
 
 	/**
-	 * Creates an unique guid out of a given uri
+	 * Creates an unique guid out of a given uri.
+	 * This function is used for messages outside the fediverse (Connector posts, feeds, Mails, ...)
+	 * Posts that are created on this system are using System::createUUID.
+	 * Received ActivityPub posts are using Processor::getGUIDByURL.
 	 *
 	 * @param string $uri uri of an item entry
 	 * @param string $host hostname for the GUID prefix
@@ -1694,19 +1788,14 @@ class Item
 		// We have to avoid that different routines could accidentally create the same value
 		$parsed = parse_url($uri);
 
-		// We use a hash of the hostname as prefix for the guid
-		$guid_prefix = hash("crc32", $host);
-
 		// Remove the scheme to make sure that "https" and "http" doesn't make a difference
 		unset($parsed["scheme"]);
 
 		// Glue it together to be able to make a hash from it
 		$host_id = implode("/", $parsed);
 
-		// We could use any hash algorithm since it isn't a security issue
-		$host_hash = hash("ripemd128", $host_id);
-
-		return $guid_prefix.$host_hash;
+		// Use a mixture of several hashes to provide some GUID like experience
+		return hash("crc32", $host) . '-'. hash('joaat', $host_id) . '-'. hash('fnv164', $host_id);
 	}
 
 	/**
@@ -1862,117 +1951,69 @@ class Item
 	{
 		$mention = false;
 
-		$user = DBA::selectFirst('user', [], ['uid' => $uid]);
-		if (!DBA::isResult($user)) {
+		$owner = User::getOwnerDataById($uid);
+		if (!DBA::isResult($owner)) {
+			Logger::warning('User not found, quitting here.', ['uid' => $uid]);
 			return false;
 		}
 
-		$community_page = (($user['page-flags'] == User::PAGE_FLAGS_COMMUNITY) ? true : false);
-		$prvgroup = (($user['page-flags'] == User::PAGE_FLAGS_PRVGROUP) ? true : false);
-
-		$item = Post::selectFirst(self::ITEM_FIELDLIST, ['id' => $item_id]);
-		if (!DBA::isResult($item)) {
+		if ($owner['contact-type'] != User::ACCOUNT_TYPE_COMMUNITY) {
+			Logger::debug('Owner is no community, quitting here.', ['uid' => $uid, 'id' => $item_id]);
 			return false;
 		}
 
-		$link = Strings::normaliseLink(DI::baseUrl() . '/profile/' . $user['nickname']);
-
-		/*
-		 * Diaspora uses their own hardwired link URL in @-tags
-		 * instead of the one we supply with webfinger
-		 */
-		$dlink = Strings::normaliseLink(DI::baseUrl() . '/u/' . $user['nickname']);
-
-		$cnt = preg_match_all('/[\@\!]\[url\=(.*?)\](.*?)\[\/url\]/ism', $item['body'], $matches, PREG_SET_ORDER);
-		if ($cnt) {
-			foreach ($matches as $mtch) {
-				if (Strings::compareLink($link, $mtch[1]) || Strings::compareLink($dlink, $mtch[1])) {
-					$mention = true;
-					Logger::notice('mention found', ['mention' => $mtch[2]]);
-				}
-			}
+		$item = Post::selectFirst(self::ITEM_FIELDLIST, ['id' => $item_id, 'gravity' => [GRAVITY_PARENT, GRAVITY_COMMENT], 'origin' => false]);
+		if (!DBA::isResult($item)) {
+			Logger::debug('Post is an activity or origin or not found at all, quitting here.', ['id' => $item_id]);
+			return false;
 		}
 
-		if (!$mention) {
+		if ($item['gravity'] == GRAVITY_PARENT) {
 			$tags = Tag::getByURIId($item['uri-id'], [Tag::MENTION, Tag::EXCLUSIVE_MENTION]);
 			foreach ($tags as $tag) {
-				if (Strings::compareLink($link, $tag['url']) || Strings::compareLink($dlink, $tag['url'])) {
+				if (Strings::compareLink($owner['url'], $tag['url'])) {
 					$mention = true;
-					DI::logger()->info('mention found in tag.', ['url' => $tag['url']]);
+					Logger::info('Mention found in tag.', ['url' => $tag['url'], 'uri' => $item['uri'], 'uid' => $uid, 'id' => $item_id, 'uri-id' => $item['uri-id'], 'guid' => $item['guid']]);
 				}
 			}
-		}
 
-		if (!$mention) {
-			if (($community_page || $prvgroup) &&
-				  !$item['wall'] && !$item['origin'] && ($item['gravity'] == GRAVITY_PARENT)) {
-				Logger::info('Delete private group/communiy top-level item without mention', ['id' => $item['id'], 'guid'=> $item['guid']]);
+			if (!$mention) {
+				Logger::info('Top-level post without mention is deleted.', ['uri' => $item['uri'], $uid, 'id' => $item_id, 'uri-id' => $item['uri-id'], 'guid' => $item['guid']]);
 				Post\User::delete(['uri-id' => $item['uri-id'], 'uid' => $item['uid']]);
 				return true;
 			}
-			return false;
-		}
-
-		$arr = ['item' => $item, 'user' => $user];
-
-		Hook::callAll('tagged', $arr);
-
-		if (!$community_page && !$prvgroup) {
-			return false;
-		}
-
-		/*
-		 * tgroup delivery - setup a second delivery chain
-		 * prevent delivery looping - only proceed
-		 * if the message originated elsewhere and is a top-level post
-		 */
-		if ($item['wall'] || $item['origin'] || ($item['id'] != $item['parent'])) {
-			return false;
-		}
 
-		self::performActivity($item['id'], 'announce', $uid);
+			$arr = ['item' => $item, 'user' => $owner];
 
-		/**
-		 * All the following lines are only needed for private forums and compatibility to older systems without AP support.
-		 * A possible way would be that the followers list of a forum would always be readable by all followers.
-		 * So this would mean that the comment distribution could be done exactly for the intended audience.
-		 * Or possibly we could store the receivers that had been in the "announce" message above and use this.
-		 */
+			Hook::callAll('tagged', $arr);
+		} else {
+			$tags = Tag::getByURIId($item['parent-uri-id'], [Tag::MENTION, Tag::EXCLUSIVE_MENTION]);
+			foreach ($tags as $tag) {
+				if (Strings::compareLink($owner['url'], $tag['url'])) {
+					$mention = true;
+					Logger::info('Mention found in parent tag.', ['url' => $tag['url'], 'uri' => $item['uri'], 'uid' => $uid, 'id' => $item_id, 'uri-id' => $item['uri-id'], 'guid' => $item['guid']]);
+				}
+			}
 
-		// now change this copy of the post to a forum head message and deliver to all the tgroup members
-		$self = DBA::selectFirst('contact', ['id', 'name', 'url', 'thumb'], ['uid' => $uid, 'self' => true]);
-		if (!DBA::isResult($self)) {
-			return false;
+			if (!$mention) {
+				Logger::debug('No mentions found in parent, quitting here.', ['id' => $item_id, 'uri-id' => $item['uri-id'], 'guid' => $item['guid']]);
+				return false;
+			}
 		}
 
-		$owner_id = Contact::getIdForURL($self['url']);
+		Logger::info('Community post will be distributed', ['uri' => $item['uri'], 'uid' => $uid, 'id' => $item_id, 'uri-id' => $item['uri-id'], 'guid' => $item['guid']]);
 
-		// also reset all the privacy bits to the forum default permissions
-		if ($user['allow_cid'] || $user['allow_gid'] || $user['deny_cid'] || $user['deny_gid']) {
-			$private = self::PRIVATE;
-		} elseif (DI::pConfig()->get($user['uid'], 'system', 'unlisted')) {
-			$private = self::UNLISTED;
+		if ($owner['page-flags'] == User::PAGE_FLAGS_PRVGROUP) {
+			$allow_cid = '';
+			$allow_gid = '<' . Group::FOLLOWERS . '>';
+			$deny_cid  = '';
+			$deny_gid  = '';
+			self::performActivity($item['id'], 'announce', $uid, $allow_cid, $allow_gid, $deny_cid, $deny_gid);
 		} else {
-			$private = self::PUBLIC;
+			self::performActivity($item['id'], 'announce', $uid);
 		}
 
-		$permissionSet = DI::permissionSet()->selectOrCreate(
-			DI::permissionSetFactory()->createFromString(
-				$user['uid'],
-				$user['allow_cid'],
-				$user['allow_gid'],
-				$user['deny_cid'],
-				$user['deny_gid']
-			));
-
-		$forum_mode = ($prvgroup ? 2 : 1);
-
-		$fields = ['wall' => true, 'origin' => true, 'forum_mode' => $forum_mode, 'contact-id' => $self['id'],
-			'owner-id' => $owner_id, '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;
 	}
 
@@ -2334,12 +2375,17 @@ class Item
 	 *
 	 * Toggle activities as like,dislike,attend of an item
 	 *
-	 * @param int $item_id
+	 * @param int    $item_id
 	 * @param string $verb
 	 *            Activity verb. One of
 	 *            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
@@ -2347,7 +2393,7 @@ 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;
@@ -2508,10 +2554,10 @@ class Item
 			'body'          => $activity,
 			'verb'          => $activity,
 			'object-type'   => $objtype,
-			'allow_cid'     => $item['allow_cid'],
-			'allow_gid'     => $item['allow_gid'],
-			'deny_cid'      => $item['deny_cid'],
-			'deny_gid'      => $item['deny_gid'],
+			'allow_cid'     => $allow_cid ?? $item['allow_cid'],
+			'allow_gid'     => $allow_gid ?? $item['allow_gid'],
+			'deny_cid'      => $deny_cid ?? $item['deny_cid'],
+			'deny_gid'      => $deny_gid ?? $item['deny_gid'],
 			'visible'       => 1,
 			'unseen'        => 1,
 		];
@@ -3145,6 +3191,12 @@ class Item
 	 */
 	public static function getPlink($item)
 	{
+		if (!empty($item['plink']) && Network::isValidHttpUrl($item['plink'])) {
+			$plink = $item['plink'];
+		} elseif (!empty($item['uri']) && Network::isValidHttpUrl($item['uri']) && !Network::isLocalLink($item['uri'])) {
+			$plink = $item['uri'];
+		}
+
 		if (local_user()) {
 			$ret = [
 				'href' => "display/" . $item['guid'],
@@ -3153,14 +3205,14 @@ class Item
 				'orig_title' => DI::l10n()->t('View on separate page'),
 			];
 
-			if (!empty($item['plink'])) {
-				$ret['href'] = DI::baseUrl()->remove($item['plink']);
+			if (!empty($plink)) {
+				$ret['href'] = DI::baseUrl()->remove($plink);
 				$ret['title'] = DI::l10n()->t('Link to source');
 			}
-		} elseif (!empty($item['plink']) && ($item['private'] != self::PRIVATE)) {
+		} elseif (!empty($plink) && ($item['private'] != self::PRIVATE)) {
 			$ret = [
-				'href' => $item['plink'],
-				'orig' => $item['plink'],
+				'href' => $plink,
+				'orig' => $plink,
 				'title' => DI::l10n()->t('Link to source'),
 				'orig_title' => DI::l10n()->t('Link to source'),
 			];
@@ -3172,30 +3224,20 @@ class Item
 	}
 
 	/**
-	 * Is the given item array a post that is sent as starting post to a forum?
+	 * Does the given uri-id belongs to a post that is sent as starting post to a forum?
 	 *
-	 * @param array $item
-	 * @param array $owner
+	 * @param int $uri_id
 	 *
 	 * @return boolean "true" when it is a forum post
 	 */
-	public static function isForumPost(array $item, array $owner = [])
+	public static function isForumPost(int $uri_id)
 	{
-		if (empty($owner)) {
-			$owner = User::getOwnerDataById($item['uid']);
-			if (empty($owner)) {
-				return false;
+		foreach (Tag::getByURIId($uri_id, [Tag::EXCLUSIVE_MENTION]) as $tag) {
+			if (DBA::exists('contact', ['uid' => 0, 'nurl' => Strings::normaliseLink($tag['url']), 'contact-type' => Contact::TYPE_COMMUNITY])) {
+				return true;
 			}
 		}
-
-		if (($item['author-id'] == $item['owner-id']) ||
-			($owner['id'] == $item['contact-id']) ||
-			($item['uri-id'] != $item['parent-uri-id']) ||
-			$item['origin']) {
-			return false;
-		}
-
-		return Contact::isForum($item['contact-id']);
+		return false;
 	}
 
 	/**