#4929: Fix type mismatch in usage of e107forum::getForumClassMembers()

Also, `e107forum::getForumClassMembers()` is now documented and
deprecated because it has unintuitive return values.

Fixes: #4929

e107_plugins/forum/forum_class.php

@@ -174,6 +174,22 @@ function getForumSef($threadInfo)
 
 	}
 
+	/**
+	 * Get an array of the first alphabetical 50 usernames, user IDs, and the users' serialized user classes that match
+	 * the forum's allowed viewers or a user class ID if the allowed viewers is a special user class except if the
+	 * special user class is {@see e_UC_MAINADMIN} or {@see false} if the previous two possibilities are not encountered
+	 *
+	 * @deprecated v2.3.3 Due to the confusing usage, consider writing another method to get the list of members that
+	 *                    can see the forum identified by its forum ID.
+	 * @param $forumId int The ID from `e107_forum`.`forum_id`
+	 * @param $type string Can only be "view"
+	 * @return array|int|false When an array, the first 50 users, sorted alphabetically by username, that can view this
+	 *                         forum, along with their user ID, username, and serialized user classes.
+	 *                         When an int, the special user class ID as defined in {@see e107::set_constants()} except
+	 *                         {@see e_UC_MAINADMIN}.
+	 *                         When boolean false, this is an unhandled case probably due to the
+	 *                         `e107_forum`.`forum_class` column missing from the table.
+	 */
 	function getForumClassMembers($forumId, $type='view')
 	{
 

e107_plugins/forum/shortcodes/batch/viewforum_shortcodes.php

@@ -239,29 +239,26 @@ function sc_viewable_by()
 		{
 			global $forum, $forumId;
 
-			if($users = $forum->getForumClassMembers($forumId))
+			if($usersOrUserClassId = $forum->getForumClassMembers($forumId))
 			{
 				$userList = array();
-				$viewable = e107::getUserClass()->getFixedClassDescription($users);
-				if(is_array($users))
+				if(is_array($usersOrUserClassId))
 				{
-					foreach($users as $user)
+					foreach($usersOrUserClassId as $user)
 					{
 						$userList[] = "<a href='" . e107::getUrl()->create('user/profile/view', $user) . "'>" . $user['user_name'] . "</a>";
 					}
 
 					$viewable = implode(', ', $userList);;
 				}
-				elseif($users == 0)
+				elseif($usersOrUserClassId == 0)
 				{
 					$viewable = '';
 				}
-				/*--
-					else
-					{
-						$viewable =  e107::getUserClass()->getFixedClassDescription($users);
-					}
-				--*/
+				else
+				{
+					$viewable = e107::getUserClass()->getFixedClassDescription($usersOrUserClassId);
+				}
 			}
 
 			/*--