pass on mainPid

src/topics.js

@@ -216,7 +216,7 @@ var async = require('async'),
 
 			async.parallel({
 				mainPost: function(next) {
-					Topics.getMainPost(tid, uid, next);
+					getMainPosts([topicData.mainPid], uid, next);
 				},
 				posts: function(next) {
 					Topics.getTopicPosts(tid, set, start, end, uid, reverse, next);
@@ -230,7 +230,7 @@ var async = require('async'),
 					return callback(err);
 				}
 
-				topicData.posts = results.mainPost ? [results.mainPost].concat(results.posts) : results.posts;
+				topicData.posts = Array.isArray(results.mainPost) && results.mainPost.length ? [results.mainPost[0]].concat(results.posts) : results.posts;
 				topicData.category = results.category;
 				topicData.thread_tools = results.threadTools;
 				topicData.tags = results.tags;
@@ -262,19 +262,23 @@ var async = require('async'),
 				return topic ? topic.mainPid : null;
 			});
 
-			posts.getPostsByPids(mainPids, uid, function(err, postData) {
-				if (err) {
-					return callback(err);
+			getMainPosts(mainPids, uid, callback);
+		});
+	};
+
+	function getMainPosts(mainPids, uid, callback) {
+		posts.getPostsByPids(mainPids, uid, function(err, postData) {
+			if (err) {
+				return callback(err);
+			}
+			postData.forEach(function(post) {
+				if (post) {
+					post.index = 0;
 				}
-				postData.forEach(function(post) {
-					if (post) {
-						post.index = 0;
-					}
-				});
-				Topics.addPostData(postData, uid, callback);
 			});
+			Topics.addPostData(postData, uid, callback);
 		});
-	};
+	}
 
 	Topics.getTopicField = function(tid, field, callback) {
 		db.getObjectField('topic:' + tid, field, callback);