Handle callback errors

src/posts/flags.js

@@ -106,6 +106,10 @@ module.exports = function(Posts) {
 						async.series([
 							function(next) {
 								db.getSortedSetRange('pid:' + pid + ':flag:uids', 0, -1, function(err, uids) {
+									if (err) {
+										return next(err);
+									}
+
 									async.each(uids, function(uid, next) {
 										var nid = 'post_flag:' + pid + ':uid:' + uid;
 										async.parallel([

src/posts/summary.js

@@ -101,6 +101,10 @@ module.exports = function(Posts) {
 						next(null, post);
 					});
 				}, function(err, posts) {
+					if (err) {
+						return callback(err);
+					}
+
 					plugins.fireHook('filter:post.getPostSummaryByPids', {posts: posts, uid: uid}, function(err, postData) {
 						callback(err, postData.posts);
 					});