some checks for purge

src/posts.js

@@ -102,6 +102,10 @@ var async = require('async'),
 		], callback);
 	};
 
+	Posts.exists = function(pid, callback) {
+		db.isSortedSetMember('posts:pid', pid, callback);
+	};
+
 	Posts.getPostsByTid = function(tid, set, start, end, uid, reverse, callback) {
 		Posts.getPidsFromSet(set, start, end, reverse, function(err, pids) {
 			if(err) {

src/posts/delete.js

@@ -102,6 +102,11 @@ module.exports = function(Posts) {
 	}
 
 	Posts.purge = function(pid, callback) {
+		Posts.exists(pid, function(err, exists) {
+			if (err || !exists) {
+				return callback(err);
+			}
+
 			async.parallel([
 				function(next) {
 					deletePostFromTopicAndUser(pid, next);
@@ -126,6 +131,7 @@ module.exports = function(Posts) {
 				plugins.fireHook('action:post.delete', pid);
 				db.delete('post:' + pid, callback);
 			});
+		});
 	};
 
 	function deletePostFromTopicAndUser(pid, callback) {

src/socket.io/posts.js

@@ -227,7 +227,7 @@ function deleteOrRestore(command, socket, data, callback) {
 }
 
 SocketPosts.purge = function(socket, data, callback) {
-	if(!data) {
+	if(!data || !parseInt(data.pid, 10)) {
 		return callback(new Error('[[error:invalid-data]]'));
 	}
 	postTools.purge(socket.uid, data.pid, function(err) {

src/socket.io/topics.js

@@ -240,6 +240,9 @@ SocketTopics.unpin = function(socket, data, callback) {
 };
 
 function doTopicAction(action, socket, data, callback) {
+	if (!socket.uid) {
+		return;
+	}
 	if(!data || !Array.isArray(data.tids) || !data.cid) {
 		return callback(new Error('[[error:invalid-tid]]'));
 	}

src/threadTools.js

@@ -72,6 +72,11 @@ var winston = require('winston'),
 	}
 
 	ThreadTools.purge = function(tid, uid, callback) {
+		ThreadTools.exists(tid, function(err, exists) {
+			if (err || !exists) {
+				return callback(err);
+			}
+
 			batch.processSortedSet('tid:' + tid + ':posts', function(pids, next) {
 				async.eachLimit(pids, 10, posts.purge, next);
 			}, {alwaysStartAt: 0}, function(err) {
@@ -91,6 +96,7 @@ var winston = require('winston'),
 					});
 				});
 			});
+		});
 	};
 
 	ThreadTools.lock = function(tid, uid, callback) {