closes #1947

src/controllers/tags.js

@@ -13,7 +13,7 @@ tagsController.getTag = function(req, res, next) {
 			return next(err);
 		}
 
-		if (!tids || !tids.length) {
+		if (Array.isArray(tids) && !tids.length) {
 			topics.deleteTag(tag);
 			return res.render('tag', {topics: [], tag:tag});
 		}

src/topics/tags.js

@@ -47,7 +47,6 @@ module.exports = function(Topics) {
 			return '';
 		}
 		tag = tag.trim().toLowerCase();
-		tag = tag.replace(/&/g, '&');
 		tag = tag.replace(/[,\/#!$%\^\*;:{}=_`<>'"~()?\|]/g, '');
 		tag = tag.substr(0, meta.config.maximumTagLength || 15);
 		var matches = tag.match(/^[.-]*(.+?)[.-]*$/);