closes #6672

public/language/en-GB/global.json

@@ -108,6 +108,7 @@
 
 	"guest": "Guest",
 	"guests": "Guests",
+	"former_user": "A Former User",
 
 	"updated.title": "Forum Updated",
 	"updated.message": "This forum has just been updated to the latest version. Click here to refresh the page.",

src/user/data.js

@@ -119,6 +119,11 @@ module.exports = function (User) {
 			return memo;
 		}, {});
 		var users = uids.map(function (uid) {
+			const returnPayload = usersData[ref[uid]];
+			if (uid > 0 && !returnPayload.uid) {
+				returnPayload.oldUid = parseInt(uid, 10);
+			}
+
 			return usersData[ref[uid]];
 		});
 		return users;
@@ -144,7 +149,7 @@ module.exports = function (User) {
 
 			if (!parseInt(user.uid, 10)) {
 				user.uid = 0;
-				user.username = '[[global:guest]]';
+				user.username = (user.hasOwnProperty('oldUid') && parseInt(user.oldUid, 10)) ? '[[global:former_user]]' : '[[global:guest]]';
 				user.userslug = '';
 				user.picture = User.getDefaultAvatar();
 				user['icon:text'] = '?';