Fix RocketChat/Rocket.Chat#329. Check for duplicate name before creating

channel or private group

Queried ChatRoom for Room with same name and returned a descriptive
error if one was found when creating a Channel or Private Group.

server/methods/createChannel.coffee

@@ -13,6 +13,10 @@ Meteor.methods
 
 		members.push user.username
 
+		# avoid duplicate names
+		if ChatRoom.findOne({name:name})
+			throw new Meteor.Error 'duplicate-name', "A Channel with the same name exists"
+
 		# name = s.slugify name
 
 		room =

server/methods/createPrivateGroup.coffee

@@ -13,6 +13,10 @@ Meteor.methods
 
 		name = s.slugify name
 
+		# avoid duplicate names
+		if ChatRoom.findOne({name:name})
+			throw new Meteor.Error 'duplicate-name', "A private group with the same name exists"
+
 		# create new room
 		rid = ChatRoom.insert
 			usernames: members