Ignore duplicates in insertBefore (#1628)

Fix #1525 and implement option number 2.

Author: RunDevelopment

components/prism-core.js

@@ -96,7 +96,7 @@ var _ = _self.Prism = {
 		/**
 		 * Insert a token before another token in a language literal
 		 * As this needs to recreate the object (we cannot actually insert before keys in object literals),
-		 * we cannot just provide an object, we need anobject and a key.
+		 * we cannot just provide an object, we need an object and a key.
 		 * @param inside The key (or language id) of the parent
 		 * @param before The key to insert before.
 		 * @param insert Object with the key/value pairs to insert
@@ -108,20 +108,20 @@ var _ = _self.Prism = {
 			var ret = {};
 
 			for (var token in grammar) {
-
 				if (grammar.hasOwnProperty(token)) {
 
 					if (token == before) {
-
 						for (var newToken in insert) {
-
 							if (insert.hasOwnProperty(newToken)) {
 								ret[newToken] = insert[newToken];
 							}
 						}
 					}
 
-					ret[token] = grammar[token];
+					// Do not insert token which also occur in insert. See #1525
+					if (!insert.hasOwnProperty(token)) {
+						ret[token] = grammar[token];
+					}
 				}
 			}
 

components/prism-core.min.js

@@ -12,7 +12,6 @@ Prism.languages.jolie = Prism.languages.extend('clike', {
 });
 
 delete Prism.languages.jolie['class-name'];
-delete Prism.languages.jolie['function'];
 
 Prism.languages.insertBefore( 'jolie', 'keyword', {
 	'function':