Merge pull request #1300 from mathjax/fix/pack

Fix regex for quoting file names to include

Author: dpvc

components/bin/pack

@@ -42,7 +42,7 @@ const bundle = (process.argv[3] || 'bundle');
  * @return {RegExp}        The regular expression for the name,
  */
 function fileRegExp(name) {
-  return new RegExp(name.replace(/([\\.{}[\]()?*^$])/g, '\\$1'), 'g');
+  return new RegExp(name.replace(/([\\.{}[\]()?*+^$])/g, '\\$1'), 'g');
 }
 
 /**

components/webpack.common.cjs

@@ -35,7 +35,7 @@ const DIRNAME = __dirname;
  * @return {string}        The string with regex special characters escaped
  */
 function quoteRE(string) {
-  return string.replace(/([\\.{}[\]()?*^$])/g, '\\$1');
+  return string.replace(/([\\.{}[\]()?*+^$])/g, '\\$1');
 }
 
 /****************************************************************/