baseURL sanitize fix, addToError avoid mutation, set System.constructor

Author: guybedford

src/system.js

@@ -29,9 +29,8 @@ function SystemLoader(options) {
     }
 
     // sanitize out the hash and querystring
-    // removes the username and password, which could be adjusted
-    baseURL = new URL(baseURL);
-    baseURL = baseURL.origin + baseURL.pathname.substr(0, baseURL.pathname.lastIndexOf('/') + 1);
+    baseURL = baseURL.split('#')[0].split('?')[0];
+    baseURL = baseURL.substr(0, baseURL.lastIndexOf('/') + 1);
   }
   else if (typeof process != 'undefined' && process.cwd) {
     baseURL = 'file://' + (isWindows ? '/' : '') + process.cwd() + '/';

src/wrapper-end.js

@@ -8,8 +8,10 @@
   __global.Reflect.global = __global.Reflect.global || __global;
   __global.LoaderPolyfill = Loader;
 
-  if (!System)
+  if (!System) {
     System = new SystemLoader();
+    System.constructor = SystemLoader;
+  }
 
   if (typeof exports === 'object')
     module.exports = System;

src/wrapper-start.js

@@ -34,11 +34,17 @@
   })();
 
   function addToError(err, msg) {
-    if (err instanceof Error)
-      err.message = err.message + '\n\t' + msg;
-    else
-      err = err + '\n\t' + msg;
-    return err;
+    var newErr;
+    if (err instanceof Error) {
+      var newErr = new err.constructor(err.message, err.fileName, err.lineNumber);
+      newErr.message = err.message + '\n\t' + msg;
+      newErr.stack = err.stack;
+    }
+    else {
+      newErr = err + '\n\t' + msg;
+    }
+      
+    return newErr;
   }
 
   function __eval(source, debugName, context) {