Fix pub_lish_test.

utils/pub/utils.dart

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 /// Generic utility functions. Stuff that should possibly be in core.
 library utils;
 
 import 'dart:async';
 import 'dart:crypto';
 import 'dart:isolate';
@@ skipping 300 matching lines @@
 }
 
 // TODO(nweiz): remove this when issue 9068 has been fixed.
 /// Whether [uri1] and [uri2] are equal. This consider HTTP URIs to default to
 /// port 80, and HTTPs URIs to default to port 443.
 bool urisEqual(Uri uri1, Uri uri2) =>
   canonicalizeUri(uri1) == canonicalizeUri(uri2);
 
 /// Return [uri] with redundant port information removed.
 Uri canonicalizeUri(Uri uri) {
+  if (uri == null) return null;
+
   var sansPort = new Uri.fromComponents(
       scheme: uri.scheme, userInfo: uri.userInfo, domain: uri.domain,
       path: uri.path, query: uri.query, fragment: uri.fragment);
   if (uri.scheme == 'http' && uri.port == 80) return sansPort;
   if (uri.scheme == 'https' && uri.port == 443) return sansPort;
   return uri;
 }
 
 /// Add all key/value pairs from [source] to [destination], overwriting any
 /// pre-existing values.
 void mapAddAll(Map destination, Map source) =>
   source.forEach((key, value) => destination[key] = value);
 
 /// Decodes a URL-encoded string. Unlike [decodeUriComponent], this includes
 /// replacing `+` with ` `.
 String urlDecode(String encoded) =>
   decodeUriComponent(encoded.replaceAll("+", " "));