Properly handle leading zeros in pub version numbers.

sdk/lib/_internal/pub/test/version_test.dart

Index: sdk/lib/_internal/pub/test/version_test.dart
diff --git a/sdk/lib/_internal/pub/test/version_test.dart b/sdk/lib/_internal/pub/test/version_test.dart
index ee00e6ebb048680cc375f225f91ae7d9999a829b..f2c8c2c35303ffe20086ff886afeae5fec7a4471 100644
--- a/sdk/lib/_internal/pub/test/version_test.dart
+++ b/sdk/lib/_internal/pub/test/version_test.dart
@@ -80,6 +80,16 @@ main() {
           }
         }
       });
+
+      test('equality', () {
+        expect(new Version.parse('01.2.3'), equals(new Version.parse('1.2.3')));
+        expect(new Version.parse('1.02.3'), equals(new Version.parse('1.2.3')));
+        expect(new Version.parse('1.2.03'), equals(new Version.parse('1.2.3')));
+        expect(new Version.parse('1.2.3-01'),
+            equals(new Version.parse('1.2.3-1')));
+        expect(new Version.parse('1.2.3+01'),
+            equals(new Version.parse('1.2.3+1')));
+      });
     });
 
     test('allows()', () {