Update hashCode to hash the entire message

lib/unknown_field_set.dart

 // Copyright (c) 2011, 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.
 
 part of protobuf;
 
 class UnknownFieldSet {
 
   final Map<int, UnknownFieldSetField> _fields =
       new Map<int, UnknownFieldSetField>();
@@ skipping 102 matching lines @@
     return _fields.putIfAbsent(number, () => new UnknownFieldSetField());
   }
 
   bool operator ==(other) {
     if (other is! UnknownFieldSet) return false;
 
     UnknownFieldSet o = other;
     return _areMapsEqual(o._fields, _fields);
   }
 
-  int get hashCode => _fields.hashCode;
+  int get hashCode {
+    int hash = 0;
+    _fields.forEach((number, value) {
+      hash = ((37 * hash) + number) & 0x3fffffff;
+      hash = ((53 * hash) + value.hashCode) & 0x3fffffff;
+    });
+    return hash;
+  }
 
   String toString() => _toString('');
 
   String _toString(String indent) {
     var stringBuffer = new StringBuffer();
 
     for (int tag in sorted(_fields.keys)) {
       var field = _fields[tag];
       for (var value in field.values) {
         if (value is UnknownFieldSet) {
@@ skipping 40 matching lines @@
       }
     }
     if (!_areListsEqual(o.varints, varints)) return false;
     if (!_areListsEqual(o.fixed32s, fixed32s)) return false;
     if (!_areListsEqual(o.fixed64s, fixed64s)) return false;
     if (!_areListsEqual(o.groups, groups)) return false;
 
     return true;
   }
 
-  int get hashCode => lengthDelimited.hashCode;
+  int get hashCode {
+    int hash = 0;
+    lengthDelimited.forEach((value) {
+      for (int i = 0; i < value.length; i++) {
+        hash = (hash + value[i]) & 0x3fffffff;
+        hash = (hash + hash << 10) & 0x3fffffff;
+        hash = (hash ^ hash >> 6) & 0x3fffffff;
+      }
+      hash = (hash + hash << 3) & 0x3fffffff;
+      hash = (hash ^ hash >> 11) & 0x3fffffff;
+      hash = (hash + hash << 15) & 0x3fffffff;
+    });
+    varints.forEach(
+        (value) => hash = (hash + 7 * value.hashCode) & 0x3fffffff);
+    fixed32s.forEach(
+        (value) => hash = (hash + 37 * value.hashCode) & 0x3fffffff);
+    fixed64s.forEach(
+        (value) => hash = (hash + 53 * value.hashCode) & 0x3fffffff);
+    groups.forEach(
+        (value) => hash = (hash + value.hashCode) & 0x3fffffff);
+    return hash;
+  }
 
   List get values => []
       ..addAll(lengthDelimited)
       ..addAll(varints)
       ..addAll(fixed32s)
       ..addAll(fixed64s)
       ..addAll(groups);
 
   void writeTo(int fieldNumber, CodedBufferWriter output) {
     write(type, value) {
@@ skipping 26 matching lines @@
   void addVarint(Int64 value) {
     varints.add(value);
   }
 
   bool hasRequiredFields() => false;
 
   bool isInitialized() => true;
 
   int get length => values.length;
 }