mojo::Serialize*_() calls now propogate/return validation errors.

mojo/public/cpp/bindings/lib/map_serialization.h

Index: mojo/public/cpp/bindings/lib/map_serialization.h
diff --git a/mojo/public/cpp/bindings/lib/map_serialization.h b/mojo/public/cpp/bindings/lib/map_serialization.h
index 8ef83b3a3a554947606e20eb0aa01beaa53d06a5..db023f739151e4b8e8fc0ffcda4b345205320879 100644
--- a/mojo/public/cpp/bindings/lib/map_serialization.h
+++ b/mojo/public/cpp/bindings/lib/map_serialization.h
@@ -128,45 +128,54 @@ template <typename MapKey,
           typename MapValue,
           typename DataKey,
           typename DataValue>
-inline void SerializeMap_(
+inline internal::ValidationError SerializeMap_(
     Map<MapKey, MapValue>* input,
     internal::Buffer* buf,
     internal::Map_Data<DataKey, DataValue>** output,
     const internal::ArrayValidateParams* value_validate_params) {
-  if (input && *input) {
+  if (!input->is_null()) {

[viettrungluu, 2015/10/08 15:51:25]

I assume that |input| itself shouldn't be a null pointer (which the previous
code allowed).

I suggest you rewrite this as an early exit:

if (input->is_null()) {
  // In this case, |output| is just serialized as null.
  *output = nullptr;
  return VALIDATION_ERROR_NONE;
}

[vardhan, 2015/10/08 20:53:51]

That's right, thought i'd fix it here.
Done.

     internal::Map_Data<DataKey, DataValue>* result =
         internal::Map_Data<DataKey, DataValue>::New(buf);
+
+    // We *must* serialize the keys before we allocate an Array_Data for the
+    // values.
     internal::Array_Data<DataKey>* keys_data =
         internal::Array_Data<DataKey>::New(input->size(), buf);
+    result->keys.ptr = keys_data;
+
+    internal::MapKeyIterator<MapKey, MapValue> key_iter(input);
+    const internal::ArrayValidateParams* key_validate_params =
+        internal::MapKeyValidateParamsFactory<DataKey>::Get();
+
+    auto keys_retval =
+        internal::ArraySerializer<MapKey, DataKey>::SerializeElements(
+            key_iter.begin(), input->size(), buf, result->keys.ptr,
+            key_validate_params);
+    if (keys_retval != internal::ValidationError::VALIDATION_ERROR_NONE)
+      return keys_retval;
+
+    // Now we try allocate an Array_Data for the values
+    internal::Array_Data<DataValue>* values_data =
+        internal::Array_Data<DataValue>::New(input->size(), buf);
+    result->values.ptr = values_data;
 
-    if (result && keys_data) {
-      result->keys.ptr = keys_data;
-
-      // We *must* serialize the keys before we allocate an Array_Data for the
-      // values.
-      internal::MapKeyIterator<MapKey, MapValue> key_iter(input);
-      const internal::ArrayValidateParams* key_validate_params =
-          internal::MapKeyValidateParamsFactory<DataKey>::Get();
-
-      internal::ArraySerializer<MapKey, DataKey>::SerializeElements(
-          key_iter.begin(), input->size(), buf, result->keys.ptr,
-          key_validate_params);
-
-      // Now we try allocate an Array_Data for the values
-      internal::Array_Data<DataValue>* values_data =
-          internal::Array_Data<DataValue>::New(input->size(), buf);
-      if (values_data) {
-        result->values.ptr = values_data;
-        internal::MapValueIterator<MapKey, MapValue> value_iter(input);
+    internal::MapValueIterator<MapKey, MapValue> value_iter(input);
+
+    auto values_retval =
         internal::ArraySerializer<MapValue, DataValue>::SerializeElements(
             value_iter.begin(), input->size(), buf, result->values.ptr,
             value_validate_params);
-      }
-    }
+
+    if (values_retval != internal::ValidationError::VALIDATION_ERROR_NONE)
+      return values_retval;
+
     *output = result;
   } else {
+    // |input| could be a nullable map, in which case |output| is serialized as
+    // null, which is valid.
     *output = nullptr;
   }
+  return internal::ValidationError::VALIDATION_ERROR_NONE;
 }
 
 template <typename MapKey,