Update descriptor protos

1 files changed, 6 insertions, 0 deletions

diff --git a/csharp/src/Google.Protobuf/WellKnownTypes/FieldMask.cs b/csharp/src/Google.Protobuf/WellKnownTypes/FieldMask.cs
index ef3bc10a..ee4561ff 100644
--- a/csharp/src/Google.Protobuf/WellKnownTypes/FieldMask.cs
+++ b/csharp/src/Google.Protobuf/WellKnownTypes/FieldMask.cs
@@ -239,6 +239,12 @@ namespace Google.Protobuf.WellKnownTypes {
   ///
   /// Note that oneof type names ("test_oneof" in this case) cannot be used in
   /// paths.
+  ///
+  /// ## Field Mask Verification
+  ///
+  /// The implementation of the all the API methods, which have any FieldMask type
+  /// field in the request, should verify the included field paths, and return
+  /// `INVALID_ARGUMENT` error if any path is duplicated or unmappable.
   /// </summary>
   public sealed partial class FieldMask : pb::IMessage<FieldMask> {
     private static readonly pb::MessageParser<FieldMask> _parser = new pb::MessageParser<FieldMask>(() => new FieldMask());