ALTER PROTO BUNDLE after CREATE TABLE sometimes causes internal error when reading a proto bundle

[hugosandelius]

To reproduce, run:

CREATE PROTO BUNDLE (`myproto.MyType`)
CREATE TABLE MyTypeTable (
   my_type `myproto.MyType`,
  ...
)
ALTER PROTO BUNDLE INSERT (`myproto.OtherType`)

then do an insert followed by a read against MyTypeTable.
Sometimes in response to the read you will receive the following error from Spanner client:

spanner: code = “Internal”, desc = “grpc: failed to unmarshal the received message: string field contains invalid UTF-8"

and see the following log from spanner emulator:

[wire_format_lite.cc:626] String field ‘google.spanner.v1.Type.proto_type_fqn’ contains invalid UTF-8 data when serializing a protocol buffer. Use the ‘bytes’ type if you intend to send raw bytes.

It does not always happen. It does not seem to happen if the ALTER PROTO BUNDLE INSERT statement is before the CREATE TABLE statement.