Validate that headers contain legal bytes
diff --git a/include/grpc/grpc.h b/include/grpc/grpc.h
index 9bb826f..3348653 100644
--- a/include/grpc/grpc.h
+++ b/include/grpc/grpc.h
@@ -140,7 +140,9 @@
/* there is already an outstanding read/write operation on the call */
GRPC_CALL_ERROR_TOO_MANY_OPERATIONS,
/* the flags value was illegal for this call */
- GRPC_CALL_ERROR_INVALID_FLAGS
+ GRPC_CALL_ERROR_INVALID_FLAGS,
+ /* invalid metadata was passed to this call */
+ GRPC_CALL_ERROR_INVALID_METADATA
} grpc_call_error;
/* Result of a grpc operation */