Feedback, and copy string-slices into byte-arrays.

include/toit/toit.h

@@ -62,8 +62,8 @@ typedef toit_err_t (*toit_msg_on_created_cb_t)(void* user_data, toit_msg_context
  * service) to this service.
  *
  * The data is owned by the receiver and must be freed.
- * If the Toit side sent a string, then the data is guaranteed to be null-terminated. The
- * length does *not* include the null-terminator.
+ * If the Toit side sent a string, then the data is guaranteed to be 0-terminated. The
+ * length does *not* include the 0-terminator.
  *
  * @param user_data The user data passed to `toit_msg_add_handler`.
  * @param sender The PID of the sender.
@@ -87,8 +87,8 @@ typedef toit_err_t (*toit_msg_on_message_cb_t)(void* user_data, int sender, uint
  * It is an error to not reply to the request, or to reply more than once.
  *
  * The data is owned by the receiver and must be freed.
- * If the Toit side sent a string, then the data is guaranteed to be null-terminated. The
- * length does *not* include the null-terminator.
+ * If the Toit side sent a string, then the data is guaranteed to be 0-terminated. The
+ * length does *not* include the 0-terminator.
  *
  * @param user_data The user data passed to `toit_msg_add_handler`.
  * @param sender The PID of the sender.

lib/system/external.toit

@@ -67,9 +67,8 @@ class Client:
   /** Helper to convert the $message to a string or ByteArray. */
   encode-message_ message/io.Data --copy/bool -> io.Data:
     bytes/ByteArray := ?
-    if message is string:
-      // By taking a copy we ensure that we don't have to worry about string slices.
-      return (message as string).copy
+    if message is string and message is not StringSlice_:
+      return message
     if not copy and message is ByteArray:
       return message
     bytes = ByteArray message.byte-size