drop message sends if message has no return instead of throw error

scripts/core/engine.js

@@ -509,7 +509,11 @@ function actor_prep(actor, send) {
 }
 
 function actor_send(actor, message) {
-  if (!is_actor(actor)) throw new Error(`Must send to an actor object. Attempted send to ${json.encode(actor)}`)
+  if (actor[HEADER] && !actor[HEADER].replycc) // attempting to respond to a message but sender is not expecting; silently drop
+    return
+
+  if (!is_actor(actor) ) throw new Error(`Must send to an actor object. Attempted send to ${json.encode(actor)}`)
+  
   if (typeof message !== 'object') throw new Error('Must send an object record.')
 
   // message to self

tests/sdl_video.js

@@ -19,7 +19,7 @@ send(act, {kind:"window", op: "create"}, ({id}) => {
     renderer = id
     console.log(`made renderer with id ${id}`)
     
-    send(act, {kind:"renderer", id: renderer, op:"set", prop: "drawColor", value:[0.6,0.4,0.5,1]}, handle_response)
+    send(act, {kind:"renderer", id: renderer, op:"set", prop: "drawColor", value:[0.6,0.4,0.5,1]})
     send(act, {kind:"renderer", id: renderer, op:"clear"}, handle_response)
     send(act, {kind:"renderer", id: renderer, op: "present"}, handle_response)
   })