Force processing of context cancellation first

Author: hannahhoward

hamt/hamt.go

@@ -483,6 +483,11 @@ func makeAsyncTrieGetLinks(dagService ipld.DAGService, linkResults chan<- format
 }
 
 func emitResult(ctx context.Context, linkResults chan<- format.LinkResult, r format.LinkResult) {
+	select {
+	case <-ctx.Done():
+		return
+	default:
+	}
 	select {
 	case linkResults <- r:
 	case <-ctx.Done():