Join terminal event polling on shutdown

uiterm/ui.go

@@ -100,15 +100,32 @@ func (ui *Ui) Run(cmds chan string) error {
 	if err := termbox.Init(); err != nil {
 		return err
 	}
-	defer termbox.Close()
 	termbox.SetInputMode(termbox.InputAlt)
 
-	events := make(chan termbox.Event)
+	// Closing termbox wakes PollEvent. Keep delivery cancellable so the polling
+	// goroutine cannot become stranded trying to send after Run returns.
+	events := make(chan termbox.Event, 1)
+	pollDone := make(chan struct{})
 	go func() {
+		defer close(pollDone)
 		for {
-			events <- termbox.PollEvent()
+			event := termbox.PollEvent()
+			select {
+			case <-ui.close:
+				return
+			default:
+			}
+			select {
+			case events <- event:
+			case <-ui.close:
+				return
+			}
 		}
 	}()
+	defer func() {
+		termbox.Close()
+		<-pollDone
+	}()
 
 	ui.manager.OnUiInitialize(ui)
 	ui.manager.OnUiDoneInitialize(ui)