From e06700a8ff17afd011891f52e148da8dcf84ee2f Mon Sep 17 00:00:00 2001
From: John Brooks <john.brooks@dereferenced.net>
Date: Sun, 23 Oct 2016 08:22:52 -0700
Subject: [PATCH] Fix a race condition in Refresh and wrapWriter

These functions would bypass calling RuneBuffer.Refresh when
Terminal.IsReading(), but this leads to a race condition when another
goroutine is just beginning to read. The result is that the prompt is
not erased or rewritten in some cases.

RuneBuffer.Refresh protects this with a mutex, and looks safe to call
even when !IsReading(), so removing these redundant checks seems
sufficient.

The tested scenario is to have goroutine A calling Readline in a loop
and handling commands, and goroutine B periodically printing to
Instance.Stdout(). If the print in B is timed just before A calls
Readline, the printed line is displayed after the prompt and the prompt
is not reprinted until the next input.
---
 operation.go | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/operation.go b/operation.go
index 2c93561..497e6c6 100644
--- a/operation.go
+++ b/operation.go
@@ -43,10 +43,6 @@ type wrapWriter struct {
 }
 
 func (w *wrapWriter) Write(b []byte) (int, error) {
-	if !w.t.IsReading() {
-		return w.target.Write(b)
-	}
-
 	var (
 		n   int
 		err error
@@ -478,9 +474,7 @@ func (o *Operation) SaveHistory(content string) error {
 }
 
 func (o *Operation) Refresh() {
-	if o.t.IsReading() {
-		o.buf.Refresh(nil)
-	}
+	o.buf.Refresh(nil)
 }
 
 func (o *Operation) Clean() {