From c2428b8bf6f3646f575c21d0c89192d79130f7cc Mon Sep 17 00:00:00 2001
From: Nobuyoshi Nakada <nobu@ruby-lang.org>
Date: Mon, 29 Jul 2019 23:04:04 +0900
Subject: [PATCH] Erase only on tty

---
 bootstraptest/runner.rb | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/bootstraptest/runner.rb b/bootstraptest/runner.rb
index 4e9196ef3d..56b4b12230 100755
--- a/bootstraptest/runner.rb
+++ b/bootstraptest/runner.rb
@@ -171,8 +171,8 @@ End
 end
 
 def erase(e = true)
-  if e and @columns > 0 and !@verbose
-    "\r#{" "*@columns}\r"
+  if e and @columns > 0 and @tty and !@verbose
+    "\e[1K\r"
   else
     ""
   end