From 19a6dc1ba40c91badb8a5372bffffff902bb399e Mon Sep 17 00:00:00 2001
From: lpproj <lpproj@gmail.com>
Date: Fri, 27 Dec 2019 17:41:51 +0900
Subject: [PATCH] Fix func 0Bh (Get STDIN Status) always returns AL=FFh with
 some alternative CON drivers:

* qwikansi.sys (simtelnet: simtelnet/msdos/screen/qwikansi.zip
* most of Japanese input methods (Microsoft MS-IME, ATOK, WXP/WX2/WX3)
---
 kernel/chario.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/kernel/chario.c b/kernel/chario.c
index 3f3d1c2..b5853d5 100644
--- a/kernel/chario.c
+++ b/kernel/chario.c
@@ -96,7 +96,9 @@ STATIC void CharCmd(struct dhdr FAR **pdev, unsigned command)
 
 STATIC int Busy(struct dhdr FAR **pdev)
 {
-  CharCmd(pdev, C_ISTAT);
+  CharCmd(pdev, C_NDREAD);
+  if (CharReqHdr.r_status & S_ERROR)
+    CharCmd(pdev, C_ISTAT);
   return CharReqHdr.r_status & S_BUSY;
 }