From a65f861bfa7a393e61cbe7aad0d1ecd42a0237be Mon Sep 17 00:00:00 2001
From: Alex Brainman <alex.brainman@gmail.com>
Date: Thu, 16 May 2013 17:20:13 +1000
Subject: [PATCH] os: use small buffer when reading from windows console

Fixes #5481.

R=golang-dev, dominik.honnef, bradfitz
CC=golang-dev
https://golang.org/cl/9437044
---
 src/pkg/os/file_windows.go | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/src/pkg/os/file_windows.go b/src/pkg/os/file_windows.go
index 82af756d89..41233fff64 100644
--- a/src/pkg/os/file_windows.go
+++ b/src/pkg/os/file_windows.go
@@ -251,8 +251,14 @@ func (f *File) readConsole(b []byte) (n int, err error) {
 		return 0, nil
 	}
 	if len(f.readbuf) == 0 {
+		// syscall.ReadConsole seems to fail, if given large buffer.
+		// So limit the buffer to 16000 characters.
+		readN := 16000
+		if len(b) < readN {
+			readN = len(b)
+		}
 		// get more input data from os
-		wchars := make([]uint16, len(b))
+		wchars := make([]uint16, readN)
 		var p *uint16
 		if len(b) > 0 {
 			p = &wchars[0]
-- 
2.48.1