From 236cf308c298b49d64d32a76f5ee242a2b3bc1b4 Mon Sep 17 00:00:00 2001
From: Robert Griesemer <gri@golang.org>
Date: Mon, 25 Aug 2014 15:29:47 -0700
Subject: [PATCH] cmd/gofmt: don't permit -w with stdin

Also: use 0x644 file permission if a new file
is created (should not happen anymore, though).

LGTM=r
R=r
CC=golang-codereviews
https://golang.org/cl/126610044
---
 src/cmd/gofmt/gofmt.go | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/cmd/gofmt/gofmt.go b/src/cmd/gofmt/gofmt.go
index f7d30d84052..f322a2b0a07 100644
--- a/src/cmd/gofmt/gofmt.go
+++ b/src/cmd/gofmt/gofmt.go
@@ -122,7 +122,7 @@ func processFile(filename string, in io.Reader, out io.Writer, stdin bool) error
 			fmt.Fprintln(out, filename)
 		}
 		if *write {
-			err = ioutil.WriteFile(filename, res, 0)
+			err = ioutil.WriteFile(filename, res, 0644)
 			if err != nil {
 				return err
 			}
@@ -186,6 +186,11 @@ func gofmtMain() {
 	initRewrite()
 
 	if flag.NArg() == 0 {
+		if *write {
+			fmt.Fprintln(os.Stderr, "error: cannot use -w with standard input")
+			exitCode = 2
+			return
+		}
 		if err := processFile("<standard input>", os.Stdin, os.Stdout, true); err != nil {
 			report(err)
 		}