From 735780c27ee72a4a2cdfac306118cf015d922c93 Mon Sep 17 00:00:00 2001
From: Pieter Droogendijk <pieter@binky.org.uk>
Date: Sun, 1 Jul 2012 00:27:05 +1000
Subject: [PATCH] cmd/dist: Make windows.c's fatal() print to stderr

Generating env.bat using dist env -wp > env.bat failed silently
if case of an error, because the message was redirected to env.bat.
Verbose messages still go to stdout, causing problems, but that's
a seperate change.
Made errprintf() identical to xprintf(), except for the output handle.
Yes, it's duplicate code, but most of the function is unpacking
the argument list and preparing it for WriteFile(), which has to be
done anyway.

R=golang-dev, alex.brainman
CC=golang-dev
https://golang.org/cl/6343047
---
 src/cmd/dist/windows.c | 18 +++++++++++++++++-
 1 file changed, 17 insertions(+), 1 deletion(-)

diff --git a/src/cmd/dist/windows.c b/src/cmd/dist/windows.c
index 0caee73f536..ec26f787240 100644
--- a/src/cmd/dist/windows.c
+++ b/src/cmd/dist/windows.c
@@ -121,6 +121,22 @@ errstr(void)
 	return bstr(&b);  // leak but we're dying anyway
 }
 
+static void
+errprintf(char *fmt, ...) {
+	va_list arg;
+	char *p;
+	DWORD n, w;
+
+	va_start(arg, fmt);
+	n = vsnprintf(NULL, 0, fmt, arg);
+	p = xmalloc(n+1);
+	vsnprintf(p, n+1, fmt, arg);
+	va_end(arg);
+	w = 0;
+	WriteFile(GetStdHandle(STD_ERROR_HANDLE), p, n, &w, 0);
+	xfree(p);
+}
+
 void
 xgetenv(Buf *b, char *name)
 {
@@ -709,7 +725,7 @@ fatal(char *msg, ...)
 	vsnprintf(buf1, sizeof buf1, msg, arg);
 	va_end(arg);
 
-	xprintf("go tool dist: %s\n", buf1);
+	errprintf("go tool dist: %s\n", buf1);
 	
 	bgwait();
 	ExitProcess(1);