From 311e23d37ace337b0c6a78959dbe8623a1ce7ed1 Mon Sep 17 00:00:00 2001
From: des <des@d4fa192b-c00b-0410-8231-f00ffab90ce4>
Date: Wed, 23 May 2007 08:14:11 +0000
Subject: [PATCH] From FreeBSD: if (flags & O_TRUNC), don't truncate the file
 until we've successfully locked it.

git-svn-id: svn+ssh://projects.linpro.no/svn/varnish/trunk@1467 d4fa192b-c00b-0410-8231-f00ffab90ce4
---
 varnish-cache/lib/libvarnish/flopen.c | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/varnish-cache/lib/libvarnish/flopen.c b/varnish-cache/lib/libvarnish/flopen.c
index 009d898a..d0c03f7c 100644
--- a/varnish-cache/lib/libvarnish/flopen.c
+++ b/varnish-cache/lib/libvarnish/flopen.c
@@ -26,7 +26,7 @@
  *
  * $Id$
  * Derived from:
- * $FreeBSD: src/lib/libutil/flopen.c,v 1.4 2007/05/10 15:01:42 des Exp $
+ * $FreeBSD: src/lib/libutil/flopen.c,v 1.5 2007/05/23 08:12:34 des Exp $
  */
 
 #include <sys/file.h>
@@ -42,7 +42,7 @@
 int
 flopen(const char *path, int flags, ...)
 {
-	int fd, operation, serrno;
+	int fd, operation, serrno, truncate;
 	struct stat sb, fsb;
 	mode_t mode;
 
@@ -63,6 +63,9 @@ flopen(const char *path, int flags, ...)
 	if (flags & O_NONBLOCK)
 		operation |= LOCK_NB;
 
+	truncate = (flags & O_TRUNC);
+	flags |= ~O_TRUNC;
+
 	for (;;) {
 		if ((fd = open(path, flags, mode)) == -1)
 			/* non-existent or no access */
@@ -92,6 +95,13 @@ flopen(const char *path, int flags, ...)
 			close(fd);
 			continue;
 		}
+		if (truncate && ftruncate(fd, 0) != 0) {
+			/* can't happen [tm] */
+			serrno = errno;
+			close(fd);
+			errno = serrno;
+			return (-1);
+		}
 		return (fd);
 	}
 }
-- 
2.39.5