From 94c8ff3a01d9bd1005f066a0ee3fe43c842a43b7 Mon Sep 17 00:00:00 2001
From: Markus Armbruster <armbru@redhat.com>
Date: Tue, 15 Jan 2013 14:23:37 +0100
Subject: [PATCH] w32: Make qemu_vfree() accept NULL like the POSIX
 implementation

On POSIX, qemu_vfree() accepts NULL, because it's merely wrapper
around free().  As far as I can tell, the Windows implementation
doesn't.  Breeds bugs that bite only under Windows.

Make the Windows implementation behave like the POSIX implementation.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 util/oslib-win32.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/util/oslib-win32.c b/util/oslib-win32.c
index e7e283e875..640194c0cf 100644
--- a/util/oslib-win32.c
+++ b/util/oslib-win32.c
@@ -71,7 +71,9 @@ void *qemu_vmalloc(size_t size)
 void qemu_vfree(void *ptr)
 {
     trace_qemu_vfree(ptr);
-    VirtualFree(ptr, 0, MEM_RELEASE);
+    if (ptr) {
+        VirtualFree(ptr, 0, MEM_RELEASE);
+    }
 }
 
 /* FIXME: add proper locking */