From: Gleb Natapov <gleb@redhat.com>
Date: Sun, 6 Nov 2011 16:00:22 +0000 (+0200)
Subject: qemu_timedate_diff() shouldn't modify its argument.
X-Git-Tag: qemu-xen-4.2.0~167
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=f54c556c08c57a317ad54f5d2d9ad549b931cda2;p=qemu-upstream-4.2-testing.git

qemu_timedate_diff() shouldn't modify its argument.

The caller of qemu_timedate_diff() does not expect that tm it passes to
the function will be modified, but mktime() is destructive and modifies
its argument. Pass a copy of tm to it and set tm_isdst so that mktime()
will not rely on it since its value may be outdated.

Signed-off-by: Gleb Natapov <gleb@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
---

diff --git a/vl.c b/vl.c
index 624da0fd3..641629b1c 100644
--- a/vl.c
+++ b/vl.c
@@ -460,8 +460,11 @@ int qemu_timedate_diff(struct tm *tm)
     if (rtc_date_offset == -1)
         if (rtc_utc)
             seconds = mktimegm(tm);
-        else
-            seconds = mktime(tm);
+        else {
+            struct tm tmp = *tm;
+            tmp.tm_isdst = -1; /* use timezone to figure it out */
+            seconds = mktime(&tmp);
+	}
     else
         seconds = mktimegm(tm) + rtc_date_offset;