always use mktimegm


git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@3570 c046a42c-6fe2-441c-8c8c-71466251a162
diff --git a/cutils.c b/cutils.c
index 074b5ac..7836a3e 100644
--- a/cutils.c
+++ b/cutils.c
@@ -81,3 +81,17 @@
         *ptr = p;
     return 1;
 }
+
+time_t mktimegm(struct tm *tm)
+{
+    time_t t;
+    int y = tm->tm_year + 1900, m = tm->tm_mon + 1, d = tm->tm_mday;
+    if (m < 3) {
+        m += 12;
+        y--;
+    }
+    t = 86400 * (d + (153 * m - 457) / 5 + 365 * y + y / 4 - y / 100 + 
+                 y / 400 - 719469);
+    t += 3600 * tm->tm_hour + 60 * tm->tm_min + tm->tm_sec;
+    return t;
+}