return FALSE from strftime on negative timestamp values

they do not make sense anyway and seem to crash win2k

diff --git a/ext/standard/datetime.c b/ext/standard/datetime.c
index 30f0aa77781079158dd11119806d783a1fc9c9b8..d3da443f9b24ef9e26f1fb5b543f2ae2b26644aa 100644 (file)
--- a/ext/standard/datetime.c
+++ b/ext/standard/datetime.c
@@ -664,6 +664,9 @@ void _php_strftime(INTERNAL_FUNCTION_PARAMETERS, int gm)
        if ((*format_arg)->value.str.len==0) {
                RETURN_FALSE;
        }
+       if (timestamp < 0) {
+               RETURN_FALSE;
+       }
        format = (*format_arg)->value.str.val;
        if (gm) {
                ta = php_gmtime_r(&timestamp, &tmbuf);