set return_len to 0 when returning empty string and fix segfault

diff --git a/ext/date/php_date.c b/ext/date/php_date.c
index eab0a31f3a8bb9816db780bb517c411cc472d742..df07b8adfda0a0e7887bbb0d98332232c750fe28 100644 (file)
--- a/ext/date/php_date.c
+++ b/ext/date/php_date.c
@@ -1082,6 +1082,7 @@ static char *date_format(char *format, int format_len, int *return_len, timelib_
        int                  rfc_colon;
 
        if (!format_len) {
+               *return_len = 0;
                if (UG(unicode)) {
                        return (char*)eustrdup(EMPTY_STR);
                } else {