Don't remove the file for newly created, changed archives without survivors.

--HG--
branch : HEAD

lib/zip_close.c

diff --git a/lib/zip_close.c b/lib/zip_close.c
index 49462d8..f5dc3a6 100644
--- a/lib/zip_close.c
+++ b/lib/zip_close.c
@@ -91,7 +91,7 @@
 
     /* don't create zip files with no entries */
     if (survivors == 0) {
-	if (za->zn) {
+	if (za->zn && za->zp) {
 	    if (remove(za->zn) != 0) {
 		_zip_error_set(&za->error, ZIP_ER_REMOVE, errno);
 		return -1;