Actually commit the right fix from cperciva

libpkg/fetch.c

@@ -145,7 +145,7 @@ pkg_fetch_file_to_fd(const char *url, int dest, time_t t)
 	retry = max_retry;
 
 	u = fetchParseURL(url);
-	if (t != 0 && st.mtime != 0)
+	if (t != 0)
 		u->ims_time = t;
 
 	doc = u->doc;
@@ -212,7 +212,7 @@ pkg_fetch_file_to_fd(const char *url, int dest, time_t t)
 			}
 		}
 	}
-	if (t != 0) {
+	if (t != 0 && st.mtime != 0) {
 		if (st.mtime <= t) {
 			retcode = EPKG_UPTODATE;
 			goto cleanup;