Merge pull request #4159 from sylvestre/issue_3780

date: add a test for the issue 3780 to make sure we don't regress

tests/by-util/test_date.rs

@@ -109,6 +109,11 @@ fn test_date_format_full_day() {
         .stdout_matches(&re);
 }
 
+#[test]
+fn test_date_issue_3780() {
+    new_ucmd!().arg("+%Y-%m-%d %H-%M-%S%:::z").succeeds();
+}
+
 #[test]
 fn test_date_nano_seconds() {
     // %N     nanoseconds (000000000..999999999)