From 56763e88477a24785d528cb64d4341b45675c2c1 Mon Sep 17 00:00:00 2001
From: "A.R. Baart" <rbaart@gmail.com>
Date: Mon, 21 Mar 2022 16:35:21 +0100
Subject: [PATCH] Fix issue #658 duration_round by zero panics

---
 src/round.rs | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/round.rs b/src/round.rs
index b357d916c0..4b1d1dae7f 100644
--- a/src/round.rs
+++ b/src/round.rs
@@ -185,6 +185,9 @@ where
         if span > stamp.abs() {
             return Err(RoundingError::DurationExceedsTimestamp);
         }
+        if span == 0 {
+            return Ok(original)
+        }
         let delta_down = stamp % span;
         if delta_down == 0 {
             Ok(original)
@@ -394,6 +397,11 @@ mod tests {
     fn test_duration_round() {
         let dt = Utc.ymd(2016, 12, 31).and_hms_nano(23, 59, 59, 175_500_000);
 
+        assert_eq!(
+            dt.duration_round(Duration::zero()).unwrap().to_string(),
+            "2016-12-31 23:59:59.175500 UTC"
+        );
+
         assert_eq!(
             dt.duration_round(Duration::milliseconds(10)).unwrap().to_string(),
             "2016-12-31 23:59:59.180 UTC"
@@ -456,6 +464,11 @@ mod tests {
     fn test_duration_round_naive() {
         let dt = Utc.ymd(2016, 12, 31).and_hms_nano(23, 59, 59, 175_500_000).naive_utc();
 
+        assert_eq!(
+            dt.duration_round(Duration::zero()).unwrap().to_string(),
+            "2016-12-31 23:59:59.175500"
+        );
+
         assert_eq!(
             dt.duration_round(Duration::milliseconds(10)).unwrap().to_string(),
             "2016-12-31 23:59:59.180"