From 3c78cd0881e19ab3aed16a6a742ccfa9678215bc Mon Sep 17 00:00:00 2001
From: Nils Dijk <me@thanod.nl>
Date: Tue, 4 Nov 2014 07:56:05 -0600
Subject: [PATCH] Aggregations: fix rounding issues on DST switch.

Closes #8339.
---
 .../common/rounding/TimeZoneRounding.java     |  7 ++--
 .../rounding/TimeZoneRoundingTests.java       | 39 +++++++++++++++++++
 2 files changed, 42 insertions(+), 4 deletions(-)

diff --git a/src/main/java/org/elasticsearch/common/rounding/TimeZoneRounding.java b/src/main/java/org/elasticsearch/common/rounding/TimeZoneRounding.java
index 7ca00c7ec2d1f..4a07d27fc399d 100644
--- a/src/main/java/org/elasticsearch/common/rounding/TimeZoneRounding.java
+++ b/src/main/java/org/elasticsearch/common/rounding/TimeZoneRounding.java
@@ -153,14 +153,13 @@ public byte id() {
 
         @Override
         public long roundKey(long utcMillis) {
-            long time = utcMillis + preTz.getOffset(utcMillis);
-            return field.roundFloor(time);
+            long offset = preTz.getOffset(utcMillis);
+            long time = utcMillis + offset;
+            return field.roundFloor(time) - offset;
         }
 
         @Override
         public long valueForKey(long time) {
-            // now, time is still in local, move it to UTC (or the adjustLargeInterval flag is set)
-            time = time - preTz.getOffset(time);
             // now apply post Tz
             time = time + postTz.getOffset(time);
             return time;
diff --git a/src/test/java/org/elasticsearch/common/rounding/TimeZoneRoundingTests.java b/src/test/java/org/elasticsearch/common/rounding/TimeZoneRoundingTests.java
index a3d70c73a813e..e79ad1e4b1d56 100644
--- a/src/test/java/org/elasticsearch/common/rounding/TimeZoneRoundingTests.java
+++ b/src/test/java/org/elasticsearch/common/rounding/TimeZoneRoundingTests.java
@@ -83,6 +83,45 @@ public void testTimeTimeZoneRounding() {
         assertThat(tzRounding.round(utc("2009-02-03T01:01:01")), equalTo(time("2009-02-03T01:00:00", DateTimeZone.forOffsetHours(+2))));
         assertThat(tzRounding.nextRoundingValue(time("2009-02-03T01:00:00", DateTimeZone.forOffsetHours(+2))), equalTo(time("2009-02-03T02:00:00", DateTimeZone.forOffsetHours(+2))));
     }
+    
+    @Test
+    public void testTimeTimeZoneRoundingDST() {
+        Rounding tzRounding;
+        // testing savings to non savings switch 
+        tzRounding = TimeZoneRounding.builder(DateTimeUnit.HOUR_OF_DAY).preZone(DateTimeZone.forID("UTC")).build();
+        assertThat(tzRounding.round(time("2014-10-26T01:01:01", DateTimeZone.forID("CET"))), equalTo(time("2014-10-26T01:00:00", DateTimeZone.forID("CET"))));
+        
+        tzRounding = TimeZoneRounding.builder(DateTimeUnit.HOUR_OF_DAY).preZone(DateTimeZone.forID("CET")).build();
+        assertThat(tzRounding.round(time("2014-10-26T01:01:01", DateTimeZone.forID("CET"))), equalTo(time("2014-10-26T01:00:00", DateTimeZone.forID("CET"))));
+        
+        // testing non savings to savings switch
+        tzRounding = TimeZoneRounding.builder(DateTimeUnit.HOUR_OF_DAY).preZone(DateTimeZone.forID("UTC")).build();
+        assertThat(tzRounding.round(time("2014-03-30T01:01:01", DateTimeZone.forID("CET"))), equalTo(time("2014-03-30T01:00:00", DateTimeZone.forID("CET"))));
+        
+        tzRounding = TimeZoneRounding.builder(DateTimeUnit.HOUR_OF_DAY).preZone(DateTimeZone.forID("CET")).build();
+        assertThat(tzRounding.round(time("2014-03-30T01:01:01", DateTimeZone.forID("CET"))), equalTo(time("2014-03-30T01:00:00", DateTimeZone.forID("CET"))));
+        
+        // testing non savings to savings switch (America/Chicago)
+        tzRounding = TimeZoneRounding.builder(DateTimeUnit.HOUR_OF_DAY).preZone(DateTimeZone.forID("UTC")).build();
+        assertThat(tzRounding.round(time("2014-03-09T03:01:01", DateTimeZone.forID("America/Chicago"))), equalTo(time("2014-03-09T03:00:00", DateTimeZone.forID("America/Chicago"))));
+        
+        tzRounding = TimeZoneRounding.builder(DateTimeUnit.HOUR_OF_DAY).preZone(DateTimeZone.forID("America/Chicago")).build();
+        assertThat(tzRounding.round(time("2014-03-09T03:01:01", DateTimeZone.forID("America/Chicago"))), equalTo(time("2014-03-09T03:00:00", DateTimeZone.forID("America/Chicago"))));
+        
+        // testing savings to non savings switch 2013 (America/Chicago)
+        tzRounding = TimeZoneRounding.builder(DateTimeUnit.HOUR_OF_DAY).preZone(DateTimeZone.forID("UTC")).build();
+        assertThat(tzRounding.round(time("2013-11-03T06:01:01", DateTimeZone.forID("America/Chicago"))), equalTo(time("2013-11-03T06:00:00", DateTimeZone.forID("America/Chicago"))));
+        
+        tzRounding = TimeZoneRounding.builder(DateTimeUnit.HOUR_OF_DAY).preZone(DateTimeZone.forID("America/Chicago")).build();
+        assertThat(tzRounding.round(time("2013-11-03T06:01:01", DateTimeZone.forID("America/Chicago"))), equalTo(time("2013-11-03T06:00:00", DateTimeZone.forID("America/Chicago"))));
+        
+        // testing savings to non savings switch 2014 (America/Chicago)
+        tzRounding = TimeZoneRounding.builder(DateTimeUnit.HOUR_OF_DAY).preZone(DateTimeZone.forID("UTC")).build();
+        assertThat(tzRounding.round(time("2014-11-02T06:01:01", DateTimeZone.forID("America/Chicago"))), equalTo(time("2014-11-02T06:00:00", DateTimeZone.forID("America/Chicago"))));
+        
+        tzRounding = TimeZoneRounding.builder(DateTimeUnit.HOUR_OF_DAY).preZone(DateTimeZone.forID("America/Chicago")).build();
+        assertThat(tzRounding.round(time("2014-11-02T06:01:01", DateTimeZone.forID("America/Chicago"))), equalTo(time("2014-11-02T06:00:00", DateTimeZone.forID("America/Chicago"))));
+    }
 
     private long utc(String time) {
         return time(time, DateTimeZone.UTC);