Fix localtime handling for legacy timestamp semantics

Correct `localtime` behavior in legacy timestamp semantics when the session time zone’s current offset differs from its offset on 1970-01-01.

Author: imjalpreet

presto-main-base/src/main/java/com/facebook/presto/operator/scalar/DateTimeFunctions.java

@@ -143,7 +143,8 @@ public static long currentTime(SqlFunctionProperties properties)
     public static long localTime(SqlFunctionProperties properties)
     {
         if (properties.isLegacyTimestamp()) {
-            return UTC_CHRONOLOGY.millisOfDay().get(properties.getSessionStartTime());
+            long millis = UTC_CHRONOLOGY.millisOfDay().get(properties.getSessionStartTime());
+            return millis - valueToSessionTimeZoneOffsetDiff(properties.getSessionStartTime(), getDateTimeZone(properties.getTimeZoneKey()));
         }
         ISOChronology localChronology = getChronology(properties.getTimeZoneKey());
         return localChronology.millisOfDay().get(properties.getSessionStartTime());

presto-main-base/src/test/java/com/facebook/presto/operator/scalar/TestDateTimeFunctions.java

@@ -15,7 +15,6 @@
 package com.facebook.presto.operator.scalar;
 
 import com.facebook.presto.Session;
-import com.facebook.presto.common.type.TimeType;
 import com.facebook.presto.common.type.TimestampType;
 import org.joda.time.DateTime;
 import org.testng.annotations.Test;
@@ -45,17 +44,6 @@ public void testFormatDateCannotImplicitlyAddTimeZoneToTimestampLiteral()
                 "format_datetime for TIMESTAMP type, cannot use 'Z' nor 'z' in format, as this type does not contain TZ information");
     }
 
-    @Test
-    public void testLocalTime()
-    {
-        Session localSession = Session.builder(session)
-                .setStartTime(new DateTime(2017, 3, 1, 14, 30, 0, 0, DATE_TIME_ZONE).getMillis())
-                .build();
-        try (FunctionAssertions localAssertion = new FunctionAssertions(localSession)) {
-            localAssertion.assertFunctionString("LOCALTIME", TimeType.TIME, "14:30:00.000");
-        }
-    }
-
     @Test
     public void testLocalTimestamp()
     {

presto-main-base/src/test/java/com/facebook/presto/operator/scalar/TestDateTimeFunctionsBase.java

@@ -186,6 +186,17 @@ private static long epochDaysInZone(TimeZoneKey timeZoneKey, long instant)
         return LocalDate.from(Instant.ofEpochMilli(instant).atZone(ZoneId.of(timeZoneKey.getId()))).toEpochDay();
     }
 
+    @Test
+    public void testLocalTime()
+    {
+        Session localSession = Session.builder(session)
+                .setStartTime(new DateTime(2017, 3, 1, 14, 30, 0, 0, DATE_TIME_ZONE).getMillis())
+                .build();
+        try (FunctionAssertions localAssertion = new FunctionAssertions(localSession)) {
+            localAssertion.assertFunctionString("LOCALTIME", TimeType.TIME, "14:30:00.000");
+        }
+    }
+
     @Test
     public void testCurrentTime()
     {

presto-main-base/src/test/java/com/facebook/presto/operator/scalar/TestDateTimeFunctionsLegacy.java

@@ -15,7 +15,6 @@
 package com.facebook.presto.operator.scalar;
 
 import com.facebook.presto.Session;
-import com.facebook.presto.common.type.TimeType;
 import com.facebook.presto.common.type.TimestampType;
 import org.joda.time.DateTime;
 import org.testng.annotations.Test;
@@ -44,17 +43,6 @@ public void testFormatDateCanImplicitlyAddTimeZoneToTimestampLiteral()
         assertFunction("format_datetime(" + TIMESTAMP_LITERAL + ", 'YYYY/MM/dd HH:mm ZZZZ')", VARCHAR, "2001/08/22 03:04 " + DATE_TIME_ZONE.getID());
     }
 
-    @Test
-    public void testLocalTime()
-    {
-        Session localSession = Session.builder(session)
-                .setStartTime(new DateTime(2017, 3, 1, 14, 30, 0, 0, DATE_TIME_ZONE).getMillis())
-                .build();
-        try (FunctionAssertions localAssertion = new FunctionAssertions(localSession)) {
-            localAssertion.assertFunctionString("LOCALTIME", TimeType.TIME, "13:30:00.000");
-        }
-    }
-
     @Test
     public void testLocalTimestamp()
     {