From e7552dcac88ff2a29adea20e9d7352582a0b497b Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Richard=20K=C3=B6rber?= <github@shredzone.org>
Date: Thu, 4 Jul 2019 00:51:02 +0200
Subject: [PATCH] Fix possible error in alwaysUp/alwaysDown

---
 .../org/shredzone/commons/suncalc/SunTimes.java   | 15 +++++++++------
 .../org/shredzone/commons/suncalc/Locations.java  |  6 ++++++
 .../shredzone/commons/suncalc/SunTimesTest.java   |  7 +++++++
 3 files changed, 22 insertions(+), 6 deletions(-)

diff --git a/src/main/java/org/shredzone/commons/suncalc/SunTimes.java b/src/main/java/org/shredzone/commons/suncalc/SunTimes.java
index cc47bbb..437a2da 100644
--- a/src/main/java/org/shredzone/commons/suncalc/SunTimes.java
+++ b/src/main/java/org/shredzone/commons/suncalc/SunTimes.java
@@ -274,9 +274,9 @@ public SunTimes execute() {
             Double set = null;
             Double noon = null;
             Double nadir = null;
+            boolean alwaysUp = true;
+            boolean alwaysDown = true;
             double ye;
-            double noonYe = 0.0;
-            double nadirYe = 0.0;
 
             double y_minus = correctedSunHeight(jd);
 
@@ -308,15 +308,18 @@ public SunTimes execute() {
                 }
 
                 if (hour < 24) {
+                    if (y_0 > 0.0) {
+                        alwaysDown = false;
+                    } else {
+                        alwaysUp = false;
+                    }
                     double xeAbs = Math.abs(qi.getXe());
                     if (xeAbs <= 1.0) {
                         double xeHour = qi.getXe() + hour;
                         if (qi.isMaximum()) {
                             noon = xeHour;
-                            noonYe = ye;
                         } else {
                             nadir = xeHour;
-                            nadirYe = ye;
                         }
                     }
                 }
@@ -333,8 +336,8 @@ public SunTimes execute() {
                     set != null ? jd.atHour(set).getDateTruncated(getTruncatedTo()) : null,
                     noon != null ? jd.atHour(noon).getDateTruncated(getTruncatedTo()) : null,
                     nadir != null ? jd.atHour(nadir).getDateTruncated(getTruncatedTo()) : null,
-                    nadir == null || nadirYe > 0.0,
-                    noon == null || noonYe < 0.0
+                    alwaysUp,
+                    alwaysDown
                 );
         }
 
diff --git a/src/test/java/org/shredzone/commons/suncalc/Locations.java b/src/test/java/org/shredzone/commons/suncalc/Locations.java
index 6c6dcc5..02b73c9 100644
--- a/src/test/java/org/shredzone/commons/suncalc/Locations.java
+++ b/src/test/java/org/shredzone/commons/suncalc/Locations.java
@@ -60,4 +60,10 @@ public final class Locations {
     public static final double[] MARTINIQUE = new double[] { 14.640725, -61.0112 };
     public static final TimeZone MARTINIQUE_TZ = TimeZone.getTimeZone("America/Martinique");
 
+    /**
+     * Sydney. To test a fix for issue #14.
+     */
+    public static final double[] SYDNEY = new double[] { -33.744272, 151.231291 };
+    public static final TimeZone SYDNEY_TZ = TimeZone.getTimeZone("Australia/Sydney");
+
 }
diff --git a/src/test/java/org/shredzone/commons/suncalc/SunTimesTest.java b/src/test/java/org/shredzone/commons/suncalc/SunTimesTest.java
index 5288ac6..bf75b09 100644
--- a/src/test/java/org/shredzone/commons/suncalc/SunTimesTest.java
+++ b/src/test/java/org/shredzone/commons/suncalc/SunTimesTest.java
@@ -138,6 +138,13 @@ public void testMartinique() {
         assertTimes(t1, "2019-07-01T09:38:35Z", "2019-07-01T22:37:23Z", "2019-07-01T16:06:08Z");
     }
 
+    @Test
+    public void testSydney() {
+        SunTimes t1 = SunTimes.compute().at(SYDNEY).on(2019, 7, 3).timezone(SYDNEY_TZ)
+                .truncatedTo(Unit.SECONDS).fullCycle().execute();
+        assertTimes(t1, "2019-07-02T21:00:35Z", "2019-07-03T06:58:02Z", "2019-07-03T01:59:18Z");
+    }
+
     @Test
     public void testSequence() {
         long acceptableError = 62 * 1000L;