From 9171715a880bf65bb698c6c76480d0a3fe65ae20 Mon Sep 17 00:00:00 2001
From: Marcono1234 <Marcono1234@users.noreply.github.com>
Date: Sun, 3 May 2020 00:34:08 +0200
Subject: [PATCH] Fix ISO8601UtilsTest failing on systems with UTC+X

Previously ISO8601UtilsTest.testDateFormatString() would fail on systems
where the time zone is UTC+X because getTime() returned "2018-06-24" for them.

Additionally the tests which previously changed the system locale and time
zone have been rewritten to create a UTC calendar instead. Setting locale
seems to not be necessary because ISO8601Utils.parse(...) does not do that
either.
---
 .../internal/bind/util/ISO8601UtilsTest.java  | 71 +++++++++----------
 1 file changed, 32 insertions(+), 39 deletions(-)

diff --git a/gson/src/test/java/com/google/gson/internal/bind/util/ISO8601UtilsTest.java b/gson/src/test/java/com/google/gson/internal/bind/util/ISO8601UtilsTest.java
index 10b7b5e0..1c6c69c0 100644
--- a/gson/src/test/java/com/google/gson/internal/bind/util/ISO8601UtilsTest.java
+++ b/gson/src/test/java/com/google/gson/internal/bind/util/ISO8601UtilsTest.java
@@ -15,9 +15,25 @@ public class ISO8601UtilsTest {
     @Rule
     public final ExpectedException exception = ExpectedException.none();
 
+    private static TimeZone utcTimeZone() {
+        return TimeZone.getTimeZone("UTC");
+    }
+
+    private static GregorianCalendar createUtcCalendar() {
+        TimeZone utc = utcTimeZone();
+        GregorianCalendar calendar = new GregorianCalendar(utc);
+        // Calendar was created with current time, must clear it
+        calendar.clear();
+        return calendar;
+    }
+
     @Test
     public void testDateFormatString() {
-        Date date = new GregorianCalendar(2018, Calendar.JUNE, 25).getTime();
+        GregorianCalendar calendar = new GregorianCalendar(utcTimeZone(), Locale.US);
+        // Calendar was created with current time, must clear it
+        calendar.clear();
+        calendar.set(2018, Calendar.JUNE, 25);
+        Date date = calendar.getTime();
         String dateStr = ISO8601Utils.format(date);
         String expectedDate = "2018-06-25";
         assertEquals(expectedDate, dateStr.substring(0, expectedDate.length()));
@@ -51,51 +67,28 @@ public class ISO8601UtilsTest {
 
     @Test
     public void testDateParseWithTimezone() throws ParseException {
-        TimeZone defaultTimeZone = TimeZone.getDefault();
-        TimeZone.setDefault(TimeZone.getTimeZone("UTC"));
-        Locale defaultLocale = Locale.getDefault();
-        Locale.setDefault(Locale.US);
-        try {
-            String dateStr = "2018-06-25T00:00:00-03:00";
-            Date date = ISO8601Utils.parse(dateStr, new ParsePosition(0));
-            Date expectedDate = new GregorianCalendar(2018, Calendar.JUNE, 25, 3, 0).getTime();
-            assertEquals(expectedDate, date);
-        } finally {
-            TimeZone.setDefault(defaultTimeZone);
-            Locale.setDefault(defaultLocale);
-        }
+        String dateStr = "2018-06-25T00:00:00-03:00";
+        Date date = ISO8601Utils.parse(dateStr, new ParsePosition(0));
+        GregorianCalendar calendar = createUtcCalendar();
+        calendar.set(2018, Calendar.JUNE, 25, 3, 0);
+        Date expectedDate = calendar.getTime();
+        assertEquals(expectedDate, date);
     }
 
     @Test
     public void testDateParseSpecialTimezone() throws ParseException {
-        TimeZone defaultTimeZone = TimeZone.getDefault();
-        TimeZone.setDefault(TimeZone.getTimeZone("UTC"));
-        Locale defaultLocale = Locale.getDefault();
-        Locale.setDefault(Locale.US);
-        try {
-            String dateStr = "2018-06-25T00:02:00-02:58";
-            Date date = ISO8601Utils.parse(dateStr, new ParsePosition(0));
-            Date expectedDate = new GregorianCalendar(2018, Calendar.JUNE, 25, 3, 0).getTime();
-            assertEquals(expectedDate, date);
-        } finally {
-            TimeZone.setDefault(defaultTimeZone);
-            Locale.setDefault(defaultLocale);
-        }
+        String dateStr = "2018-06-25T00:02:00-02:58";
+        Date date = ISO8601Utils.parse(dateStr, new ParsePosition(0));
+        GregorianCalendar calendar = createUtcCalendar();
+        calendar.set(2018, Calendar.JUNE, 25, 3, 0);
+        Date expectedDate = calendar.getTime();
+        assertEquals(expectedDate, date);
     }
 
     @Test
     public void testDateParseInvalidTime() throws ParseException {
-        TimeZone defaultTimeZone = TimeZone.getDefault();
-        TimeZone.setDefault(TimeZone.getTimeZone("UTC"));
-        Locale defaultLocale = Locale.getDefault();
-        Locale.setDefault(Locale.US);
-        try {
-            String dateStr = "2018-06-25T61:60:62-03:00";
-            exception.expect(ParseException.class);
-            ISO8601Utils.parse(dateStr, new ParsePosition(0));
-        } finally {
-            TimeZone.setDefault(defaultTimeZone);
-            Locale.setDefault(defaultLocale);
-        }
+        String dateStr = "2018-06-25T61:60:62-03:00";
+        exception.expect(ParseException.class);
+        ISO8601Utils.parse(dateStr, new ParsePosition(0));
     }
 }