From 8c4c11346b4fcc8df1c00a1e1290813f9e623376 Mon Sep 17 00:00:00 2001
From: Adrien Crivelli <adrien.crivelli@gmail.com>
Date: Sun, 2 Oct 2016 14:46:11 +0900
Subject: [PATCH] Fix unit tests for DATEDIF()

Leap years where not properly taken into consideration
---
 src/PhpSpreadsheet/Calculation/DateTime.php   | 19 +++++++++---
 .../Calculation/DateTimeTest.php              |  3 --
 tests/data/Calculation/DateTime/DATEDIF.php   | 30 +++++++++++++++++++
 3 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/src/PhpSpreadsheet/Calculation/DateTime.php b/src/PhpSpreadsheet/Calculation/DateTime.php
index a748c4eb..5d9614a1 100644
--- a/src/PhpSpreadsheet/Calculation/DateTime.php
+++ b/src/PhpSpreadsheet/Calculation/DateTime.php
@@ -729,13 +729,24 @@ class DateTime
             case 'YD':
                 $retVal = intval($difference);
                 if ($endYears > $startYears) {
-                    while ($endYears > $startYears) {
+                    $isLeapStartYear = $PHPStartDateObject->format('L');
+                    $wasLeapEndYear = $PHPEndDateObject->format('L');
+
+                    // Adjust end year to be as close as possible as start year
+                    while ($PHPEndDateObject >= $PHPStartDateObject) {
                         $PHPEndDateObject->modify('-1 year');
                         $endYears = $PHPEndDateObject->format('Y');
                     }
-                    $retVal = $PHPEndDateObject->format('z') - $PHPStartDateObject->format('z');
-                    if ($retVal < 0) {
-                        $retVal += 365;
+                    $PHPEndDateObject->modify('+1 year');
+
+                    // Get the result
+                    $retVal =  $PHPEndDateObject->diff($PHPStartDateObject)->days;
+
+                    // Adjust for leap years cases
+                    $isLeapEndYear = $PHPEndDateObject->format('L');
+                    $limit = new \DateTime($PHPEndDateObject->format('Y-02-29'));
+                    if (!$isLeapStartYear && !$wasLeapEndYear && $isLeapEndYear && $PHPEndDateObject >= $limit ) {
+                        $retVal--;
                     }
                 }
                 break;
diff --git a/tests/PhpSpreadsheetTests/Calculation/DateTimeTest.php b/tests/PhpSpreadsheetTests/Calculation/DateTimeTest.php
index bc25d58d..6abd435c 100644
--- a/tests/PhpSpreadsheetTests/Calculation/DateTimeTest.php
+++ b/tests/PhpSpreadsheetTests/Calculation/DateTimeTest.php
@@ -416,12 +416,9 @@ class DateTimeTest extends \PHPUnit_Framework_TestCase
 
     /**
      * @dataProvider providerDATEDIF
-     * @group fail19
      */
     public function testDATEDIF()
     {
-        $this->markTestIncomplete('TODO: This test should be fixed');
-
         $args = func_get_args();
         $expectedResult = array_pop($args);
         $result = call_user_func_array([DateTime::class, 'DATEDIF'], $args);
diff --git a/tests/data/Calculation/DateTime/DATEDIF.php b/tests/data/Calculation/DateTime/DATEDIF.php
index 106385fc..e8776c0f 100644
--- a/tests/data/Calculation/DateTime/DATEDIF.php
+++ b/tests/data/Calculation/DateTime/DATEDIF.php
@@ -1,6 +1,36 @@
 <?php
 
 return [
+    [
+        '2016-01-01',
+        '2016-12-31',
+        'YD',
+        365
+    ],
+    [
+        '2015-01-01',
+        '2015-12-31',
+        'YD',
+        364
+    ],
+    [
+        '2015-01-01',
+        '2016-12-31',
+        'YD',
+        364
+    ],
+    [
+        '2016-01-01',
+        '2017-12-31',
+        'YD',
+        365
+    ],
+    [
+        '2017-01-01',
+        '2018-12-31',
+        'YD',
+        364
+    ],
     [
         'ABC',
         '2007-1-10',