Fix Two 32-bit Timestamp Problems, and Minor getFormattedValue Bug (#1891)

I ran the test suite using 32-bit PHP. There were 2 places where changes
were needed due to 32-bit timestamps.

Reader\\Xml.php was using strtotime as an intermediate step in converting
a string timestamp to an Excel timestamp. The XML file type stores pure timestamps
(i.e. no date portion) as, e.g., 1899-12-31T02:30:00.000, and that value
causes an error using strtotime on a 32-bit system. However, it is sufficient
to use that value in a DateTime constructor, and that will work for 32- and 64-bit.

There was no test for that particular cell, so I added one to the XML read test.
And that's when I discovered the getFormattedValue bug. The cell's format
is `hh":"mm":"ss`. The quotes around the colons are disrupting the formatting.
PhpSpreadsheet formats the cell by converting the Excel format
to a Php Date format, in this case `H\:m\:s`.
That's a problem,
since Excel thinks 'm' means *minutes*, but PHP thinks it means *months*.
This is not a problem when the colon is not quoted; there are ample tests for that.
I added my best guess as to how to recognize this situation,
changing `\:m` to `:i`. The XML read test
now succeeds, and no other tests were broken by this change.

Test Shared\\DateTest had one test where the expected result of converting to a
Unix timestamp exceeds 2**32. Since a Unix timestamp is strictly an int,
that test fails on a 32-bit system. In the discussion regarding recently merged
PR #1870, it was felt that the user base might still be using the functions
that convert to and from a timestamp. So, we should not drop this test, but,
since it cannot succeed on a 32-bit system, I changed it to be skipped
whenever the expected result exceeded PHP_INT_MAX. There are 3 "toTimestamp"
functions within that test. Only one of these had been affected, but I thought
it was a good idea to add additional tests to the others to demonstrate this
condition.

In the course of testing, I also discovered some 32-bit problems with
bitwise and base-conversion functions. I am preparing separate PRs to
deal with those.

src/PhpSpreadsheet/Reader/Xml.php

@@ -2,6 +2,8 @@
 
 namespace PhpOffice\PhpSpreadsheet\Reader;
 
+use DateTime;
+use DateTimeZone;
 use PhpOffice\PhpSpreadsheet\Cell\AddressHelper;
 use PhpOffice\PhpSpreadsheet\Cell\Coordinate;
 use PhpOffice\PhpSpreadsheet\Cell\DataType;
@@ -557,7 +559,8 @@ class Xml extends BaseReader
                                         break;
                                     case 'DateTime':
                                         $type = DataType::TYPE_NUMERIC;
-                                        $cellValue = Date::PHPToExcel(strtotime($cellValue . ' UTC'));
+                                        $dateTime = new DateTime($cellValue, new DateTimeZone('UTC'));
+                                        $cellValue = Date::PHPToExcel($dateTime);
 
                                         break;
                                     case 'Error':

src/PhpSpreadsheet/Style/NumberFormat.php

@@ -502,6 +502,10 @@ class NumberFormat extends Supervisor
         $format = preg_replace_callback('/"(.*)"/U', ['self', 'escapeQuotesCallback'], $format);
 
         $dateObj = Date::excelToDateTimeObject($value);
+        // If the colon preceding minute had been quoted, as happens in
+        // Excel 2003 XML formats, m will not have been changed to i above.
+        // Change it now.
+        $format = \preg_replace('/\\\\:m/', ':i', $format);
         $value = $dateObj->format($format);
     }
 

tests/PhpSpreadsheetTests/Reader/Xml/XmlLoadTest.php

@@ -36,6 +36,10 @@ class XmlLoadTest extends TestCase
         self::assertEquals('# ?0/??0', $sheet->getCell('A11')->getStyle()->getNumberFormat()->getFormatCode());
         // Same pattern, same value, different display in Gnumeric vs Excel
         //self::assertEquals('1 1/2', $sheet->getCell('A11')->getFormattedValue());
+        self::assertEquals('hh":"mm":"ss', $sheet->getCell('A13')->getStyle()->getNumberFormat()->getFormatCode());
+        self::assertEquals('02:30:00', $sheet->getCell('A13')->getFormattedValue());
+        self::assertEquals('d/m/yy hh":"mm', $sheet->getCell('A15')->getStyle()->getNumberFormat()->getFormatCode());
+        self::assertEquals('19/12/60 01:30', $sheet->getCell('A15')->getFormattedValue());
 
         self::assertEquals('=B1+C1', $sheet->getCell('H1')->getValue());
         self::assertEquals('=E2&F2', $sheet->getCell('J2')->getValue());

tests/PhpSpreadsheetTests/Shared/DateTest.php

@@ -8,16 +8,20 @@ use PHPUnit\Framework\TestCase;
 
 class DateTest extends TestCase
 {
+    private $excelCalendar;
+
     private $dttimezone;
 
     protected function setUp(): void
     {
         $this->dttimezone = Date::getDefaultTimeZone();
+        $this->excelCalendar = Date::getExcelCalendar();
     }
 
     protected function tearDown(): void
     {
         Date::setDefaultTimeZone($this->dttimezone);
+        Date::setExcelCalendar($this->excelCalendar);
     }
 
     public function testSetExcelCalendar(): void
@@ -47,6 +51,9 @@ class DateTest extends TestCase
      */
     public function testDateTimeExcelToTimestamp1900($expectedResult, ...$args): void
     {
+        if (is_numeric($expectedResult) && ($expectedResult > PHP_INT_MAX || $expectedResult < PHP_INT_MIN)) {
+            self::markTestSkipped('Test invalid on 32-bit system.');
+        }
         Date::setExcelCalendar(Date::CALENDAR_WINDOWS_1900);
 
         $result = Date::excelToTimestamp(...$args);
@@ -119,6 +126,9 @@ class DateTest extends TestCase
      */
     public function testDateTimeExcelToTimestamp1904($expectedResult, ...$args): void
     {
+        if (is_numeric($expectedResult) && ($expectedResult > PHP_INT_MAX || $expectedResult < PHP_INT_MIN)) {
+            self::markTestSkipped('Test invalid on 32-bit system.');
+        }
         Date::setExcelCalendar(Date::CALENDAR_MAC_1904);
 
         $result = Date::excelToTimestamp(...$args);
@@ -171,6 +181,9 @@ class DateTest extends TestCase
      */
     public function testDateTimeExcelToTimestamp1900Timezone($expectedResult, ...$args): void
     {
+        if (is_numeric($expectedResult) && ($expectedResult > PHP_INT_MAX || $expectedResult < PHP_INT_MIN)) {
+            self::markTestSkipped('Test invalid on 32-bit system.');
+        }
         Date::setExcelCalendar(Date::CALENDAR_WINDOWS_1900);
 
         $result = Date::excelToTimestamp(...$args);

tests/data/Shared/Date/ExcelToTimestamp1900.php

@@ -72,4 +72,11 @@ return [
         10666,
         0.12345,
     ],
+    // 29-Apr-2038 00:00:00 beyond PHP 32-bit Latest Date
+    [
+        2156112000,
+        50524,
+    ],
+    [-2147483648, -2147483648 / 86400], // Okay on 64- and 32-bit systems
+    [-2147483649, -2147483649 / 86400], // Skipped test on 32-bit
 ];

tests/data/Shared/Date/ExcelToTimestamp1904.php

@@ -42,4 +42,9 @@ return [
         gmmktime(13, 02, 13, 1, 1, 1904), // 32-bit safe - no Y2038 problem
         0.54321,
     ],
+    // 29-Apr-2038 00:00:00 beyond PHP 32-bit Latest Date
+    [
+        2156112000,
+        49062,
+    ],
 ];