Cache Successful Result For Future Use

Per suggestion from @MarkBaker

src/PhpSpreadsheet/Shared/CodePage.php

@@ -8,7 +8,8 @@ class CodePage
 {
     public const DEFAULT_CODE_PAGE = 'CP1252';
 
-    private const PAGE_ARRAY = [
+    /** @var array */
+    private static $pageArray = [
         0 => 'CP1252', //    CodePage is not always correctly set when the xls file was saved by Apple's Numbers program
         367 => 'ASCII', //    ASCII
         437 => 'CP437', //    OEM US
@@ -70,7 +71,7 @@ class CodePage
 
     public static function validate(string $codePage): bool
     {
-        return in_array($codePage, self::PAGE_ARRAY, true);
+        return in_array($codePage, self::$pageArray, true);
     }
 
     /**
@@ -83,11 +84,13 @@ public static function validate(string $codePage): bool
      */
     public static function numberToName(int $codePage): string
     {
-        if (array_key_exists($codePage, self::PAGE_ARRAY)) {
-            $value = self::PAGE_ARRAY[$codePage];
+        if (array_key_exists($codePage, self::$pageArray)) {
+            $value = self::$pageArray[$codePage];
             if (is_array($value)) {
                 foreach ($value as $encoding) {
                     if (@iconv('UTF-8', $encoding, ' ') !== false) {
+                        self::$pageArray[$codePage] = $encoding;
+
                         return $encoding;
                     }
                 }
@@ -106,6 +109,6 @@ public static function numberToName(int $codePage): string
 
     public static function getEncodings(): array
     {
-        return self::PAGE_ARRAY;
+        return self::$pageArray;
     }
 }

tests/PhpSpreadsheetTests/Reader/Xls/XlsTest.php

@@ -4,6 +4,7 @@
 
 use PhpOffice\PhpSpreadsheet\Cell\Cell;
 use PhpOffice\PhpSpreadsheet\Reader\Xls;
+use PhpOffice\PhpSpreadsheet\Shared\CodePage;
 use PhpOffice\PhpSpreadsheetTests\Functional\AbstractFunctional;
 
 class XlsTest extends AbstractFunctional
@@ -17,6 +18,7 @@ public function testLoadXlsSample(): void
         $reader = new Xls();
         $spreadsheet = $reader->load($filename);
         self::assertEquals('Title', $spreadsheet->getSheet(0)->getCell('A1')->getValue());
+        $spreadsheet->disconnectWorksheets();
     }
 
     /**
@@ -43,6 +45,8 @@ public function testLoadXlsBug1505(): void
         self::assertEquals($row, $newrow);
         self::assertEquals($sheet->getCell('A1')->getFormattedValue(), $newsheet->getCell('A1')->getFormattedValue());
         self::assertEquals($sheet->getCell("$col$row")->getFormattedValue(), $newsheet->getCell("$col$row")->getFormattedValue());
+        $spreadsheet->disconnectWorksheets();
+        $newspreadsheet->disconnectWorksheets();
     }
 
     /**
@@ -80,6 +84,8 @@ public function testLoadXlsBug1592(): void
                 self::assertEquals($valOld, $valNew);
             }
         }
+        $spreadsheet->disconnectWorksheets();
+        $newspreadsheet->disconnectWorksheets();
     }
 
     /**
@@ -88,11 +94,31 @@ public function testLoadXlsBug1592(): void
      */
     public function testLoadMacCentralEurope(): void
     {
+        $codePages = CodePage::getEncodings();
+        self::assertIsArray($codePages[10029]);
         $filename = 'tests/data/Reader/XLS/maccentraleurope.xls';
         $reader = new Xls();
         // When no fix applied, spreadsheet fails to load on some systems
         $spreadsheet = $reader->load($filename);
         $sheet = $spreadsheet->getActiveSheet();
         self::assertSame('Ładowność', $sheet->getCell('I1')->getValue());
+        $spreadsheet->disconnectWorksheets();
+    }
+
+    /**
+     * First test changes array entry in CodePage.
+     * This test confirms new that new entry is okay.
+     */
+    public function testLoadMacCentralEurope2(): void
+    {
+        $codePages = CodePage::getEncodings();
+        self::assertIsString($codePages[10029]);
+        $filename = 'tests/data/Reader/XLS/maccentraleurope.xls';
+        $reader = new Xls();
+        // When no fix applied, spreadsheet fails to load on some systems
+        $spreadsheet = $reader->load($filename);
+        $sheet = $spreadsheet->getActiveSheet();
+        self::assertSame('Ładowność', $sheet->getCell('I1')->getValue());
+        $spreadsheet->disconnectWorksheets();
     }
 }