Xlsx Reader Accept Palette of Fewer than 64 Colors (#3096)

Fix #3093. PR #2595 added the ability for Xlsx Reader to accept a custom color palette. With no examples other than the one at hand, which included a full complement of 64 colors, that PR required 64 colors in the palette. It turns out that Mac Numbers exports to Excel with a palette with less than 64 colors. So, with an example of that at hand, relax the original restriction and accept a palette of any size.

src/PhpSpreadsheet/Reader/Xlsx.php

@@ -2162,6 +2162,6 @@ class Xlsx extends BaseReader
             }
         }
 
-        return (count($array) === 64) ? $array : [];
+        return $array;
     }
 }

src/PhpSpreadsheet/Reader/Xlsx/Styles.php

@@ -365,11 +365,12 @@ class Styles extends BaseParserClass
             return (string) $attr['rgb'];
         }
         if (isset($attr['indexed'])) {
-            if (empty($this->workbookPalette)) {
+            $indexedColor = (int) $attr['indexed'];
-                return Color::indexedColor((int) ($attr['indexed'] - 7), $background)->getARGB() ?? '';
+            if ($indexedColor >= count($this->workbookPalette)) {
+                return Color::indexedColor($indexedColor - 7, $background)->getARGB() ?? '';
             }
 
-            return Color::indexedColor((int) ($attr['indexed']), $background, $this->workbookPalette)->getARGB() ?? '';
+            return Color::indexedColor($indexedColor, $background, $this->workbookPalette)->getARGB() ?? '';
         }
         if (isset($attr['theme'])) {
             if ($this->theme !== null) {

tests/PhpSpreadsheetTests/Reader/Xlsx/Issue2490Test.php

@@ -12,6 +12,11 @@ class Issue2490Test extends TestCase
      */
     private static $testbook = 'tests/data/Reader/XLSX/issue.2490.xlsx';
 
+    /**
+     * @var string
+     */
+    private static $testbook3093 = 'tests/data/Reader/XLSX/issue.3093.xlsx';
+
     public function testPreliminaries(): void
     {
         $file = 'zip://';
@@ -23,6 +28,7 @@ class Issue2490Test extends TestCase
             self::fail('Unable to read file');
         } else {
             self::assertStringContainsString('<colors><indexedColors><rgbColor rgb="00000000"/>', $data);
+            self::assertSame(64, substr_count($data, '<rgbColor'));
         }
     }
 
@@ -38,4 +44,34 @@ class Issue2490Test extends TestCase
         self::assertSame('00F0F0F0', $sheet->getCell('B1')->getStyle()->getFill()->getStartColor()->getArgb());
         $spreadsheet->disconnectWorksheets();
     }
+
+    public function testPreliminaries3093(): void
+    {
+        $file = 'zip://';
+        $file .= self::$testbook3093;
+        $file .= '#xl/styles.xml';
+        $data = file_get_contents($file);
+        // confirm that file contains expected color index tag
+        if ($data === false) {
+            self::fail('Unable to read file');
+        } else {
+            self::assertStringContainsString('<colors><indexedColors><rgbColor rgb="ff000000"/>', $data);
+            self::assertSame(15, substr_count($data, '<rgbColor'));
+        }
+    }
+
+    public function testIssue3093(): void
+    {
+        // Same as above, except with fewer than 64 entries.
+        // (And with colors in lowercase hex and alpha set to ff.)
+        $filename = self::$testbook3093;
+        $reader = IOFactory::createReader('Xlsx');
+        $spreadsheet = $reader->load($filename);
+        $sheet = $spreadsheet->getActiveSheet();
+        self::assertSame('ffc0c0c0', $sheet->getCell('B2')->getStyle()->getFill()->getStartColor()->getArgb());
+        self::assertSame('ffffff00', $sheet->getCell('D2')->getStyle()->getFill()->getStartColor()->getArgb());
+        self::assertSame('ffdfa7a6', $sheet->getCell('F2')->getStyle()->getFill()->getStartColor()->getArgb());
+        self::assertSame('ff7ba0cd', $sheet->getCell('H2')->getStyle()->getFill()->getStartColor()->getArgb());
+        $spreadsheet->disconnectWorksheets();
+    }
 }