Ignore Fractional Part of Drawing Shadow Alpha

Fix #4415. We store the rarely-used property Drawing/Shadow/Alpha as an integer representing the percentage. Excel also stores it as an integer, but multiplies it by 1,000, so we divide by 1,000 when we read this value. This can, and in the case of the issue at hand does, leave a fractional portion. Php has deprecated passing a float with a fractional portion to an int argument, so the reporter saw a deprecation message. This is easily fixed.

src/PhpSpreadsheet/Reader/Xlsx.php

@@ -1492,7 +1492,13 @@ class Xlsx extends BaseReader
                                                         $shadow->setAlignment(self::getArrayItemString(self::getAttributes($outerShdw), 'algn'));
                                                         $clr = $outerShdw->srgbClr ?? $outerShdw->prstClr;
                                                         $shadow->getColor()->setRGB(self::getArrayItemString(self::getAttributes($clr), 'val'));
-                                                        $shadow->setAlpha(self::getArrayItem(self::getAttributes($clr->alpha), 'val') / 1000); // @phpstan-ignore-line
+                                                        if ($clr->alpha) {
+                                                            $alpha = StringHelper::convertToString(self::getArrayItem(self::getAttributes($clr->alpha), 'val'));
+                                                            if (is_numeric($alpha)) {
+                                                                $alpha = (int) ($alpha / 1000);
+                                                                $shadow->setAlpha($alpha);
+                                                            }
+                                                        }
                                                     }
 
                                                     $this->readHyperLinkDrawing($objDrawing, $oneCellAnchor, $hyperlinks);
@@ -1597,7 +1603,13 @@ class Xlsx extends BaseReader
                                                         $shadow->setAlignment(self::getArrayItemString(self::getAttributes($outerShdw), 'algn'));
                                                         $clr = $outerShdw->srgbClr ?? $outerShdw->prstClr;
                                                         $shadow->getColor()->setRGB(self::getArrayItemString(self::getAttributes($clr), 'val'));
-                                                        $shadow->setAlpha(self::getArrayItem(self::getAttributes($clr->alpha), 'val') / 1000); // @phpstan-ignore-line
+                                                        if ($clr->alpha) {
+                                                            $alpha = StringHelper::convertToString(self::getArrayItem(self::getAttributes($clr->alpha), 'val'));
+                                                            if (is_numeric($alpha)) {
+                                                                $alpha = (int) ($alpha / 1000);
+                                                                $shadow->setAlpha($alpha);
+                                                            }
+                                                        }
                                                     }
 
                                                     $this->readHyperLinkDrawing($objDrawing, $twoCellAnchor, $hyperlinks);

tests/PhpSpreadsheetTests/Reader/Xlsx/Issue4415Test.php

@@ -0,0 +1,47 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpOffice\PhpSpreadsheetTests\Reader\Xlsx;
+
+use PhpOffice\PhpSpreadsheet\Reader\Xlsx as XlsxReader;
+use PHPUnit\Framework\TestCase;
+
+class Issue4415Test extends TestCase
+{
+    private static string $file = 'tests/data/Reader/XLSX/issue.4415.xlsx';
+
+    public function testPreliminaries(): void
+    {
+        $file = 'zip://';
+        $file .= self::$file;
+        $file .= '#xl/drawings/drawing1.xml';
+        $data = file_get_contents($file) ?: '';
+        $expected = '<a:alpha val="72600"/>';
+        self::assertStringContainsString($expected, $data);
+        $expected = '<a:alpha val="90100"/>';
+        self::assertStringContainsString($expected, $data);
+        self::assertSame(2, substr_count($data, '<a:alpha '), 'number of drawings with alpha');
+        self::assertSame(2, substr_count($data, '<xdr:oneCellAnchor>'), 'first 2 drawings');
+        self::assertSame(1, substr_count($data, '<xdr:twoCellAnchor>'), 'third drawings');
+    }
+
+    public function testFractionalAlpha(): void
+    {
+        $file = self::$file;
+        $reader = new XlsxReader();
+        $spreadsheet = $reader->load($file);
+        $sheet = $spreadsheet->getActiveSheet();
+        $drawings = $sheet->getDrawingCollection();
+        self::assertCount(3, $drawings);
+        self::assertNotNull($drawings[0]);
+        self::assertNotNull($drawings[1]);
+        self::assertNotNull($drawings[2]);
+        self::assertSame(50, $drawings[0]->getShadow()->getAlpha());
+        self::assertSame(72, $drawings[1]->getShadow()->getAlpha());
+        self::assertSame('', $drawings[1]->getCoordinates2(), 'one cell anchor');
+        self::assertSame(90, $drawings[2]->getShadow()->getAlpha());
+        self::assertNotEquals('', $drawings[2]->getCoordinates2(), 'two cell anchor');
+        $spreadsheet->disconnectWorksheets();
+    }
+}