Ods Reader Allow Omission of Some Page Settings Tags

Fix #4099. Ods Reader was expecting there to always be `header-style` and `footer-style` tags when `page-layout` tag is present, but these need not exist. It seemed like there might be other exposures along this line in `readPageSettingStyles`; rather than waiting for a problem report to show up for each, the code is updated to use `->item(0)` in place of `[0]` when appropriate, and make use of the nullsafe `?->` operator introduced with Php8.

Author: oleibman

src/PhpSpreadsheet/Reader/Ods/PageSettings.php

@@ -55,22 +55,22 @@ private function readPageSettingStyles(DOMDocument $styleDom): void
 
         foreach ($styles as $styleSet) {
             $styleName = $styleSet->getAttributeNS($this->stylesNs, 'name');
-            $pageLayoutProperties = $styleSet->getElementsByTagNameNS($this->stylesNs, 'page-layout-properties')[0];
-            $styleOrientation = $pageLayoutProperties->getAttributeNS($this->stylesNs, 'print-orientation');
-            $styleScale = $pageLayoutProperties->getAttributeNS($this->stylesNs, 'scale-to');
-            $stylePrintOrder = $pageLayoutProperties->getAttributeNS($this->stylesNs, 'print-page-order');
-            $centered = $pageLayoutProperties->getAttributeNS($this->stylesNs, 'table-centering');
-
-            $marginLeft = $pageLayoutProperties->getAttributeNS($this->stylesFo, 'margin-left');
-            $marginRight = $pageLayoutProperties->getAttributeNS($this->stylesFo, 'margin-right');
-            $marginTop = $pageLayoutProperties->getAttributeNS($this->stylesFo, 'margin-top');
-            $marginBottom = $pageLayoutProperties->getAttributeNS($this->stylesFo, 'margin-bottom');
-            $header = $styleSet->getElementsByTagNameNS($this->stylesNs, 'header-style')[0];
-            $headerProperties = $header->getElementsByTagNameNS($this->stylesNs, 'header-footer-properties')[0];
-            $marginHeader = isset($headerProperties) ? $headerProperties->getAttributeNS($this->stylesFo, 'min-height') : null;
-            $footer = $styleSet->getElementsByTagNameNS($this->stylesNs, 'footer-style')[0];
-            $footerProperties = $footer->getElementsByTagNameNS($this->stylesNs, 'header-footer-properties')[0];
-            $marginFooter = isset($footerProperties) ? $footerProperties->getAttributeNS($this->stylesFo, 'min-height') : null;
+            $pageLayoutProperties = $styleSet->getElementsByTagNameNS($this->stylesNs, 'page-layout-properties')->item(0);
+            $styleOrientation = $pageLayoutProperties?->getAttributeNS($this->stylesNs, 'print-orientation');
+            $styleScale = $pageLayoutProperties?->getAttributeNS($this->stylesNs, 'scale-to');
+            $stylePrintOrder = $pageLayoutProperties?->getAttributeNS($this->stylesNs, 'print-page-order');
+            $centered = $pageLayoutProperties?->getAttributeNS($this->stylesNs, 'table-centering');
+
+            $marginLeft = $pageLayoutProperties?->getAttributeNS($this->stylesFo, 'margin-left');
+            $marginRight = $pageLayoutProperties?->getAttributeNS($this->stylesFo, 'margin-right');
+            $marginTop = $pageLayoutProperties?->getAttributeNS($this->stylesFo, 'margin-top');
+            $marginBottom = $pageLayoutProperties?->getAttributeNS($this->stylesFo, 'margin-bottom');
+            $header = $styleSet->getElementsByTagNameNS($this->stylesNs, 'header-style')->item(0);
+            $headerProperties = $header?->getElementsByTagNameNS($this->stylesNs, 'header-footer-properties')?->item(0);
+            $marginHeader = $headerProperties?->getAttributeNS($this->stylesFo, 'min-height');
+            $footer = $styleSet->getElementsByTagNameNS($this->stylesNs, 'footer-style')->item(0);
+            $footerProperties = $footer?->getElementsByTagNameNS($this->stylesNs, 'header-footer-properties')?->item(0);
+            $marginFooter = $footerProperties?->getAttributeNS($this->stylesFo, 'min-height');
 
             $this->pageLayoutStyles[$styleName] = (object) [
                 'orientation' => $styleOrientation ?: PageSetup::ORIENTATION_DEFAULT,

tests/PhpSpreadsheetTests/Reader/Ods/Issue4099Test.php

@@ -0,0 +1,28 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpOffice\PhpSpreadsheetTests\Reader\Ods;
+
+use PhpOffice\PhpSpreadsheet\Reader\Ods as OdsReader;
+use PHPUnit\Framework\TestCase;
+
+class Issue4099Test extends TestCase
+{
+    private string $file = 'tests/data/Reader/Ods/issue.4099.ods';
+
+    public function testNoHeaderFooterStyle(): void
+    {
+        // header-style and footer-style are missing in styles.xml
+        $zipFile = 'zip://' . $this->file . '#styles.xml';
+        $contents = (string) file_get_contents($zipFile);
+        self::assertStringContainsString('page-layout ', $contents);
+        self::assertStringNotContainsString('header-style', $contents);
+        self::assertStringNotContainsString('footer-style', $contents);
+        $reader = new OdsReader();
+        $spreadsheet = $reader->load($this->file);
+        $sheet = $spreadsheet->getActiveSheet();
+        self::assertSame('FirstCell', $sheet->getCell('A1')->getValue());
+        $spreadsheet->disconnectWorksheets();
+    }
+}