Address Some Chart Problems

src/PhpSpreadsheet/Writer/Xlsx.php

@@ -410,6 +410,9 @@ public function save($filename, int $flags = 0): void
                     }
                 }
             }
+            if (isset($unparsedLoadedData['sheets'][$sheetCodeName]['drawingOriginalIds']) && !isset($zipContent['xl/drawings/drawing' . ($i + 1) . '.xml'])) {
+                $zipContent['xl/drawings/drawing' . ($i + 1) . '.xml'] = '<xml></xml>';
+            }
 
             // Add comment relationship parts
             $legacy = $unparsedLoadedData['sheets'][$this->spreadSheet->getSheet($i)->getCodeName()]['legacyDrawing'] ?? null;

src/PhpSpreadsheet/Writer/Xlsx/Chart.php

@@ -169,8 +169,8 @@ private function writeTitle(XMLWriter $objWriter, ?Title $title = null): void
         $objWriter->endElement();
 
         $caption = $title->getCaption();
-        if ((is_array($caption)) && (count($caption) > 0)) {
-            $caption = $caption[0];
+        if (is_array($caption)) {
+            $caption = $caption[0] ?? '';
         }
         $this->getParentWriter()->getWriterPartstringtable()->writeRichTextForCharts($objWriter, $caption, 'a');
 

tests/PhpSpreadsheetTests/Reader/Xlsx/Issue3767Test.php

@@ -0,0 +1,88 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpOffice\PhpSpreadsheetTests\Reader\Xlsx;
+
+use PhpOffice\PhpSpreadsheet\Reader\Xlsx as XlsxReader;
+use PhpOffice\PhpSpreadsheet\Shared\File;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx as XlsxWriter;
+use PhpOffice\PhpSpreadsheetTests\Functional\AbstractFunctional;
+
+class Issue3767Test extends AbstractFunctional
+{
+    // some weirdness with this file, including the fact that it has a
+    // title ('Chart Title') which I cannot find anywhere in the xml.
+    private static string $testbook = 'tests/data/Reader/XLSX/issue.3767.xlsx';
+
+    private string $tempfile = '';
+
+    protected function tearDown(): void
+    {
+        if ($this->tempfile !== '') {
+            unlink($this->tempfile);
+            $this->tempfile = '';
+        }
+    }
+
+    public function readCharts(XlsxReader $reader): void
+    {
+        $reader->setIncludeCharts(true);
+    }
+
+    public function writeCharts(XlsxWriter $writer): void
+    {
+        $writer->setIncludeCharts(true);
+    }
+
+    public function testReadWithoutCharts(): void
+    {
+        $reader = new XlsxReader();
+        //$this->readCharts($reader); // Commented out - don't want to read charts.
+        $spreadsheet = $reader->load(self::$testbook);
+        $sheet = $spreadsheet->getActiveSheet();
+        $charts = $sheet->getChartCollection();
+        self::assertCount(0, $charts);
+        $this->tempfile = File::temporaryFileName();
+        $writer = new XlsxWriter($spreadsheet);
+        $this->writeCharts($writer);
+        $writer->save($this->tempfile);
+        $spreadsheet->disconnectWorksheets();
+        $file = 'zip://';
+        $file .= $this->tempfile;
+        $file .= '#xl/worksheets/_rels/sheet1.xml.rels';
+        $data = (string) file_get_contents($file);
+        // PhpSpreadsheet still generates this target even though charts aren't included
+        self::assertStringContainsString('Target="../drawings/drawing1.xml"', $data);
+        $file = 'zip://';
+        $file .= $this->tempfile;
+        $file .= '#xl/drawings/drawing1.xml';
+        $data = file_get_contents($file);
+        self::assertSame('<xml></xml>', $data); // fake file because rels needs it
+    }
+
+    public function testReadWithCharts(): void
+    {
+        $reader = new XlsxReader();
+        $this->readCharts($reader);
+        $spreadsheet = $reader->load(self::$testbook);
+        $xsheet = $spreadsheet->getActiveSheet();
+        $xcharts = $xsheet->getChartCollection();
+        self::assertCount(1, $xcharts);
+        /** @var callable */
+        $callableReader = [$this, 'readCharts'];
+        /** @var callable */
+        $callableWriter = [$this, 'writeCharts'];
+        $reloadedSpreadsheet = $this->writeAndReload($spreadsheet, 'Xlsx', $callableReader, $callableWriter);
+        $spreadsheet->disconnectWorksheets();
+        $sheet = $reloadedSpreadsheet->getActiveSheet();
+        $charts = $xsheet->getChartCollection();
+        self::assertCount(1, $charts);
+        // In Excel, a default title ('Chart Title') is shown.
+        // I can't find that anywhere in the Xml.
+        self::assertSame('', $charts[0]?->getTitle()?->getCaptionText());
+        // Just test anything on the chart.
+        self::assertSame($sheet->getCell('B2')->getValue(), $charts[0]->getPlotArea()?->getPlotGroup()[0]->getPlotValues()[0]->getDataValues()[0]);
+        $reloadedSpreadsheet->disconnectWorksheets();
+    }
+}