Don't corrupt file when using chart with fill color

When the fill color property of `DataSeries.plotLabel` using a
DataSeriesValues on a line chart is set, the XLSX file written
is corrupted, and MSExcel2016 removes the drawing1.xml if forced open.

This problem was already documented on issue #589 along with a possible
solution. So all credits go to @madrussa. I am only submitting the PR.

Fixes #589
Closes #1930

src/PhpSpreadsheet/Writer/Xlsx/Chart.php

@@ -1058,7 +1058,7 @@ private function writePlotGroup(?DataSeries $plotGroup, $groupType, XMLWriter $o
             $objWriter->startElement('c:ser');
 
             $plotLabel = $plotGroup->getPlotLabelByIndex($plotSeriesIdx);
-            if ($plotLabel) {
+            if ($plotLabel && $groupType !== DataSeries::TYPE_LINECHART) {
                 $fillColor = $plotLabel->getFillColor();
                 if ($fillColor !== null && !is_array($fillColor)) {
                     $objWriter->startElement('c:spPr');
@@ -1116,6 +1116,15 @@ private function writePlotGroup(?DataSeries $plotGroup, $groupType, XMLWriter $o
                 if ($groupType == DataSeries::TYPE_STOCKCHART) {
                     $objWriter->startElement('a:noFill');
                     $objWriter->endElement();
+                } elseif ($plotLabel) {
+                    $fillColor = $plotLabel->getFillColor();
+                    if (is_string($fillColor)) {
+                        $objWriter->startElement('a:solidFill');
+                        $objWriter->startElement('a:srgbClr');
+                        $objWriter->writeAttribute('val', $fillColor);
+                        $objWriter->endElement();
+                        $objWriter->endElement();
+                    }
                 }
                 $objWriter->endElement();
                 $objWriter->endElement();

tests/PhpSpreadsheetTests/Writer/Xlsx/Issue589Test.php

@@ -0,0 +1,162 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheetTests\Writer\Xlsx;
+
+use DOMDocument;
+use DOMNode;
+use PhpOffice\PhpSpreadsheet\Chart\Chart;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeries;
+use PhpOffice\PhpSpreadsheet\Chart\DataSeriesValues;
+use PhpOffice\PhpSpreadsheet\Chart\PlotArea;
+use PhpOffice\PhpSpreadsheet\Shared\File;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheet\Writer\Xlsx as Writer;
+use PHPUnit\Framework\TestCase;
+use ZipArchive;
+
+class Issue589Test extends TestCase
+{
+    /**
+     * Build a testable chart in a spreadsheet and set fill color for series.
+     *
+     * @param string|string[] $color HEX color or array with HEX colors
+     */
+    private function buildChartSpreadsheet($color): Spreadsheet
+    {
+        // Problem occurs when setting plot line color
+        // The output chart xml file is missing the a:ln tag
+        $spreadsheet = new Spreadsheet();
+        $worksheet = $spreadsheet->getActiveSheet();
+        $worksheet->fromArray(
+            [
+                [2010],
+                [12],
+                [56],
+            ]
+        );
+
+        $dataSeriesLabels = [
+            new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_STRING, 'Worksheet!$A$1', null, 1),
+        ];
+        $dataSeriesLabels[0]->setFillColor($color);
+        $dataSeriesValues = [
+            new DataSeriesValues(DataSeriesValues::DATASERIES_TYPE_NUMBER, 'Worksheet!$A$2:$A$3', null, 2),
+        ];
+
+        // Build the dataseries
+        $series = new DataSeries(
+            DataSeries::TYPE_LINECHART,
+            DataSeries::GROUPING_STACKED,
+            range(0, count($dataSeriesValues) - 1),
+            $dataSeriesLabels,
+            [],
+            $dataSeriesValues
+        );
+
+        // Set the series in the plot area
+        $plotArea = new PlotArea(null, [$series]);
+
+        // Create the chart
+        $chart = new Chart(
+            'chart1',
+            null,
+            null,
+            $plotArea
+        );
+
+        // Add the chart to the worksheet
+        $worksheet->addChart($chart);
+
+        return $spreadsheet;
+    }
+
+    public function testLineChartFill(): void
+    {
+        $outputFilename = File::temporaryFilename();
+        $spreadsheet = $this->buildChartSpreadsheet('98B954');
+        $writer = new Writer($spreadsheet);
+        $writer->setIncludeCharts(true);
+        $writer->save($outputFilename);
+
+        $zip = new ZipArchive();
+        $zip->open($outputFilename);
+        $resultChart1Raw = $zip->getFromName('xl/charts/chart1.xml');
+        $zip->close();
+        unlink($outputFilename);
+
+        $dom = new DOMDocument();
+        if ($resultChart1Raw === false) {
+            self::fail('Unable to open the chart file');
+        } else {
+            $loaded = $dom->loadXML($resultChart1Raw);
+            if (!$loaded) {
+                self::fail('Unable to load the chart xml');
+            } else {
+                $series = $dom->getElementsByTagName('ser');
+                $firstSeries = $series->item(0);
+                if ($firstSeries === null) {
+                    self::fail('The chart XML does not contain a \'ser\' tag!');
+                } else {
+                    $spPrList = $firstSeries->getElementsByTagName('spPr');
+
+                    // expect to see only one element with name 'c:spPr'
+                    self::assertCount(1, $spPrList);
+
+                    /** @var DOMNode $node */
+                    $node = $spPrList->item(0); // Get the spPr element
+                    $actualXml = $dom->saveXML($node);
+                    if ($actualXml === false) {
+                        self::fail('Failure saving the spPr element as xml string!');
+                    } else {
+                        self::assertXmlStringEqualsXmlString('<c:spPr><a:ln w="12700"><a:solidFill><a:srgbClr val="98B954"/></a:solidFill></a:ln></c:spPr>', $actualXml);
+                    }
+                }
+            }
+        }
+    }
+
+    public function testLineChartFillIgnoresColorArray(): void
+    {
+        $outputFilename = File::temporaryFilename();
+        $spreadsheet = $this->buildChartSpreadsheet(['98B954']);
+        $writer = new Writer($spreadsheet);
+        $writer->setIncludeCharts(true);
+        $writer->save($outputFilename);
+
+        $zip = new ZipArchive();
+        $zip->open($outputFilename);
+        $resultChart1Raw = $zip->getFromName('xl/charts/chart1.xml');
+        $zip->close();
+        unlink($outputFilename);
+
+        $dom = new DOMDocument();
+        if ($resultChart1Raw === false) {
+            self::fail('Unable to open the chart file');
+        } else {
+            $loaded = $dom->loadXML($resultChart1Raw);
+            if (!$loaded) {
+                self::fail('Unable to load the chart xml');
+            } else {
+                $series = $dom->getElementsByTagName('ser');
+                $firstSeries = $series->item(0);
+                if ($firstSeries === null) {
+                    self::fail('The chart XML does not contain a \'ser\' tag!');
+                } else {
+                    $spPrList = $firstSeries->getElementsByTagName('spPr');
+
+                    // expect to see only one element with name 'c:spPr'
+                    self::assertCount(1, $spPrList);
+
+                    /** @var DOMNode $node */
+                    $node = $spPrList->item(0); // Get the spPr element
+                    $actualXml = $dom->saveXML($node);
+                    if ($actualXml === false) {
+                        self::fail('Failure saving the spPr element as xml string!');
+                    } else {
+                        self::assertXmlStringEqualsXmlString('<c:spPr><a:ln w="12700"></a:ln></c:spPr>', $actualXml);
+                    }
+                }
+            }
+        }
+    }
+}