XLSX Reader and Empty Fill Tag (#2011)

Openpyxl can generate the xml tag `<patternFill/>`, possibly even as a default style. Excel has no problem with this, treating it as "fill none", but PhpSpreadsheet has a glitch because it treats it as "fill solid white". So, when PhpSpreadsheet loads and saves such a file, the result at first appears as if gridlines are disabled; in fact, the gridlines are merely invisible behind the cells with their solid white fill. This PR makes PhpSpreadsheet behave the same as Excel in this circumstance.

Co-authored-by: Mark Baker <mark@lange.demon.co.uk>

src/PhpSpreadsheet/Reader/Xlsx.php

@@ -30,6 +30,7 @@ use PhpOffice\PhpSpreadsheet\Spreadsheet;
 use PhpOffice\PhpSpreadsheet\Style\Border;
 use PhpOffice\PhpSpreadsheet\Style\Borders;
 use PhpOffice\PhpSpreadsheet\Style\Color;
+use PhpOffice\PhpSpreadsheet\Style\Fill;
 use PhpOffice\PhpSpreadsheet\Style\NumberFormat;
 use PhpOffice\PhpSpreadsheet\Style\Protection;
 use PhpOffice\PhpSpreadsheet\Style\Style;
@@ -1646,7 +1647,7 @@ class Xlsx extends BaseReader
                 $docStyle->getFill()->getStartColor()->setARGB(self::readColor(self::getArrayItem($gradientFill->xpath('sml:stop[@position=0]'))->color));
                 $docStyle->getFill()->getEndColor()->setARGB(self::readColor(self::getArrayItem($gradientFill->xpath('sml:stop[@position=1]'))->color));
             } elseif ($style->fill->patternFill) {
-                $patternType = (string) $style->fill->patternFill['patternType'] != '' ? (string) $style->fill->patternFill['patternType'] : 'solid';
+                $patternType = (string) $style->fill->patternFill['patternType'] != '' ? (string) $style->fill->patternFill['patternType'] : Fill::FILL_NONE;
                 $docStyle->getFill()->setFillType($patternType);
                 if ($style->fill->patternFill->fgColor) {
                     $docStyle->getFill()->getStartColor()->setARGB(self::readColor($style->fill->patternFill->fgColor, true));

src/PhpSpreadsheet/Reader/Xlsx/Styles.php

@@ -97,7 +97,7 @@ class Styles extends BaseParserClass
             $fillStyle->getStartColor()->setARGB(self::readColor(self::getArrayItem($gradientFill->xpath('sml:stop[@position=0]'))->color));
             $fillStyle->getEndColor()->setARGB(self::readColor(self::getArrayItem($gradientFill->xpath('sml:stop[@position=1]'))->color));
         } elseif ($fillStyleXml->patternFill) {
-            $patternType = (string) $fillStyleXml->patternFill['patternType'] != '' ? (string) $fillStyleXml->patternFill['patternType'] : 'solid';
+            $patternType = (string) $fillStyleXml->patternFill['patternType'] != '' ? (string) $fillStyleXml->patternFill['patternType'] : Fill::FILL_NONE;
             $fillStyle->setFillType($patternType);
             if ($fillStyleXml->patternFill->fgColor) {
                 $fillStyle->getStartColor()->setARGB(self::readColor($fillStyleXml->patternFill->fgColor, true));

tests/PhpSpreadsheetTests/Reader/Xlsx/DefaultFillTest.php

@@ -0,0 +1,32 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheetTests\Reader;
+
+use PhpOffice\PhpSpreadsheet\IOFactory;
+use PHPUnit\Framework\TestCase;
+
+class DefaultFillTest extends TestCase
+{
+    public function testDefaultFill(): void
+    {
+        // default fill pattern doesn't specify filltype
+        $filename = 'tests/data/Reader/XLSX/pr1769g.py.xlsx';
+        $file = 'zip://';
+        $file .= $filename;
+        $file .= '#xl/styles.xml';
+        $data = file_get_contents($file);
+        // confirm that file contains expected empty xml tag
+        if ($data === false) {
+            self::fail('Unable to read file');
+        } else {
+            self::assertStringContainsString('<patternFill/>', $data);
+        }
+        $reader = IOFactory::createReader('Xlsx');
+        $spreadsheet = $reader->load($filename);
+        $sheet = $spreadsheet->getActiveSheet();
+        self::assertSame('none', $sheet->getCell('A1')->getStyle()->getFill()->getFillType());
+        self::assertSame('none', $sheet->getCell('D4')->getStyle()->getFill()->getFillType());
+        self::assertSame('none', $sheet->getCell('J16')->getStyle()->getFill()->getFillType());
+        self::assertSame('solid', $sheet->getCell('C2')->getStyle()->getFill()->getFillType());
+    }
+}