Pattern Fill style should default to 'solid' if there is a pattern fill with colour but no style

CHANGELOG.md

@@ -26,7 +26,7 @@ and this project adheres to [Semantic Versioning](https://semver.org).
 - Nothing.
 
 ### Fixed
-
+- Correct default fill style for conditional without a pattern defined [Issue #2035](https://github.com/PHPOffice/PhpSpreadsheet/issues/2035) [PR #2050](https://github.com/PHPOffice/PhpSpreadsheet/pull/2050)
 - Fixed issue where array key check for existince before accessing arrays in Xlsx.php. [PR #1970](https://github.com/PHPOffice/PhpSpreadsheet/pull/1970)
 - Fixed issue with quoted strings in number format mask rendered with toFormattedString() [Issue 1972#](https://github.com/PHPOffice/PhpSpreadsheet/issues/1972) [PR #1978](https://github.com/PHPOffice/PhpSpreadsheet/pull/1978)
 - Fixed issue with percentage formats in number format mask rendered with toFormattedString() [Issue 1929#](https://github.com/PHPOffice/PhpSpreadsheet/issues/1929) [PR #1928](https://github.com/PHPOffice/PhpSpreadsheet/pull/1928)

src/PhpSpreadsheet/Reader/Xlsx/Styles.php

@@ -103,17 +103,21 @@ public static function readFillStyle(Fill $fillStyle, SimpleXMLElement $fillStyl
                 self::readColor(self::getArrayItem($gradientFill->xpath('sml:stop[@position=1]'))->color)
             );
         } elseif ($fillStyleXml->patternFill) {
-            $patternType = (string) $fillStyleXml->patternFill['patternType'] != ''
-                ? (string) $fillStyleXml->patternFill['patternType']
-                : Fill::FILL_NONE;
-
-            $fillStyle->setFillType($patternType);
+            $defaultFillStyle = Fill::FILL_NONE;
             if ($fillStyleXml->patternFill->fgColor) {
                 $fillStyle->getStartColor()->setARGB(self::readColor($fillStyleXml->patternFill->fgColor, true));
+                $defaultFillStyle = Fill::FILL_SOLID;
             }
             if ($fillStyleXml->patternFill->bgColor) {
                 $fillStyle->getEndColor()->setARGB(self::readColor($fillStyleXml->patternFill->bgColor, true));
+                $defaultFillStyle = Fill::FILL_SOLID;
             }
+
+            $patternType = (string) $fillStyleXml->patternFill['patternType'] != ''
+                ? (string) $fillStyleXml->patternFill['patternType']
+                : $defaultFillStyle;
+
+            $fillStyle->setFillType($patternType);
         }
     }
 

src/PhpSpreadsheet/Writer/Xls/Style/ColorMap.php

@@ -75,6 +75,16 @@ public static function lookup(Color $color, int $defaultIndex = 0x00): int
             return self::$colorMap["#{$colorRgb}"];
         }
 
+//      TODO Try and map RGB value to nearest colour within the define pallette
+//        $red =  Color::getRed($colorRgb, false);
+//        $green = Color::getGreen($colorRgb, false);
+//        $blue = Color::getBlue($colorRgb, false);
+
+//        $paletteSpace = 3;
+//        $newColor = ($red * $paletteSpace / 256) * ($paletteSpace * $paletteSpace) +
+//            ($green * $paletteSpace / 256) * $paletteSpace +
+//            ($blue * $paletteSpace / 256);
+
         return $defaultIndex;
     }
 }

tests/PhpSpreadsheetTests/Reader/Xlsx/DefaultFillTest.php

@@ -29,4 +29,15 @@ public function testDefaultFill(): void
         self::assertSame('none', $sheet->getCell('J16')->getStyle()->getFill()->getFillType());
         self::assertSame('solid', $sheet->getCell('C2')->getStyle()->getFill()->getFillType());
     }
+
+    public function testDefaultConditionalFill(): void
+    {
+        // default fill pattern for a conditional style where the filltype is not defined
+        $filename = 'tests/data/Reader/XLSX/pr2050cf-fill.xlsx';
+        $reader = IOFactory::createReader('Xlsx');
+        $spreadsheet = $reader->load($filename);
+
+        $style = $spreadsheet->getActiveSheet()->getConditionalStyles('A1')[0]->getStyle();
+        self::assertSame('solid', $style->getFill()->getFillType());
+    }
 }