Inconsistency Between Actual and Declared Type - Minor Break

src/PhpSpreadsheet/Cell/Cell.php

@@ -457,12 +457,9 @@ public function getDataType(): string
      */
     public function setDataType($dataType): self
     {
-        if ($dataType == DataType::TYPE_STRING2) {
-            $dataType = DataType::TYPE_STRING;
-        }
-        $this->dataType = $dataType;
+        $this->setValueExplicit($this->value, $dataType);
 
-        return $this->updateInCollection();
+        return $this;
     }
 
     /**

tests/PhpSpreadsheetTests/Cell/DataType2Test.php

@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpOffice\PhpSpreadsheetTests\Cell;
+
+use PhpOffice\PhpSpreadsheet\Cell\DataType;
+use PhpOffice\PhpSpreadsheet\Exception as PhpSpreadsheetException;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PHPUnit\Framework\TestCase;
+
+class DataType2Test extends TestCase
+{
+    public function testSetDataType(): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $sheet->getCell('A1')->setValue(28.1);
+        self::assertSame(28.1, $sheet->getCell('A1')->getValue());
+        self::assertSame('28.1', (string) $sheet->getCell('A1'));
+        $sheet->getCell('A1')->setDataType(DataType::TYPE_STRING);
+        self::assertSame('28.1', $sheet->getCell('A1')->getValue());
+        $sheet->getCell('A1')->setDataType(DataType::TYPE_NUMERIC);
+        self::assertSame(28.1, $sheet->getCell('A1')->getValue());
+        $sheet->getCell('A1')->setDataType(DataType::TYPE_STRING2);
+        self::assertSame('28.1', $sheet->getCell('A1')->getValue());
+        $sheet->getCell('A1')->setDataType(DataType::TYPE_INLINE);
+        self::assertSame('28.1', $sheet->getCell('A1')->getValue());
+        $sheet->getCell('A1')->setDataType(DataType::TYPE_BOOL);
+        self::assertTrue($sheet->getCell('A1')->getValue());
+        $sheet->getCell('A1')->setDataType(DataType::TYPE_NUMERIC);
+        self::assertSame(1, $sheet->getCell('A1')->getValue());
+
+        $sheet->getCell('A2')->setValue('X');
+
+        try {
+            $sheet->getCell('A2')->setDataType(DataType::TYPE_NUMERIC);
+        } catch (PhpSpreadsheetException $e) {
+            self::assertSame('Invalid numeric value for datatype Numeric', $e->getMessage());
+        }
+
+        $spreadsheet->disconnectWorksheets();
+    }
+}

tests/PhpSpreadsheetTests/Writer/Xlsx/Issue3711Test.php

@@ -0,0 +1,32 @@
+<?php
+
+declare(strict_types=1);
+
+namespace PhpOffice\PhpSpreadsheetTests\Writer\Xlsx;
+
+use PhpOffice\PhpSpreadsheet\Cell\DataType;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PhpOffice\PhpSpreadsheetTests\Functional\AbstractFunctional;
+
+class Issue3711Test extends AbstractFunctional
+{
+    public function testIssue3711(): void
+    {
+        // Issue 3711 - float being used as index in StringTable.
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $sheet->getCell('A1')->setValue('21.5');
+        self::assertSame(21.5, $sheet->getCell('A1')->getValue());
+        $sheet->getCell('A1')->setDataType(DataType::TYPE_STRING);
+        $sheet->getCell('A2')->setValue('21');
+        self::assertSame(21, $sheet->getCell('A2')->getValue());
+        $sheet->getCell('A2')->setDataType(DataType::TYPE_STRING);
+
+        $reloadedSpreadsheet = $this->writeAndReload($spreadsheet, 'Xlsx');
+        $spreadsheet->disconnectWorksheets();
+        $rsheet = $reloadedSpreadsheet->getActiveSheet();
+        self::assertSame('21.5', $rsheet->getCell('A1')->getValue());
+        self::assertSame('21', $rsheet->getCell('A2')->getValue());
+        $reloadedSpreadsheet->disconnectWorksheets();
+    }
+}