WIP Handle REF Error as Part of Range

Fix PHPOffice#3453. User sets a valid formula (e.g. `=SUM(Sheet2!B1:Sheet2!B3)`), and then does something to invalidate the formula (e.g. delete Sheet2). Excel changes the formula to `SUM(#REF!:#REF!)` when the spreadsheet is saved; apparently someone thought this was a good idea. But PhpSpreadsheet (a) used to throw an Exception when it evaluated the formula, and (b) now gives a result of `0` when evaluating the formula. Neither is ideal. It would be better to propagate the `#REF!` error.

It is likely that more tests are needed, which is why I will keep this in draft status for a bit.

src/PhpSpreadsheet/Calculation/Calculation.php

@@ -4364,8 +4364,12 @@ private function internalParseFormula($formula, ?Cell $cell = null)
                                 $rangeStartCellRef = $output[count($output) - 2]['value'] ?? '';
                             }
                             preg_match('/^' . self::CALCULATION_REGEXP_CELLREF . '$/miu', $rangeStartCellRef, $rangeStartMatches);
-                            if ($rangeStartMatches[2] > '') {
-                                $val = $rangeStartMatches[2] . '!' . $val;
+                            if (array_key_exists(2, $rangeStartMatches)) {
+                                if ($rangeStartMatches[2] > '') {
+                                    $val = $rangeStartMatches[2] . '!' . $val;
+                                }
+                            } else {
+                                $val = Information\ExcelError::REF();
                             }
                         } else {
                             $rangeStartCellRef = $output[count($output) - 1]['value'] ?? '';
@@ -4434,6 +4438,8 @@ private function internalParseFormula($formula, ?Cell $cell = null)
                                 }
                                 $val = $address;
                             }
+                        } elseif ($val === Information\ExcelError::REF()) {
+                            $stackItemReference = $val;
                         } else {
                             $startRowColRef = $output[count($output) - 1]['value'] ?? '';
                             [$rangeWS1, $startRowColRef] = Worksheet::extractSheetTitle($startRowColRef, true);
@@ -4793,7 +4799,7 @@ private function processTokenStack($tokens, $cellID = null, ?Cell $cell = null)
                                 }
                             }
                         }
-                        if (strpos($operand1Data['reference'], '!') !== false) {
+                        if (strpos($operand1Data['reference'] ?? '', '!') !== false) {
                             [$sheet1, $operand1Data['reference']] = Worksheet::extractSheetTitle($operand1Data['reference'], true);
                         } else {
                             $sheet1 = ($pCellWorksheet !== null) ? $pCellWorksheet->getTitle() : '';
@@ -4830,10 +4836,21 @@ private function processTokenStack($tokens, $cellID = null, ?Cell $cell = null)
 
                             $oData = array_merge(explode(':', $operand1Data['reference']), explode(':', $operand2Data['reference']));
                             $oCol = $oRow = [];
+                            $breakNeeded = false;
                             foreach ($oData as $oDatum) {
-                                $oCR = Coordinate::coordinateFromString($oDatum);
-                                $oCol[] = Coordinate::columnIndexFromString($oCR[0]) - 1;
-                                $oRow[] = $oCR[1];
+                                try {
+                                    $oCR = Coordinate::coordinateFromString($oDatum);
+                                    $oCol[] = Coordinate::columnIndexFromString($oCR[0]) - 1;
+                                    $oRow[] = $oCR[1];
+                                } catch (\Exception $e) {
+                                    $stack->push('Error', Information\ExcelError::REF(), null);
+                                    $breakNeeded = true;
+
+                                    break;
+                                }
+                            }
+                            if ($breakNeeded) {
+                                break;
                             }
                             $cellRef = Coordinate::stringFromColumnIndex(min($oCol) + 1) . min($oRow) . ':' . Coordinate::stringFromColumnIndex(max($oCol) + 1) . max($oRow);
                             if ($pCellParent !== null && $this->spreadsheet !== null) {

tests/PhpSpreadsheetTests/RefRangeTest.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace PhpOffice\PhpSpreadsheetTests;
+
+use PhpOffice\PhpSpreadsheet\Reader\Xlsx;
+use PhpOffice\PhpSpreadsheet\Spreadsheet;
+use PHPUnit\Framework\TestCase;
+
+class RefRangeTest extends TestCase
+{
+    /**
+     * @param int|string $expectedResult
+     *
+     * @dataProvider providerRefRange
+     */
+    public function testRefRange($expectedResult, string $rangeString): void
+    {
+        $spreadsheet = new Spreadsheet();
+        $sheet = $spreadsheet->getActiveSheet();
+        $sheet->getCell('A1')->setValue("=SUM($rangeString)");
+        self::assertSame($expectedResult, $sheet->getCell('A1')->getCalculatedValue());
+        $spreadsheet->disconnectWorksheets();
+    }
+
+    public function providerRefRange(): array
+    {
+        return [
+            'normal range' => [0, 'B1:B2'],
+            'ref as end of range' => ['#REF!', 'B1:#REF!'],
+            'ref as start of range' => ['#REF!', '#REF!:B2'],
+            'ref as both parts of range' => ['#REF!', '#REF!:#REF!'],
+            'using indirect for ref' => ['#REF!', 'B1:INDIRECT("XYZ")'],
+        ];
+    }
+
+    public function testRefRangeRead(): void
+    {
+        $reader = new Xlsx();
+        $spreadsheet = $reader->load('tests/data/Reader/XLSX/issue.3453.xlsx');
+        $sheet = $spreadsheet->getActiveSheet();
+        self::assertSame(0, $sheet->getCell('H1')->getCalculatedValue());
+        self::assertSame('#REF!', $sheet->getCell('H2')->getCalculatedValue());
+        $spreadsheet->disconnectWorksheets();
+    }
+}