Php 8.4 Will Deprecate fgetcsv Parameter

As described in issue PHPOffice#4161, Php seems to be prepared to break the fgetcsv function in release 9, marking the existing usage deprecated in 8.4. This gives us a long-term problem. This PR provides a short-term solution.

src/PhpSpreadsheet/Reader/Csv.php

@@ -228,11 +228,11 @@ public function listWorksheetInfo(string $filename): array
         $delimiter = $this->delimiter ?? '';
 
         // Loop through each line of the file in turn
-        $rowData = fgetcsv($fileHandle, 0, $delimiter, $this->enclosure, $this->escapeCharacter);
+        $rowData = self::getCsv($fileHandle, 0, $delimiter, $this->enclosure, $this->escapeCharacter);
         while (is_array($rowData)) {
             ++$worksheetInfo[0]['totalRows'];
             $worksheetInfo[0]['lastColumnIndex'] = max($worksheetInfo[0]['lastColumnIndex'], count($rowData) - 1);
-            $rowData = fgetcsv($fileHandle, 0, $delimiter, $this->enclosure, $this->escapeCharacter);
+            $rowData = self::getCsv($fileHandle, 0, $delimiter, $this->enclosure, $this->escapeCharacter);
         }
 
         $worksheetInfo[0]['lastColumnLetter'] = Coordinate::stringFromColumnIndex($worksheetInfo[0]['lastColumnIndex'] + 1);
@@ -379,7 +379,7 @@ private function loadStringOrFile(string $filename, Spreadsheet $spreadsheet, bo
 
         // Loop through each line of the file in turn
         $delimiter = $this->delimiter ?? '';
-        $rowData = fgetcsv($fileHandle, 0, $delimiter, $this->enclosure, $this->escapeCharacter);
+        $rowData = self::getCsv($fileHandle, 0, $delimiter, $this->enclosure, $this->escapeCharacter);
         $valueBinder = Cell::getValueBinder();
         $preserveBooleanString = method_exists($valueBinder, 'getBooleanConversion') && $valueBinder->getBooleanConversion();
         $this->getTrue = Calculation::getTRUE();
@@ -416,7 +416,7 @@ private function loadStringOrFile(string $filename, Spreadsheet $spreadsheet, bo
                 }
                 ++$columnLetter;
             }
-            $rowData = fgetcsv($fileHandle, 0, $delimiter, $this->enclosure, $this->escapeCharacter);
+            $rowData = self::getCsv($fileHandle, 0, $delimiter, $this->enclosure, $this->escapeCharacter);
             ++$currentRow;
         }
 
@@ -649,4 +649,27 @@ public function setSheetNameIsFileName(bool $sheetNameIsFileName): self
 
         return $this;
     }
+
+    /**
+     * Php8.4 deprecates use of anything other than null string
+     * as escape Character.
+     *
+     * @param resource $stream
+     * @param null|int<0, max> $length
+     *
+     * @return array<int,?string>|false
+     */
+    private static function getCsv(
+        $stream,
+        ?int $length = null,
+        string $separator = ',',
+        string $enclosure = '"',
+        string $escape = '\\'
+    ): array|false {
+        if (PHP_VERSION_ID >= 80400 && $escape !== '') {
+            return @fgetcsv($stream, $length, $separator, $enclosure, $escape);
+        }
+
+        return fgetcsv($stream, $length, $separator, $enclosure, $escape);
+    }
 }