Some Long-Term Prep

Enable us to determine if user has explicitly changed escape character vs. using default.

Author: oleibman

src/PhpSpreadsheet/Reader/Csv.php

@@ -62,8 +62,19 @@ class Csv extends BaseReader
 
     /**
      * The character that can escape the enclosure.
+     * This will probably become unsupported in Php 9.
+     * Not yet ready to mark deprecated in order to give users
+     * a migration path.
      */
-    private string $escapeCharacter = '\\';
+    private ?string $escapeCharacter = null;
+
+    /**
+     * The character that will be supplied to fgetcsv
+     * when escapeCharacter is null.
+     * It is anticipated that it will conditionally be set
+     * to null-string for Php9 and above.
+     */
+    private static string $defaultEscapeCharacter = '\\';
 
     /**
      * Callback for setting defaults in construction.
@@ -185,7 +196,7 @@ protected function inferSeparator(): void
             return;
         }
 
-        $inferenceEngine = new Delimiter($this->fileHandle, $this->escapeCharacter, $this->enclosure);
+        $inferenceEngine = new Delimiter($this->fileHandle, $this->escapeCharacter ?? self::$defaultEscapeCharacter, $this->enclosure);
 
         // If number of lines is 0, nothing to infer : fall back to the default
         if ($inferenceEngine->linesCounted() === 0) {
@@ -527,6 +538,11 @@ public function getContiguous(): bool
         return $this->contiguous;
     }
 
+    /**
+     * Php9 intends to drop support for this parameter in fgetcsv.
+     * Not yet ready to mark deprecated in order to give users
+     * a migration path.
+     */
     public function setEscapeCharacter(string $escapeCharacter): self
     {
         $this->escapeCharacter = $escapeCharacter;
@@ -536,7 +552,7 @@ public function setEscapeCharacter(string $escapeCharacter): self
 
     public function getEscapeCharacter(): string
     {
-        return $this->escapeCharacter;
+        return $this->escapeCharacter ?? self::$defaultEscapeCharacter;
     }
 
     /**
@@ -664,8 +680,9 @@ private static function getCsv(
         ?int $length = null,
         string $separator = ',',
         string $enclosure = '"',
-        string $escape = '\\'
+        ?string $escape = null
     ): array|false {
+        $escape = $escape ?? self::$defaultEscapeCharacter;
         if (PHP_VERSION_ID >= 80400 && $escape !== '') {
             return @fgetcsv($stream, $length, $separator, $enclosure, $escape);
         }