Fix incorrect quote escaping in env writer. Closes #56480

src/Illuminate/Support/Env.php

@@ -191,12 +191,11 @@ protected static function addVariableToEnvContents(string $key, mixed $value, ar
         $shouldQuote = preg_match('/^[a-zA-z0-9]+$/', $value) === 0;
 
         $lineToAddVariations = [
-            $key.'='.(is_string($value) ? '"'.addslashes($value).'"' : $value),
-            $key.'='.(is_string($value) ? "'".addslashes($value)."'" : $value),
+            $key.'='.(is_string($value) ? self::prepareQuotedValue($value) : $value),
             $key.'='.$value,
         ];
 
-        $lineToAdd = $shouldQuote ? $lineToAddVariations[0] : $lineToAddVariations[2];
+        $lineToAdd = $shouldQuote ? $lineToAddVariations[0] : $lineToAddVariations[1];
 
         if ($value === '') {
             $lineToAdd = $key.'=';
@@ -277,4 +276,35 @@ protected static function getOption($key)
                 return $value;
             });
     }
+
+    /**
+     * Wrap a string in quotes, choosing double or single quotes.
+     *
+     * @param  string  $input
+     * @return string
+     */
+    protected static function prepareQuotedValue(string $input)
+    {
+        return strpos($input, '"') !== false
+            ? "'".self::addSlashesExceptFor($input, ['"'])."'"
+            : '"'.self::addSlashesExceptFor($input, ["'"]).'"';
+    }
+
+    /**
+     * Escape a string using addslashes, excluding the specified characters from being escaped.
+     *
+     * @param  string  $value
+     * @param  array  $except
+     * @return string
+     */
+    protected static function addSlashesExceptFor(string $value, array $except = [])
+    {
+        $escaped = addslashes($value);
+
+        foreach ($except as $character) {
+            $escaped = str_replace('\\'.$character, $character, $escaped);
+        }
+
+        return $escaped;
+    }
 }