Bug 2061470 - Don't drop __proto__ from webRequest bodies r=rpl

  enctype="multipart/form-data"

  >

<input type="text" name="textInput2" value="value2">

<input type="text" name="__proto__" value="regression test for bug 2061470">

<input type="file" name="testFile">

<input type="file" name="emptyFile">

</form>

    }

    let action = new URL(form.action);

    let formData = new FormData(form);

    let webRequestFD = {};

    let updateActionURL = () => {

      let webRequestFD = {};

      for (let name of formData.keys()) {

        webRequestFD[name] = name in uploads ? [uploads[name].fileName] : formData.getAll(name);

        if (Object.hasOwn(webRequestFD, name)) {

          // Ignore duplicate keys; formData.getAll already read all values.

          continue;

        }

        const value = Object.hasOwn(uploads, name) ? [uploads[name].fileName] : formData.getAll(name);

        // Cannot use webRequestFD[name] = value, because for "__proto__" as

        // name, that would trigger the Object.prototype.__proto__ setter

        // instead of defining a data property.

        Object.defineProperty(webRequestFD, name, { value, enumerable: true });

      }

      action.searchParams.set("upload", JSON.stringify(webRequestFD));

      action.searchParams.set("enctype", form.enctype);

  }

}

/**

 * Creates a new Object with a corresponding property for every

 * key-value pair in the given Map.

 *

 * @param {Map} map

 *        The map to convert.

 * @returns {object}

 */

function mapToObject(map) {

  let result = {};

  for (let [key, value] of map) {

    result[key] = value;

  }

  return result;

}

/**

 * Rewinds the given seekable input stream to its beginning, and catches

 * any resulting errors.

  try {

    let formData = parseFormData(stream, channel, lenient);

    if (formData) {

      return mapToObject(formData);

      return Object.fromEntries(formData);

    }

  } catch (e) {

    Cu.reportError(e);