views_json:Hexadecimal encoding options are not recognized in style settings for use with other bitmask options in json_encode()

Under settings for the JSON output style, when attempting to use the multi-select form field for the Hexadecimal Encoding options (ENCODE TAGS, ENCODE APOSTROPHES) to add to the json_encode() call, value(s) selected do not persist after clicking "Apply".

The other checkbox options are correctly interpolated into the bitmask value for the optional [int] $options parameter for json_encode(). See: http://php.net/manual/en/function.json-encode.php

The specific options that are not recognized are:
JSON_HEX_TAG
JSON_HEX_APOS
JSON_HEX_QUOT
JSON_HEX_AMP

This is for 2 reasons:

#1: In views/plugins/views_plugin_style_json.inc - A mismatch in the array keys in option_definition() and options_form() for $options['encoding']['contains']['char_encoding'] and then later incorrectly used as $this->options['json_char_encoding'] instead of $this->options['char_encoding']

$form['char_encoding'] = array(
      '#type' => 'select',
      '#title' => t('Hexadecimal (base 16) encoding'),
      '#options' => array(
        'JSON_HEX_TAG' => t('Encode tags'),
        'JSON_HEX_APOS' => t('Encode apostrophe'),
        'JSON_HEX_QUOT' => t('Encode quotes'),
        'JSON_HEX_AMP' => t('Encode ampersand'),
      ),
      '#multiple' => TRUE,
      '#default_value' => $this->options['json_char_encoding'],
      '#description' => t('You can combine multiple options.'),
);

Code should be:

$form['char_encoding'] = array(
      '#type' => 'select',
      '#title' => t('Hexadecimal (base 16) encoding'),
      '#options' => array(
        'JSON_HEX_TAG' => t('Encode tags'),
        'JSON_HEX_APOS' => t('Encode apostrophe'),
        'JSON_HEX_QUOT' => t('Encode quotes'),
        'JSON_HEX_AMP' => t('Encode ampersand'),
      ),
      '#multiple' => TRUE,
      '#default_value' => $this->options['char_encoding'],
      '#description' => t('You can combine multiple options.'),
);

2 - In views/theme/view_view_json_style.theme.inc: The multi-select for $form[char_encoding] form field array is never iterated to build the bitmask.

$bitmask = NULL;
  foreach($bitmasks as $mask_key => $_bitmask) {
    if(isset($options[$mask_key]) && $options[$mask_key] && !is_array($options[$mask_key])) {
      $bitmask = $bitmask | constant($_bitmask['bitmask']);
    }
  }
  $vars['bitmask'] = $bitmask;

The problem is with the !is_array() call.
The $form[char_encoding] will be an array, as it is a multiple
form field.
So, the array is never included in the bitmask calculation.

Should be:

$bitmask = NULL;
  foreach($bitmasks as $mask_key => $_bitmask) {
    if(isset($options[$mask_key]) && $options[$mask_key]) {
      if(!is_array($options[$mask_key])){
        $bitmask = $bitmask | constant($_bitmask['bitmask']);
      }
      else{ //the multi-select array for Hexadecimal character encoding options from options array
        foreach($options[$mask_key] as $char_encode){
          $bitmask = $bitmask | constant($char_encode);  
        }
      }
    }
  }
  $vars['bitmask'] = $bitmask;

Steps to replicate:

1- Set up a view using JSON output style.
2- Under display style settings for JSON, select one (or many) of the Hexadecimal Encoding options in the multiple
form field.
3- Click Apply
4 - Revisit the settings, notice no value persists.

Am attaching patches in comments.