Warning: htmlspecialchars() expects parameter 1 to be string, array given in check_plain()

Thanks for reporting this.

There are only two places (three occurences) in the module, where check_plain() is used:

device_geolocation_detector_ajax()

      if (!empty($address) && is_string($address) && is_string($label)) {
        $label = check_plain($label);
        if (!is_array($address)) {
          $smart_ip_session['location'][$label] = check_plain($address);
        }

smart_ip_admin_settings_validate()

  $list = check_plain($form_state['values']['smart_ip_allowed_pages']);

The first one checking $label and $address has conditions to verify, if both of these variables are arrays. The second one is a value of textarea from the form submission. I am not sure how any of these can be an array under standard circumstances. Would it be possible to debug it a bit more to provide a backtrace, so that we can see what is the source of this problem?

Thanks!

Given that check_plain() uses the following code, how can htmlspecialchars() complain about getting an array instead of a string?

function check_plain($text) {
  return htmlspecialchars((string) $text, ENT_QUOTES, 'UTF-8');
}

I tried the following code on https://3v4l.org.

$text = array();

echo htmlspecialchars((string) $text, ENT_QUOTES, 'UTF-8'), "\n";

Except some PHP 5 versions that do not throw warnings/notices, the other PHP versions shown this.

PHP 8

Warning: Array to string conversion in /in/ruWXX on line 5
Array

PHP 4, PHP 5, PHP 7

Notice: Array to string conversion in /in/ruWXX on line 5
Array

Probably, on 2019, check_plain() did not cast its parameter to a string.

It seems the OP was using the 7.x-2.53 release. #2956717: Warning after installing and configuring Smart IP → is reported between the fixed issues for release 7.x-2.51 → .
Either this error was caused by something else that still has to be fixed, or the OP was not using the 7.x-2.53 release.

Thanks @apaderno. Yes, this casting to string in check_plain() was added to D7 core by #3254699: [D7 PHP 8.1] check_plain(): Passing null to parameter #1 check_plain() includes/bootstrap.inc, line 1907 → in February 2022. So this is another issue that could affect this original report.

Drupal 7 is no longer supported in a month. Closing old issues. If this is still something you want addressed in the current 5.x version of the module, please re-open and provide some next steps.