PHP Deprecated in qtranslate_utils.php

[sviluppomania]

PHP Deprecated: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in /plugins/qtranslate-xt/qtranslate_utils.php on line 389

[herrvigg]

Somehow related to #966 and #1092.

[herrvigg]

Can you explain how to reproduce this? Or get more traces from a callstack?

[sviluppomania]

Hi,
i got it through active WP Debug.

[herrvigg]

This is how you detected it, but how are we supposed to reproduce it? What is the context? The data?

[sviluppomania]

It is an error that occurs only front end

[herrvigg]

Sorry but this doesn't help, please provide better information so we can reproduce it. This is way too fuzzy. We need to understand the context, with data, traces, call stack, ...

[Juje]

@herrvigg The error he is most likely talking about is this one:

ErrorException: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in file htdocs/content/plugins/qtranslate-xt/qtranslate_utils.php on line 389
Stack trace:
  1. ErrorException->() htdocs/content/plugins/qtranslate-xt/qtranslate_utils.php:389
  2. preg_match() htdocs/content/plugins/qtranslate-xt/qtranslate_utils.php:389
  3. qtranxf_isMultilingual() htdocs/content/plugins/qtranslate-xt/qtranslate_frontend.php:767
  4. qtranxf_translate_metadata() htdocs/content/plugins/qtranslate-xt/qtranslate_frontend.php:843
  5. qtranxf_filter_usermeta() htdocs/cms/wp-includes/class-wp-hook.php:310
  6. WP_Hook->apply_filters() htdocs/cms/wp-includes/plugin.php:205
  7. apply_filters() htdocs/cms/wp-includes/meta.php:632
  8. get_metadata_raw() htdocs/cms/wp-includes/meta.php:571
  9. get_metadata() htdocs/cms/wp-includes/user.php:1159
 10. get_user_meta() htdocs/cms/wp-includes/class-wp-user.php:324
 11. WP_User->__get() htdocs/cms/wp-includes/l10n.php:109
 12. get_user_locale() htdocs/content/plugins/groups/lib/core/class-groups-controller.php:180
 13. Groups_Controller->get_mofile() htdocs/content/plugins/groups/lib/core/class-groups-controller.php:195
 14. Groups_Controller->load_textdomain_mofile() htdocs/cms/wp-includes/class-wp-hook.php:308
 15. WP_Hook->apply_filters() htdocs/cms/wp-includes/plugin.php:205
 16. apply_filters() htdocs/cms/wp-includes/l10n.php:759
 17. load_textdomain() htdocs/content/plugins/copy-the-code/classes/class-copy-the-code.php:98
 18. Copy_The_Code->localization_setup() htdocs/cms/wp-includes/class-wp-hook.php:308
 19. WP_Hook->apply_filters() htdocs/cms/wp-includes/class-wp-hook.php:332
 20. WP_Hook->do_action() htdocs/cms/wp-includes/plugin.php:517
 21. do_action() htdocs/cms/wp-settings.php:480
 22. require_once() htdocs/wp-config.php:32
 23. require_once() htdocs/cms/wp-load.php:55
 24. require_once() htdocs/cms/wp-blog-header.php:13
 25. require() htdocs/index.php:17

Which happens over here: https://github.com/qtranslate/qtranslate-xt/blob/master/qtranslate_utils.php#L389
This error happened on the latest version on PHP 8.1.

[sviluppomania]

@herrvigg

@herrvigg The error he is most likely talking about is this one:

ErrorException: preg_match(): Passing null to parameter #2 ($subject) of type string is deprecated in file htdocs/content/plugins/qtranslate-xt/qtranslate_utils.php on line 389
Stack trace:
  1. ErrorException->() htdocs/content/plugins/qtranslate-xt/qtranslate_utils.php:389
  2. preg_match() htdocs/content/plugins/qtranslate-xt/qtranslate_utils.php:389
  3. qtranxf_isMultilingual() htdocs/content/plugins/qtranslate-xt/qtranslate_frontend.php:767
  4. qtranxf_translate_metadata() htdocs/content/plugins/qtranslate-xt/qtranslate_frontend.php:843
  5. qtranxf_filter_usermeta() htdocs/cms/wp-includes/class-wp-hook.php:310
  6. WP_Hook->apply_filters() htdocs/cms/wp-includes/plugin.php:205
  7. apply_filters() htdocs/cms/wp-includes/meta.php:632
  8. get_metadata_raw() htdocs/cms/wp-includes/meta.php:571
  9. get_metadata() htdocs/cms/wp-includes/user.php:1159
 10. get_user_meta() htdocs/cms/wp-includes/class-wp-user.php:324
 11. WP_User->__get() htdocs/cms/wp-includes/l10n.php:109
 12. get_user_locale() htdocs/content/plugins/groups/lib/core/class-groups-controller.php:180
 13. Groups_Controller->get_mofile() htdocs/content/plugins/groups/lib/core/class-groups-controller.php:195
 14. Groups_Controller->load_textdomain_mofile() htdocs/cms/wp-includes/class-wp-hook.php:308
 15. WP_Hook->apply_filters() htdocs/cms/wp-includes/plugin.php:205
 16. apply_filters() htdocs/cms/wp-includes/l10n.php:759
 17. load_textdomain() htdocs/content/plugins/copy-the-code/classes/class-copy-the-code.php:98
 18. Copy_The_Code->localization_setup() htdocs/cms/wp-includes/class-wp-hook.php:308
 19. WP_Hook->apply_filters() htdocs/cms/wp-includes/class-wp-hook.php:332
 20. WP_Hook->do_action() htdocs/cms/wp-includes/plugin.php:517
 21. do_action() htdocs/cms/wp-settings.php:480
 22. require_once() htdocs/wp-config.php:32
 23. require_once() htdocs/cms/wp-load.php:55
 24. require_once() htdocs/cms/wp-blog-header.php:13
 25. require() htdocs/index.php:17

Which happens over here: https://github.com/qtranslate/qtranslate-xt/blob/master/qtranslate_utils.php#L389 This error happened on the latest version on PHP 8.1.

[ludiccc]

This can be fixed changing the line 389 on qtx_utils.php with

return !is_null($str) && preg_match( "/<!--:$lang_code-->|\[:$lang_code]|{:$lang_code}/im", $str );