Title: mbstring.func_overload and PHP Warning
Last modified: August 21, 2016

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# mbstring.func_overload and PHP Warning

 *  Resolved [EliW](https://wordpress.org/support/users/eliw/)
 * (@eliw)
 * [12 years, 11 months ago](https://wordpress.org/support/topic/mbstringfunc_overload-and-php-warning/)
 * Hello, so I’d like to get some confirmation on something.
 * I recently migrated a bunch of existing WordPress installs to a new host. The
   new host I setup fully modern, which included latest PHP (5.4.16) and all the
   typical default configuration that I would do.
 * This included setting mbstring.func_overload = 7 — so that all UTF-8 was properly
   handled.
 * However, immediately after migration, my error log started filling with these
   errors:
 *     ```
       [12-Jun-2013 19:41:02 UTC] PHP Warning:  mb_stripos(): Empty delimiter in /[....]/wp-includes/functions.php on line 658
       [12-Jun-2013 19:41:02 UTC] PHP Warning:  mb_stripos(): Empty delimiter in /[....]/wp-includes/functions.php on line 661
       ```
   
 * After doing a bit of searching, I ran into this old thread:
    [http://wordpress.org/support/topic/php-warning-mb_stripos-empty-delimiter-caused-by-wp-cronphp?replies=19](http://wordpress.org/support/topic/php-warning-mb_stripos-empty-delimiter-caused-by-wp-cronphp?replies=19)
 * Thing is … from reading that thread, and from playing around. I realized that
   the mbstring.func_overload seemed to be the issue. I checked and the old server,
   in fact, had it set to 0
 * I changed mine on the new server to 0 … and it INSTANTLY stopped having issues.
 * But now that begs a new question:
 * “Can this be right?”. I would assume (especially after hearing Nacin speak at
   php[tek] 2013, in his keynote, about how WordPress is designed to just ‘always
   work, no matter what the PHP config) …
 * I would assume that WordPress would work fine whether mbstring was on, or off.
 * I personally don’t want mbstring turned off, because I have other scripts/websites
   on that server that should have the mbstring on.
 * So this is truly a bug in WordPress now that should be filed? That it should 
   work correctly regardless of whether func_overload is on?

Viewing 5 replies - 1 through 5 (of 5 total)

 *  [Shaun Scovil](https://wordpress.org/support/users/sscovil/)
 * (@sscovil)
 * [12 years, 11 months ago](https://wordpress.org/support/topic/mbstringfunc_overload-and-php-warning/#post-3837216)
 * Where is your `mbstring.func_overload` being set? It [can only be set from php.ini](http://www.php.net/manual/en/configuration.changes.modes.php)(
   or httpd.conf), and not at runtime.
 * Hope that is helpful…
 *  [Andrew Nacin](https://wordpress.org/support/users/nacin/)
 * (@nacin)
 * [12 years, 11 months ago](https://wordpress.org/support/topic/mbstringfunc_overload-and-php-warning/#post-3837279)
 * This is indeed a bug in WordPress — but it doesn’t actually have to do with mbstring.
 * Here’s the bug report: [http://core.trac.wordpress.org/ticket/23284](http://core.trac.wordpress.org/ticket/23284).
   I’ll be working on it this week and it’ll make it into the next version of WordPress.
 *  Thread Starter [EliW](https://wordpress.org/support/users/eliw/)
 * (@eliw)
 * [12 years, 11 months ago](https://wordpress.org/support/topic/mbstringfunc_overload-and-php-warning/#post-3837375)
 * Shaun, yes, it was in php.ini
 * And Nacin … ha! So I didn’t even notice that the order on those methods was wrong.
   Everything I found when googling the error, was pointing to func_overload.
 * And in fact setting func_overload to 0 … stopped the errors. That’s weird though.
 * I’m guessing (haven’t looked at core) but that mb_stripos will complain about
   an empty delimiter, but stripos just barges ahead?.
 * Thanks for the link to the bug report.
 *  Thread Starter [EliW](https://wordpress.org/support/users/eliw/)
 * (@eliw)
 * [12 years, 11 months ago](https://wordpress.org/support/topic/mbstringfunc_overload-and-php-warning/#post-3837377)
 * Marking as resolved.
 *  [Andrew Nacin](https://wordpress.org/support/users/nacin/)
 * (@nacin)
 * [12 years, 8 months ago](https://wordpress.org/support/topic/mbstringfunc_overload-and-php-warning/#post-3837608)
 * Follow-up: [http://core.trac.wordpress.org/ticket/25259](http://core.trac.wordpress.org/ticket/25259).

Viewing 5 replies - 1 through 5 (of 5 total)

The topic ‘mbstring.func_overload and PHP Warning’ is closed to new replies.

## Tags

 * [mbstring](https://wordpress.org/support/topic-tag/mbstring/)
 * [php](https://wordpress.org/support/topic-tag/php/)
 * [warning](https://wordpress.org/support/topic-tag/warning/)

 * In: [Fixing WordPress](https://wordpress.org/support/forum/how-to-and-troubleshooting/)
 * 5 replies
 * 3 participants
 * Last reply from: [Andrew Nacin](https://wordpress.org/support/users/nacin/)
 * Last activity: [12 years, 8 months ago](https://wordpress.org/support/topic/mbstringfunc_overload-and-php-warning/#post-3837608)
 * Status: resolved

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