Silence ini_set() in wp_debug_mode() if WP_DEBUG is off

[SergeyBiryukov]

In [24564], we've added ini_set( 'display_errors', 0 ) for XML-RPC requests.

In [36571], we did the same for AJAX requests. Apparently this caused issues on sites where ini_set() has been disabled for security reasons, see comment:24:ticket:26262.

As this line fires regardless of WP_DEBUG value and can lead to unexpected errors in production, we should add error suppression here (at least if WP_DEBUG is disabled), as we already do in every other instance of ini_set() in core.

[avagoldin]

#36692
Maybe ini_set( 'display_errors', 0 ); only if WP_DEBUG is false?

[adamsilverstein]

Replying to avagoldin:

#36692
Maybe ini_set( 'display_errors', 0 ); only if WP_DEBUG is false?

I agree with this suggestion: logging can be useful here to debug a failing ajax or xml-rpc callback. Even though displaying errors breaks the calls, it also exposes the errors more directly for developers who may not have file/log file access. If I had WP_DEBUG true I would expect to see errors regardless of the context.

As a side note, it would be good to check wp-api calls to see if we follow the same logic of suppressing errors there.

[avagoldin]

Added WP_DEBUG check.

[avagoldin]

Replying to adamsilverstein:

I agree with this suggestion: logging can be useful here to debug a failing ajax or xml-rpc callback. Even though displaying errors breaks the calls, it also exposes the errors more directly for developers who may not have file/log file access. If I had WP_DEBUG true I would expect to see errors regardless of the context.

I added a patch with a check for WP_DEBUG.

As a side note, it would be good to check wp-api calls to see if we follow the same logic of suppressing errors there.

if ( ! WP_DEBUG && ( defined( 'XMLRPC_REQUEST' ) || defined( 'REST_REQUEST' ) || ( defined( 'DOING_AJAX' ) && DOING_AJAX ) ) ) {
	@ini_set( 'display_errors', 0 );
}

defined( 'REST_REQUEST' ) is in the test if it is what you mean.

[ocean90]

#36777 was marked as a duplicate.

[ocean90]

For 4.5.3 we should go with 36708.patch​. Changing the value based on WP_DEBUG should be handled in a new ticket.

[swissspidy]

In 37448:

Bootstrap/Load: Silence ini_set() in wp_debug_mode().

Props SergeyBiryukov.
Fixes #36708 for trunk.

[ocean90]

In 37451:

Bootstrap/Load: Silence ini_set() in wp_debug_mode().

Merge of [37448] to the 4.5 branch.

Props SergeyBiryukov.
Fixes #36708.