Code issues with set_time_limit

[madpeter]

file: wp-admin\includes\ajax-actions.php
function: wp_ajax_get_revision_diffs
line: 3425
Issue: no time limit set
Suggestion: set value to 120

file: wp-includes\class-pop3.php
function: __construct
line: 63
Issue: timeout value is not tested and can be set to 9999999 or a negitive value that acts the same as 0
Suggestion: Force a range for the value (1 to 120)

[SergeyBiryukov]

Hi there, welcome to WordPress Trac! Thanks for the report.

• The set_time_limit( 0 ) instance in wp_ajax_get_revision_diffs() was introduced in [24707] / #24757. Could you clarify why the value should be changed to 120?
• Please note that class-pop3.php is a part of the PHPMailer external library, any changes to its files should be submitted upstream: ​https://github.com/PHPMailer/PHPMailer.

[madpeter]

The set_time_limit( 0 ) instance in wp_ajax_get_revision_diffs() was introduced in [24707] / #24757. Could you clarify why the value should be changed to 120?

if a badly coded plugin calls wp_ajax_get_revision_diffs but does not call set_time_limit itself and then it hangs due to a bug it can hold php active and not free up memory or worse use a while loop to hog cpu time.

but having a known limit for all set_time_limit calls it can help highlight issues with poorly coded plugins as it will create php time out warnings.

class-pop3.php
I will need to open a new ticket as wordpresses copy of phpmailer to far out of date.

[pbearne]

Fixed in [24707]

Closing ticket

[desrosj]

Reopening for another look.

@pbearne was [24707] the changeset you meant to share? That commit was 11 years ago but this ticket was only opened 5 years ago.

[pbearne]

Maybe not

Lets see if we can sort this

Paul

[SergeyBiryukov]

This appears to be the only instance of set_time_limit( 0 ) in core, i.e. removing the timeout limit completely.

Other instances have a reasonable limit instead, e.g. set_time_limit( 5 * MINUTE_IN_SECONDS ).

Looking at #24757 again, I think we could do the same here to avoid hanging processes.

[lovesoni1999]

Code issues with set_time_limit fix

Code issues with set_time_limit for ticket: 49291

Trac ticket: https://core.trac.wordpress.org/ticket/49291

I have set limit for timeout to 120 for smooth workflow of ajax and POP3 email

[lovesoni1999]

Created pull request in trunk

​https://github.com/WordPress/wordpress-develop/pull/7638

[SergeyBiryukov]

In 59288:

Revisions: Set PHP time limit when generating revision diffs vis Ajax.

This aims to avoid hanging PHP processes if a plugin inadvertently attempts to request a large number of revision diffs.

Follow-up to [24520], [24707], [59039].

Props madpeter, lovesoni1999, debarghyabanerjee, pbearne, desrosj, SergeyBiryukov.
Fixes #49291.

Thanks for the PR! Merged in r59288.