WordPress Release: 4.4.12

TL;DR

WordPress 4.4.12 is a maintenance release that addresses two important issues: a bug in the PHPUnit testing framework and the restoration of numbered placeholders in wpdb::prepare(). This release ensures backward compatibility for plugins and themes that rely on numbered placeholders in database queries, while also improving the testing infrastructure for developers.

Highlight of the Release

• Restored support for numbered placeholders in wpdb::prepare() database queries
• Fixed PHPUnit test issues with proper message argument handling
• Added extra validation for database query preparation

Migration Guide

No migration is required for this release. The changes are backward compatible and designed to maintain functionality for existing code.

If you were affected by the previous removal of numbered placeholders in wpdb::prepare(), this release will restore that functionality, allowing your code to work as expected again without modifications.

Upgrade Recommendations

This is a recommended upgrade for all WordPress 4.4 users, especially for sites running plugins or themes that may use numbered placeholders in database queries. The release restores backward compatibility while improving code safety.

As always with any WordPress update, it's recommended to backup your site before upgrading.

Bug Fixes

Database Query Preparation Fix

Restored support for numbered placeholders in wpdb::prepare(). A previous update (in [41496]) had removed support for these placeholders, which despite being undocumented, were commonly used in many plugins and themes. This fix ensures backward compatibility for existing code while also adding extra validation to ensure the correct number of arguments are passed to the function based on the number of placeholders.

PHPUnit Testing Framework Fix

Fixed an issue in the WordPress testing framework where the $message argument wasn't being correctly passed to WP_UnitTestCase::setExpectedException() in specific test cases (Tests_Ajax_CompressionTest::test_logged_out() and Tests_Ajax_TagSearch::test_no_results()). This issue had gone unnoticed because PHPUnit 6.4.1 and earlier versions ignored the '0' value.

New Features

No new features were added in this maintenance release. The focus was on fixing bugs and maintaining compatibility.

Security Updates

No security fixes were explicitly mentioned in this release.

Performance Improvements

No specific performance improvements were included in this release.

Impact Summary

WordPress 4.4.12 is primarily a compatibility and bug fix release that addresses two specific issues:

1. It restores support for numbered placeholders in wpdb::prepare(), which had been removed in a previous update. This change is significant because many plugins and themes relied on this undocumented but widely used feature. The restoration ensures backward compatibility while also adding safety checks to validate the correct number of arguments.

2. It fixes an issue in the WordPress testing framework related to how message arguments are passed to exception handling in PHPUnit tests.

These changes maintain WordPress's commitment to backward compatibility while improving the robustness of the codebase. Site administrators should experience improved stability, particularly if their sites use plugins that rely on numbered placeholders in database queries.