WordPress Release: 4.1.33

TL;DR

WordPress 4.1.33 is primarily a maintenance release focused on modernizing the development infrastructure for the 4.1 branch. It updates build and test tools to support NodeJS 14.x, introduces Docker-based local development, transitions from TravisCI to GitHub Actions for automated testing, and includes an important security fix for PHPMailer attachment handling. This release ensures the 4.1 branch remains maintainable with modern development tools while receiving security updates as a courtesy.

Highlight of the Release

• Transition from TravisCI to GitHub Actions for automated testing
• Introduction of Docker-based local development environment
• Support for NodeJS 14.x in the 4.1 branch
• Security improvement in PHPMailer attachment handling

Migration Guide

Migration from TravisCI to GitHub Actions

If you were using TravisCI for testing WordPress 4.1 branch code:

1. TravisCI configuration has been removed in favor of GitHub Actions
2. All automated testing now runs through GitHub Actions workflows
3. Review the new workflow files in .github/workflows/ directory to understand the new testing process
4. Use the workflow_dispatch event to manually trigger test runs when needed

Using the Docker-based Development Environment

To use the new Docker-based local development environment:

1. Ensure Docker and Docker Compose are installed on your system
2. Navigate to the WordPress 4.1 branch directory
3. Follow the standard WordPress Docker environment setup instructions
4. The environment is now consistent with those used in newer WordPress branches

Upgrade Recommendations

This is primarily a maintenance release focused on development infrastructure rather than user-facing features or critical security fixes. However, it does include an improvement to PHPMailer attachment handling that enhances security.

For site administrators: If you're running WordPress 4.1.32, upgrading to 4.1.33 is recommended for the security improvement, though the impact is minimal for most sites.

For developers: If you're actively developing or contributing to the WordPress 4.1 branch, upgrading is strongly recommended to take advantage of the modernized development tools and testing infrastructure.

Note that WordPress 4.1 is a very old version (originally released in December 2014), and it's strongly recommended to upgrade to a current WordPress version for the latest features, performance improvements, and security updates.

Bug Fixes

No specific bug fixes were included in this release beyond the development infrastructure improvements.

New Features

Development Environment Improvements

• Docker-based Local Development: Introduced Docker-based local WordPress development environment to the 4.1 branch, making it consistent with newer WordPress versions
• NodeJS 14.x Support: Updated dependencies to support the latest LTS version of NodeJS (14.x)
• GitHub Actions Integration: Added workflow files required to run automated testing on GitHub Actions
• Workflow Improvements:
  • Added support for workflow_dispatch event to run tests on a schedule
  • Split single site and multisite tests into parallel jobs
  • Split slow tests into separate, parallel jobs for PHP <= 5.6
  • Improved branch and path scoping for GitHub Action workflows

Security Updates

PHPMailer Security Improvement

• Improved attachment handling in PHPMailer to address potential security issues
• This change was partially merged from revision [50799] to enhance email attachment security

Performance Improvements

Testing Performance Improvements

• Parallel Test Execution: Split single site and multisite tests into parallel jobs
• Optimized Test Workflows: Separated slow tests into dedicated parallel jobs for PHP <= 5.6
• Improved Test Reliability: Enhanced skipTestOnTimeout() to handle more types of timeouts in HTTP tests

Impact Summary

WordPress 4.1.33 represents a significant modernization of the development infrastructure for the 4.1 branch, which continues to receive security updates as a courtesy despite being an older version. The primary impact is on developers and contributors working with this branch, who now have access to modern tools like Docker-based local development and GitHub Actions for testing.

The transition from TravisCI to GitHub Actions completes a process that began months earlier, bringing the 4.1 branch in line with newer WordPress versions in terms of development workflow. The addition of NodeJS 14.x support enables the use of current development dependencies across all maintained WordPress branches.

For end users and site administrators, the impact is minimal, with the only user-facing change being an improvement to email attachment handling in PHPMailer. This release contains no functional changes to WordPress itself, focusing instead on maintaining the development infrastructure that allows the WordPress team to continue providing security updates to this older branch.