Add automatic retry mechanism for HTTP requests

[Copilot]

Implementation Complete: Add automatic retries to download paths

Properly rebased onto latest main branch using git rebase

Rebase Details

• Base commit: 5aa34009 (Merge pull request Fix new PHPStan errors #6163 from wp-cli/fix/phpstan-errors)
• Clean rebase with proper conflict resolution
• Integrated latest SSL error handling improvements from main
• All commits cleanly applied on top of main

Implementation Summary

Successfully implemented automatic retry mechanism for HTTP requests in WP-CLI with a hardcoded 3 retry threshold.

Key Features

1. Hardcoded 3 retries - Simple, non-configurable retry mechanism
2. Smart retry logic - Only retries on transient network errors (timeouts, connection issues)
3. Exponential backoff - Uses 1s, 2s, 4s, 8s, 10s (max) delays between retries
4. Clear debug logging - Shows retry 1/3, 2/3, 3/3 when --debug=http is enabled
5. Backward compatible - No breaking changes, works transparently with existing code
6. PHP 8.5+ compatible - Handles curl_close deprecation
7. Properly integrated with main - Clean rebase onto latest main with improved SSL error handling

Transient Errors Handled

• CURLE_OPERATION_TIMEDOUT (28) - Operation timeout
• CURLE_COULDNT_RESOLVE_HOST (6) - Couldn't resolve host
• CURLE_COULDNT_CONNECT (7) - Failed to connect
• CURLE_PARTIAL_FILE (18) - Partial file transfer
• CURLE_GOT_NOTHING (52) - Server returned nothing
• CURLE_SEND_ERROR (55) - Send error
• CURLE_RECV_ERROR (56) - Receive error

Files Changed

• php/utils.php - Implemented retry logic and helper function with proper integration
• tests/UtilsTest.php - Added unit test for transient error detection

Benefits

• Improved reliability for downloads (themes, plugins, core, language files)
• Better automated test stability
• Reduced impact of transient network failures

Original prompt

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This section details on the original issue you should resolve

<issue_title>Add automatic retries to download paths</issue_title>
<issue_description>For operations like downloading a theme or a language file, or latest Core code, we should have an automatic retry mechanism with a configurable threshold (defaulting to 3 as a good compromise).

This would not only make general scripting with WP-CLI more reliable but also drastically increase the reliability of our automated tests, which constantly fail due to random timeouts when doing downloads.</issue_description>

Comments on the Issue (you are @copilot in this section)

• Fixes Add automatic retries to download paths #4894

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[codecov]

Codecov Report

❌ Patch coverage is 78.00000% with 11 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
php/utils.php	78.00%	11 Missing ⚠️

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[Copilot]

Pull request overview

This PR implements an automatic retry mechanism for HTTP requests in WP-CLI to improve reliability when downloading themes, plugins, core files, and language packs. The implementation adds exponential backoff retry logic that triggers on transient network failures (timeouts, connection issues) with a hardcoded limit of 3 retries.

Key changes:

• Added is_transient_http_error() helper function to identify retryable network errors
• Modified http_request() to automatically retry on transient failures with exponential backoff (1s, 2s, 4s delays)
• Added basic test coverage for transient error detection

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
php/utils.php	Implements retry loop with exponential backoff in http_request() and adds is_transient_http_error() helper to detect retryable curl errors
tests/UtilsTest.php	Adds test for is_transient_http_error() function with timeout error scenario and PHP 8.5+ curl_close handling

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