Bug: upgrader_pre_download() strict bool type hint causes fatal TypeError with other plugins

[marcusquinn]

Summary

Addon_Repository::upgrader_pre_download() in inc/class-addon-repository.php:152 declares a strict bool $reply type hint:

public function upgrader_pre_download(bool $reply, $package, \WP_Upgrader $upgrader, $hook_extra) {

The WordPress upgrader_pre_download filter can legitimately pass WP_Error or string (file path) values through the callback chain — not just bool. When any earlier-priority filter returns WP_Error, this method throws a fatal TypeError.

Steps to Reproduce

1. Install Ultimate Multisite on a WordPress Multisite
2. Install any plugin that hooks upgrader_pre_download and may return WP_Error (e.g., Kadence Blocks Pro via StellarWP Uplink, WooCommerce Helper, GPLVault)
3. Attempt to update any plugin via WP-CLI or the admin UI

Expected Behavior

The filter callback should accept any value that WordPress core may pass through the filter chain, including WP_Error and string.

Actual Behavior

Fatal error:

Fatal error: Uncaught TypeError: WP_Ultimo\Addon_Repository::upgrader_pre_download(): 
Argument #1 ($reply) must be of type bool, WP_Error given

This crashes the entire update process.

Suggested Fix

Remove the bool type hint from $reply, or accept mixed and handle non-bool values:

// Option 1: Remove type hint (matches WordPress core's filter signature)
public function upgrader_pre_download($reply, $package, \WP_Upgrader $upgrader, $hook_extra) {
    if (!is_bool($reply)) {
        return $reply; // Pass through non-bool values from other filters
    }
    // ... existing logic
}

// Option 2: Accept mixed and guard
public function upgrader_pre_download(mixed $reply, $package, \WP_Upgrader $upgrader, $hook_extra) {
    if ($reply !== false) {
        return $reply;
    }
    // ... existing logic
}

Environment

• WordPress 6.7+
• PHP 8.1+
• Ultimate Multisite (latest from GitHub)
• Conflicting plugins: Kadence Blocks Pro (StellarWP Uplink), GPLVault Updater, WooCommerce

[superdav42]

Fixed in PR #376 (merged commit c6b2f8c).

What was changed: Removed the strict bool type hint from upgrader_pre_download($reply, ...) in inc/class-addon-repository.php and added an is_bool() guard that passes through any non-bool value unchanged.

This matches WordPress core's filter signature and prevents the fatal TypeError when plugins like Kadence Blocks Pro, GPLVault, or WooCommerce Helper return a WP_Error or string from an earlier-priority upgrader_pre_download filter hook.