Fix fatal error when CUSTOM_EMAIL_QUERY_FUNCTION returns void

[cnbhl]

Summary

• Adds null-safety check for the return value of CUSTOM_EMAIL_QUERY_FUNCTION in checkLoginAgainstIMAP()
• Prevents a fatal error (count(): Argument #1 must be of type Countable|array, null given) when custom auth plugins don't return an array

Background

Since 1.4.8, auth.php line 415 assigns the return value of CUSTOM_EMAIL_QUERY_FUNCTION directly to $emails:

$emails = call_user_func(CUSTOM_EMAIL_QUERY_FUNCTION, $username);

Custom auth plugins written for piler ≤ 1.4.4 (such as mailpiler-mailcow-integration) only modify the session and don't return the email array. This causes $emails to become null, leading to a fatal error on the subsequent count() / array_merge() calls.

Result: Users who authenticate via IMAP with a custom email query function see a blank page (HTTP 500) after login.

Fix

Store the return value in a temporary variable and only overwrite $emails if the result is a non-empty array:

$result = call_user_func(CUSTOM_EMAIL_QUERY_FUNCTION, $username);
if(is_array($result) && count($result) > 0) {
    $emails = $result;
}

This is backwards compatible — old plugins that modify the session directly will continue to work, and new plugins that return the array will also work.

Related

• Fixes CUSTOM_EMAIL_QUERY_FUNCTION return value required since 1.4.8 — breaks custom auth plugins #430
• Likely fixes [BUG] No mails visible on user level since upgrade (1.4.4 to 1.4.8 on debian 12) #330

🤖 Generated with Claude Code

[jsuto]

Thank you!