Bug: Issue with email attachment after upgrading from 4.6.1 to 4.6.2

[mihail-minkov]

PHP Version

8.3

CodeIgniter4 Version

4.6.2

CodeIgniter4 Installation Method

Composer (using codeigniter4/appstarter)

Which operating systems have you tested for this bug?

Windows

Which server did you use?

apache

Database

MySQL 8.0

What happened?

I was working on a function in my controller that previously worked without any issues. The function generates a PDF file and sends it as an attachment using the email library.

When it got to that part, the process failed showing this error:

ErrorException
Undefined array key "cid"

SYSTEMPATH\Email\Email.php at line 1311

1304             }
1305 
1306             $name = $attachment['name'][1] ?? basename($attachment['name'][0]);
1307             $body .= '--' . $boundary . $this->newline
1308                 . 'Content-Type: ' . $attachment['type'] . '; name="' . $name . '"' . $this->newline
1309                 . 'Content-Disposition: ' . $attachment['disposition'] . ';' . $this->newline
1310                 . 'Content-Transfer-Encoding: base64' . $this->newline
1311                 . ($attachment['cid'] === '' ? '' : 'Content-ID: <' . $attachment['cid'] . '>' . $this->newline)
1312                 . $this->newline
1313                 . $attachment['content'] . $this->newline;
1314         }
1315 
1316         // $name won't be set if no attachments were appended,
1317         // and therefore a boundary wouldn't be necessary
1318         if (isset($name)) {

Basically this line:

. ($attachment['cid'] === '' ? '' : 'Content-ID: <' . $attachment['cid'] . '>' . $this->newline)

My e-mail object is adding the attached file like this:

$email->attach(file_get_contents($filename), 'attachment', 'quote.pdf', 'application/pdf');

Steps to Reproduce

1. Make a new $email = \Config\Services::email(); object.
2. Attach a file using file_get_contents(...) as an attachment.
3. Send email.

Expected Output

I expect the e-mail to be sent in a regular manner.

Anything else?

The only thing I can think of is that I updated from PHP 8.1.30 to 8.3.22 just two days ago, so I haven't tested everything yet on 8.3, but this function used to work without any issues on 8.1 and as far as I know the email library hasn't been modified.

I suppose perhaps adding some conditions to the ['cid'] index check, in case it's not set.

[neznaika0]

Yes. There was a change. It is worth adding an isset() check to fix it. Can you send a PR?

-                . (empty($attachment['cid']) ? '' : 'Content-ID: <' . $attachment['cid'] . '>' . $this->newline)
+                . ($attachment['cid'] === '' ? '' : 'Content-ID: <' . $attachment['cid'] . '>' . $this->newline)

[michalsn]

It seems we missed this during refactoring. The fix is on the way.

In the meantime, as a temporary workaround, you can call the setAttachmentCID('quote.pdf') method after attach().