Inline image attachments broken with ActionMailer for Version 1.3.3

[robotbill]

I upgraded to 1.3.3 in an attempt to fix an issue where inline images were not rendering correctly in emails. However, after upgrading the images are now included, but as attachments, not inline. It works correctly in 1.2.16.

We're using Rails 7.2.2.1 and sending emails via ActionMailer. Our images are added to view using the Rails image_tag helper.

On 1.3.3 I see the following in the raw email (in 1.3.2 there are no parts for the attachments):

Content-Type: image/png; name="."
Content-Transfer-Encoding: base64
Content-Disposition: inline; filename="."
Content-Id: <.>

But in 1.2.16 I get:

Content-Type: image/png; name="67e342ab9e224_3211368-45@80354324-8dad-4ef5-a5fd-111fc025b1d0.mail"
Content-Transfer-Encoding: base64
Content-Disposition: inline; filename="67e342ab9e224_3211368-45@80354324-8dad-4ef5-a5fd-111fc025b1d0.mail"
Content-Id: <67e342ab9e224_3211368-45@80354324-8dad-4ef5-a5fd-111fc025b1d0.mail>

Previously #340 and #341

Thanks,
Joe

[chrisdrydenaltmetric]

Can confirm, attempted to upgrade to v1.3.4 but following a fix to #340 and #341 but still getting the same issue (from the Mailgun logs):

--accdc37932ae9bb8afa6b6498bd74db28e8b124922731ab9173996e4ed17
Content-Type: image/png; name="."
Content-Transfer-Encoding: base64
Content-Disposition: inline; filename="."
Content-Id: <.>

[alex-leb]

@robotbill this issue was fixed in v1.3.5. Please check if inline attachments work for you on the latest version.

[robotbill]

@alex-leb Thank you. We'll give it a try and let you know!

[robotbill]

Confirming that this is fixed for us now.