Attachment button to embed attachment not available when commenting during issue transition or comment edit

Summary

The attachment button is not available when commenting in the same transition where attachment is uploaded to the issue. The same happens when user is editing an existing comment.

Scenario 1, issue transition

Steps to Reproduce

1. Edit a screen to have attachment field and comment field
2. Associate the screen with a workflow
3. Transition the issue to the point where it will use the screen
4. Add an attachment and upon commenting the attachment button is not available to be selected

Expected Results

The attachment button is available and can be selected

Actual Results

No attachment button is available

Scenario 2, editing a comment

Steps to Reproduce

1. Add a comment to an issue
2. Edit the comment and click on the add attachment option

Expected Results

Browse attachment is displayed

Actual Results

Browse attachment is not displayed

Notes

• The attachment button in comments will be available if there are existing attachments in the issue before the transition.
• In Jira 8.20.x, the attachment button does show up, but after clicking it, it disappears again.

Workaround

1. Add attachment first, then in another screen add comment with embedded attachment.
2. Drag and drop attachments to the comment field (the attachment will be uploaded and embedded into the comment)
3. The Attachment button will only appear on a Transition screen when there are existing attachments in the ticket, however, there's no option to browse and upload the attachment by clicking on the "+ Browse" link from the drop-down of the Attachment button. Hence, the workaround is to add the system Attachments field to the transition screen.