Attachment icon function is broken

Summary

Attachment links is not showing after clicking at the attachment icon from "Add flag and comment" pop up dialog. For example:

Environment

• JIRA 7.3.8
• Chrome, Firefox and IE 11 browser

Steps to Reproduce

Scenario 1

1. Open any Agile board.
2. Click on any issue to display the issue details at the right of the screen.
3. Attach a file.
4. Click on ... button and select "Add flag and comment" button.
5. Click Attachment icon.

Scenario 2

1. Edit Comment from the issue detail at the right of the screen.
2. Click Attachment icon.
3. You can't see the list of the attachment links

Scenario 3 (in Firefox)

1. Click Comment from issue screen.
2. Click Browse and select a file, we will see the attachment icon broken:
   
   
3. It doesn't happen after added the comment.
   

Expected Results

JIRA should display any attachment links after click on the attachment icon.

Actual Results

JIRA is not display anything after clicking the attachment icon.

Notes

The reason why user attach a file at first is due to the Edit Comment does not show the Browse option in the Attachment Option bug.

Workaround

Link the attachment in the comment by using our attachment text formatting via Text mode:

!attachment.png!
!attachment.png|thumbnail!