Issue Summary

Copying and then pasting an image from the already existing image on the page will result in a broken image in edit mode when using https.

Environment

Confluence 6.15.4 running over HTTPS connection

Steps to Reproduce

1. Upload an image to an empty page
2. Copy the image
3. Paste the same image to the same page

Expected Results

The image will be displayed correctly.

Actual Results

Image is not displayed at all, and in the DOM of the page, we can see that new image uses incorrect URL (src of the image) to the image as it uses HTTP instead of HTTPS.

Notes

The issue is not observable if the Confluence instance uses HTTP instead of HTTPS connection.
The issue is also visible with reverse proxy.

Workaround

If instance uses a reverse proxy, make a rule to forward HTTP connection to https. That way the image will be resolved.
eg for Apache:

<VirtualHost *:80> 
Redirect permanent / https://www.yourdomain.com/ 
</VirtualHost>