Confirm Navigation dialog on post.php when no changes have been made

[c3mdigital]

To reproduce bug:

Go to any post and click update. Click view post or navigate away from post.php

You will get the confirm navigation javascript alert message.

I can't reproduce this on trunk.
Tried different scenarios, but only got the message when I had made changes without saving, as expected.

Replying to TobiasBg:

I can't reproduce this on trunk.
Tried different scenarios, but only got the message when I had made changes without saving, as expected.

I've been doing some more testing and this is only happening on posts that have an inserted image in visual mode.

Replying to c3mdigital:

this is only happening on posts that have an inserted image in visual mode.

Confirmed.

Ah, yes, for that case I can also confirm it.
Clicking "Update" is not even necessary. Just opening a post/page with an image results in that message when navigating away without doing changes, but only when the "Visual" editor is used.

Can someone confirm this is not the case in 3.4? Also, there were two distinct changes here that could have caused this: either r21545 (TinyMCE 3.5.6) or the more recent media changes.

Introduced in [22012].

I did a git bisect, and it says [22120] was the introduction of the bug.

Need to be on Visual tab.

• [22012] is where it broke when a single image is embedded.
• [22120] is where it broke when an image gallery is embedded.

Related: #22266

Duplicate of #22266.