? is the ID of the post.
Pressing "Save Edits" without changing the textbox on a post that has "Edit (1)", will reject the edit by Community ♦
It's intended behavior that a concurrent edit by someone with the edit privilege instantly rejects a pending suggested edit with Community as the rejection user. This often happens accidentally when an editor with the edit privilege starts before the suggested edit is submitted and submits his edit after the suggested edit is submitted.
In such accidental cases, a revision by the user who caused the rejection appears in the post history. This revision could end up being trivial: even if a non-trivial edit was enforced in this case, the editor could change his mind during the 5-minute grace window. (It used to be that in this case the trivial revision wouldn't be shown, but that is no longer the case).
While we're on that topic, when I stumble upon a post with a pending suggested edit and I've used up my daily quota, I'd like to be able to choose to improve rather than reject that pending edit. The daily quota should block access to the queue but not prevent acting on a suggested edit that I find organically, or at least not prevent me from improving or reject-and-improving.
This has since changed to being status-completed.
The problem occurred because there was no check when loading a post's editor form to see if there was a pending suggested edit - save for a single client-side check when a post was loaded.
Per this staff post, there's now a server-side check for a pending edit suggestion when loading a post's editor form, regardless of how it's loaded: one will be directed to review the pending edit first.
As @Sonic notes, this has been fixed now. Except that there is another related situation. I'll post it here since it has some legitimate uses: when you accidentally approved a suggested edit and want to make sure no other reviewers make that mistake. The workaround is a little convoluted since you need the Stack Exchange API to do so, and you need write access. You can either inspect the traffic from the official Stack Exchange Android app (if you still have it) with a tool like mitmproxy or generate your own one.
For science, I suggested an edit here and approved it. I then submitted an edit (with exactly the same Markdown, but that isn't necessary) via this API documentation page (there's an equivalent one for questions):
(key and access token were filled but I've blanked them out) and as you can see from the review item, it was rejected because of the edit conflict.