Let's say a user edited a post but it was not visible (as user didn't have edit privileges so edit needs to be approved or rejected by an edit privileged user).
Now before this edit gets approved, an another edit privileged user edits the post.
Now, how will this be handled? Will the edit of previous user be rejected automatically or it will be handled in some other way?
There are two cases here.
If there is a pending suggested edit on a post, another user cannot edit the post until it's rejected or approved.
If there are two different users editing at the same time, there will be an edit conflict and the suggested edit will be rejected by Community user.
In this case, the advantage goes to the user with edit privileges. Their edit will be shown and the suggested edit will be automatically rejected with the reason "This edit conflicted with a subsequent edit".
I'm not sure which one you are talking about. The answer is Reject if it's the second case. However, this doesn't effect the suggested edit ban because it's not the fault of user who suggested the edit.
Since once suggested-edit posted and system will show edit(1) button which opens the review, there is very less chance of happening this case. It happens when edit privileged user starts editing the same time to a user suggesting an edit. In that case, suggested edit will be rejected by Community ♦ user with the reason "This edit conflicted with a subsequent edit" but it doesn't count for automatic ban from suggesting-edit.
Visit How do suggested edits work? or Why does the Community ♦ user approve and reject edits? for detailed information:
A user with full edit privileges saves an edit over yours
If a user with full editing privileges for a post (including the original poster) begins editing the post at the same time as you, and they save their edit after you have already suggested it, then your suggested edit will be overridden in favor of their fully-privileged edit.
This is known in software as an optimistic lock. This is an edge case, and does not happen often because users with full privileges who try to edit a post after you submit your edit will be directed to your suggested edit instead. Thus, when one person starts editing a post, we do not need to lock everyone else out. While the UI attempts to avoid these situations (by prompting you with "an edit has been made to this post; click to load"), they do sometimes occur.
This sometimes appears strange to a viewer—as if Community ♦ has immediately rejected their edit, without warning, with no hesitation.
Do not be alarmed! This is just concurrent modification working its evil magic once again. This type of rejection will not be counted towards automated edit bans. Simply submit your edit again and it may actually be reviewed.
Another way this can occur is if a fully-privileged user makes an edit, then you suggest another edit right afterwards, and then the first user makes another edit during their 5-minute grace period. In that case, a new revision is not created, but your suggestion is still automatically rejected due to the edit conflict.
