Not sure if related to bug 55392.
IP user on it.wp reports what follows:
he edited https://it.wikipedia.org/w/index.php?title=Citt%C3%A0_d%27Italia&action=history multiple times.
First edit, an edit conflict notice came up.
He tried to solve that, but there were no actual differences. At that point, although he didn't save, he noticed his edit had already been saved in the history.
Second edit, nothing to report.
Third edit, same thing as the first one.
Firefox 28.0, Win7, Vector.
I didn't try to reproduce.