The stranger who never moved

We said we would write here when the public server opened. It opened on 10 October, and on the morning of the 11th it had its first proper crowd: three of us, and a fourth player nobody recognised.

The fourth player never moved and never said a word. Shortly after eight, about forty-five NPCs around us stopped where they stood. One of them stayed frozen, in three different games, for thirteen minutes.

Where the NPCs went

Each NPC runs in exactly one game, its owner's; everyone else sees a copy. When an owner lets an NPC go, the server hands it to the first other player in range. That morning, the first player in range was the stranger.

The stranger's game had not sent anything for minutes. It never ran the NPCs it was given, and as long as they had an owner on paper, nobody else could take them over. So they stood there.

Players who have gone quiet now come last when the server hands NPCs out.

Who it was

One of us. A friend's game had connected early, under the name of the character it loaded at start. Later it connected again, and the networking library opened the new connection on top of the old one without closing it. The old one lived on inside their game, answering the server's "still there?" and sending nothing else. To the server, that was a second player under another name, right to the end of the session.

Now a new connection closes the old one first. And if the character you load is not the one you connected with, the game connects again under the right name.

Two more things that morning showed us

Copies of players at doors. A copy the mod deleted while the game was still holding it stayed in its cell, marked deleted, and the game rebuilt it the next time that cell loaded. The three logs from that morning held 10, 23 and 13 of them. A deleted copy now gets no body to rebuild.

Bandits that multiplied. Later that morning a friend reconnected five times in half an hour and came back each time to more bandits. The copies standing in their game when they left were sent to the server as new bandits when they came back, while the server sent the originals again. Copies left standing at a disconnect are now cleared when you connect again.

And a dead body can now be dragged by anyone who grabs it. Before, only someone in the same party could, and that morning nobody was in one.

Status

All of it is in 1.9.3, released the same day. The public server runs 1.9.3.