[Freeciv-Dev] (PR#2789) Units sometimes remain displayed in fog of war

["Jason Short via RT" <rt@xxxxxxxxxxxxxx>]

[guest - Fri Jan 10 05:26:04 2003]:

> Sometimes, enemy units remain displayed in the fog of war. This is
> usually after a unit has attacked, or a ship has unloaded during the
> enemy move turn.  For instance, if an enemy ship is in the fog of war,
> but unloads a unit within my view range, the enemy ship remains visible.
>  If I move away from the enemy ship in my turn, it remains displayed in
> the fog of war square.
> 
> I'm using CVS from Jan 5, gtk2 client on RH8.  A savegame is available
> at http://kenn-michelle.ca:8080/freeciv/fog.sav.gz (should I attach
> savegames to here?.. they can be big).  Join as kenn.  Note area around
> Ottawa.  End turn.  Note the enemy ship next to Ottawa.  Move destroyer
> away from that area.  Wait a turn.  Move destroyer back to that area. 
> The enemy ship is still displayed, and you can even move on top of it,
> although it isn't actually there.

This is not a drawing bug.  It appears that the core client code
actually thinks that there's a ship at that location.  Very bizarre!

A secondary bug is that the enemy ship doesn't actually get animated
moving out of Ottowa.  This, I assume, is a drawing bug (or is it a
feature?).

As a side note, this is the kind of bug we will see more of with
delta-style packets.  Because the original information doesn't get
resent, there is no way for the client to correct any mistakes it may
have made in the meantime.

jason

P.S.  You can upload savegames to ftp://upload.sf.net/freeciv/incoming/,
although they tend to get clogged up.  Better is to send them to (IIRC)
comment@xxxxxxxxxxxxxx which will record them under the RT ticket but
won't forward them to anyone.