Freeciv

The code (in server/maphand.c:is_claimable_ocean()) that allows a narrow bay (water tile with no more than two other adjacent water tiles and only a single adjacent continent) to be claimed by border sources from the surrounding continent erroneously treats oceanic border sources as being from that continent. This appears to be a holdover from a previous attempted bugfix that ended up being ultimately solved in a different way.

In the supplied rulesets, this is only relevant when playing with the Alien World ruleset and acquiring an ocean city (through conquest, diplomacy or map editing) before unlocking the respective technology (which gives Claim_Ocean and makes it all moot).