Impassable ambush

[bb]

Seed 4036137132 on small ambush with 2 players, results in a map where the players cannot reach each other. This might happen on other seeds too.

See the (A21) replay below (extend empty turns if wanted):

start {"settings":{"PlayerData":[{"Name":"bb","Civ":"brit","Color":{"r":46,"g":46,"b":200},"AI":"","AIDiff":3,"Team":-1},{"Name":"Ashoka the Great","Civ":"maur","Color":{"r":150,"g":20,"b":20},"AI":"petra","AIDiff":5,"Team":-1}],"CheatsEnabled":true,"CircularMap":true,"Size":192,"GameType":"conquest","VictoryScripts":["scripts/TriggerHelper.js","scripts/ConquestCommon.js","scripts/Conquest.js"],"WonderDuration":20,"PopulationCap":300,"Ceasefire":0,"StartingResources":300,"Name":"Ambush","Script":"ambush.js","Description":"High bluffs overlook the terrain below. Bountiful resources await on the cliffs, but beware of enemies planning an ambush.","BaseTerrain":["medit_sea_depths"],"BaseHeight":2,"Preview":"ambush.png","RatingEnabled":false,"TriggerScripts":["scripts/TriggerHelper.js","scripts/ConquestCommon.js","scripts/Conquest.js"],"mapType":"random","Seed":4036137132,"AISeed":3904037722},"map":"maps/random/ambush","mapType":"random","mapPath":"maps/random/","mapFilter":"default","matchID":"B022775545BC58B6","gameSpeed":1,"script":"ambush.js","timestamp":"1485522372","engine_version":"0.0.21","mods":["mod","public","user"]}
turn 0 200
end
turn 1 200
end
turn 2 200
end
turn 3 200
end
turn 4 200
end
turn 5 200
end
turn 6 200
end
turn 7 200
end
turn 8 200
end
turn 9 200
end

Bug reproducible in atlas in current svn.

[elexis]

I would have said it's fixed in #4993, but it likely isn't fixed in all situations.

What needs to happen is ensuring that a bluff never goes from one map border to the other.