Comment 5 for bug 1216305

I disabled the ability to construct ports on enemy territory in rev. 6739. Further I fixed a bug where a player was able to construct a port from the expedition ship, where the player would not have been able to build it because of a too close player infrastructure (e.g. flag on a position that disallows the placement of the ports base_flag).

Anyway, I disagree concerning the disallow of port placement in general if terrain is already conquered by you and the player is only blocked from constructing a port because of some natural immovables that are blocking the space. The main reasons why the ship should still be able to construct a port at said places:

* The need to allow the placement of ports on places in terrain, where normal buildhelp would not allow to place a port, is a fundamental feature legitimated through at least two facts:
1. The tree spreading feature (I know you (SirVer) do not like it , however we decided in the community to keep it and still have it ;) ) might lead to blocked port buildspaces on islands that won't be settle-able without said port space.
2. Once the "clear enemy territory" feature is implemented in some way, there *must* be a way to find blocked port spaces - and not just those that are used for enemy ports, but as well those that are blocked by a tree (else the player could build up a "security wall of trees" with some foresters) or any other enemy building

* If a possible port space is blocked - no matter if inside or outside already owned territory - the behaviour of the expedition ship should be the same for owned as well as unowned territory - e.g. think about a map with long rivers and port spaces just directly face to face on each side of the river. Once a player conquers the territory near the port on one side of the river, builds a port and a shipyard and finally starts an expedition - the other side of the river is likely already (and even if only partly) conquered by the player (maybe even the conquer range of the port is enough) - so in case the port space is blocked by whatever immovable, it is now unusable for the player - although it would have been usable if the player had send out an expedition before reaching the part of the land.

I agree though, that the behaviour itself is a bit counter intuitive, therefore my idea would be to add a new message shown ocne a player clicks on the "construct port" button of the expedition ship and the area is blocked by some immovables - maybe something like "for the port construction to happen, we first need to clear the port space area. If you agree to do so, all resources that could be harvested out of those trees and other objects will be lost."

Or to go even further: We could add a forester and a stonemason to the expedition to explain the behaviour.

My point simply is: There should not be a special treatment of "already owned but blocked by immovables area"