[Freeciv-Dev] File save format: rivers?

[Miguel Farah <miguel@xxxxx>]

I've finally got off my lazy ass to do the modifications my map2gif
script requires to properly handle the rivers in V2 maps. I looked into
saved files, and I found that the rivers are designated by a '2' in the
n0?? lines. Looking a bit more, I noticed that the possible values
indicated:

0: regular terrain
1: special 2 (oil, whale, fruit, etc.)
2: river
3: special 2 + river
4: as 0 + farmland
5: as 1 + farmland
6: as 2 + farmland
7: as 3 + farmland
8: as 0 + airbase
9: as 1 + airbase

So, what would '10' (river + airbase) upto '15' (all the goodies) be
written as in the .sav? Where is special 1? What I really need is to
know that the "bit 2" is indeed what indicates if a river is present in
a given square. Am I right?