[wmlunits] Index terrain types by the .string...

...instead of the .id field as the latter isn't unique right now.

data/tools/unit_tree/helpers.py

@@ -166,8 +166,8 @@ class WesnothList:
 
         n = 0
         for terrain in WML.get_all("terrain_type"):
-            tid = terrain.get_text_val("id")
-            self.terrain_lookup[tid] = terrain
+            tstring = terrain.get_text_val("string")
+            self.terrain_lookup[tstring] = terrain
             n += 1
         return n
 

data/tools/wmlunits

@@ -706,7 +706,8 @@ class HTMLOutput:
 
         terrains = self.wesnoth.terrain_lookup
         terrainlist = []
-        for tid, t in terrains.items():
+        for tstring, t in terrains.items():
+            tid = t.get_text_val("id")
             if tid in ["off_map", "fog", "shroud"]: continue
             if t.get_first("aliasof"): continue
             name = t.get_text_val("name")