Added a failsafe for cases where the walker population randomly dies out

dungeonbattle/mapgeneration/randomwalk.py

@@ -66,6 +66,7 @@ class Generator:
             # next iteration of the main loop
             next_walker_pop = []
 
+            failsafe = choice(walkers)
             for walker in walkers:
                 if grid[walker.y][walker.x] == Tile.WALL:
                     count += 1
@@ -76,6 +77,10 @@ class Generator:
                 if random() > self.params["death_chance"]:
                     next_walker_pop.append(walker)
 
+            # we make sure to never kill all walkers
+            if next_walker_pop == []:
+                next_walker_pop.append(failsafe)
+
             # we use a second loop for spliting so we're not bothered by cases 
             # like a walker not spliting because we hit the population cap even
             # though the next one would have died and freed a place