Ground units: Avoid stepping onto dangerous/deep floor

core/src/mindustry/ai/Pathfinder.java

@@ -292,7 +292,7 @@ public class Pathfinder implements Runnable{
             }
         }
 
-        if(current == null || tl == impassable) return tile;
+        if(current == null || tl == impassable || (path.cost == costTypes.items[costGround] && current.dangerous() && !tile.dangerous())) return tile;
 
         return current;
     }

core/src/mindustry/world/Tile.java

@@ -378,6 +378,11 @@ public class Tile implements Position, QuadTreeObject, Displayable{
         return block.destructible || block.breakable || block.update;
     }
 
+    /** @return whether the floor on this tile deals damage or can be drowned on. */
+    public boolean dangerous(){
+        return !block.solid && (floor.isDeep() || floor.damageTaken > 0);
+    }
+
     /**
      * Iterates through the list of all tiles linked to this multiblock, or just itself if it's not a multiblock.
      * The result contains all linked tiles, including this tile itself.