update: polygonize MLS objects

server/map/get_relation.py

 import geopandas as gpd
-from shapely.geometry import Polygon, LineString
+from shapely.geometry import Polygon, LineString, MultiLineString
 from shapely.ops import linemerge, unary_union, polygonize
-import matplotlib.pyplot as plt
-import random
 import json
 import os
 
@@ -84,17 +82,17 @@ def create_grid(poly: Polygon, cell_size):
 
 
 def combine_grid_with_poly(polygon, grid):
-    # Create an empty list to store tiles intersecting the polygon
     intersecting_tiles = []
 
-    # Iterate through each grid line
     for line in grid:
-        # Check if the line intersects with the polygon
         if line.intersects(polygon):
-            # If the line intersects, find the intersection points
             intersection = line.intersection(polygon)
-            # Add each line to the list
-            intersecting_tiles.append(intersection)
+            # Check if intersection is a MultiLineString
+            if isinstance(intersection, MultiLineString):
+                # Extend the intersecting tiles with the polygonized results
+                intersecting_tiles.extend(list(polygonize(intersection)))
+            else:
+                intersecting_tiles.append(intersection)
 
     return intersecting_tiles