AssertionError in construct_intersection()

[glennmatthews]

> bin/aagen -s 522492647 -r 10
....
----------Step 10----------
Rolling for passage continuation from <Connection 90: Open at (90, 10, 95, 15) to <Direction: southeast>>
16  Passage enters a chamber
Generating a random room...
Rolling shape and size for a Chamber (d20)
3   A 20x20 Chamber
Generating number of exits...
3   No larger than 600 square feet, so it has 1 exit(s)
Generating exit location...
8   Forward and right (south)
Checking passage width...
10  10 feet wide
WARNING:shapely.geos:Self-intersection at or near point 100 0
Generating exit direction for a passage...
20  The passage goes 45 degrees right (southwest), or if that doesn't work, 45 degrees left (southeast)
Traceback (most recent call last):
  File "bin/aagen", line 127, in <module>
    main()
  File "bin/aagen", line 73, in main
    dungeon_generator.step()
  File "/Users/glmatthe/Documents/Personal/AAGen/aagen/generator.py", line 1005, in step
    self.continue_passage(connection)
  File "/Users/glmatthe/Documents/Personal/AAGen/aagen/generator.py", line 131, in continue_passage
    self.generate_room(Region.CHAMBER, connection)
  File "/Users/glmatthe/Documents/Personal/AAGen/aagen/generator.py", line 462, in generate_room
    self.generate_room_exit(new_region, exit_kind, exit_base_dir)
  File "/Users/glmatthe/Documents/Personal/AAGen/aagen/generator.py", line 806, in generate_room_exit
    self.extend_passage(conn, 30, possible_directions)
  File "/Users/glmatthe/Documents/Personal/AAGen/aagen/generator.py", line 907, in extend_passage
    [direction], connection.size()
  File "/Users/glmatthe/Documents/Personal/AAGen/aagen/geometry.py", line 299, in construct_intersection
    exit_45))
AssertionError: Even after adjusting from <LineString: [(100, 0), (105.25, -5.25)]>, <LineString: [(100, -10), (105.25, -15.25)]> is not grid-aligned to <Direction: southwest>

[glennmatthews]

Not reproducible following commit 4fe7433