Random map generation failure crashes the game (dedicated server).

[James103]

Version of OpenTTD

1.9.2 and master-20190707

Expected result

Random map generation failure should cause the next attempt to use a random seed that should hopefully succeed (regardless of if a set seed was input into the "newmap" / "newgame" command)

Actual result

Random map generation failure crashes the game with NOT_REACHED triggered at line 140 of d:\a\1\s\src\thread\thread_win32.cpp while in a dedicated server. Crash info has been attached.

Steps to reproduce

Set the map generation settings as follows (from my openttd.cfg):

town_name = 21
landscape = temperate
snow_line_height = 15
starting_year = 3000
land_generator = 1
oil_refinery_limit = 48
tgen_smoothness = 3
variety = 0
generation_seed = 32
tree_placer = 0
heightmap_rotation = 0
se_flat_world_height = 1
map_x = 6
map_y = 6
water_borders = 15
custom_town_number = 5000
custom_sea_level = 90
min_river_length = 16
river_route_random = 5
amount_of_rivers = 0

Then, run openttd -D ::1 (dedicated server) and type newmap 32 or newgame 32 into the console. If that doesn't work, try some other seeds/settings. If the map generation fails, then the game crashes.

[LordAro]

Interesting that it also crashes in master, given the threading code has been rewritten since 1.9.x. Presumably the error message is different, as thread_win32.cpp doesn't exist anymore :)

[James103]

@LordAro
I haven't tested master (20190707) yet when you made your comment. Actually, OpenTTD master (20190707-master- 1e72393) does crash (Assertion failed at line 61 of d:\a\1\s\src\newgrf_storage.cpp: ignore_prev_mode || !gameloop) when random map generation fails as a dedicated server. Crash logs and console log has been attached.

[James103]

I can't give you the full stacktrace, but I can tell that the assert was triggered because

OpenTTD/src/newgrf_storage.cpp

Line 57 in 1e72393

/* static */ void BasePersistentStorageArray::SwitchMode(PersistentStorageMode mode, bool ignore_prev_mode)

was called twice in a row, both times trying to enter the game loop (PSM_ENTER_GAMELOOP).