Add pickle test for v13 Random.

The internal C type will have a slight change, so the old format needs
to stay supported.

Author: HexDecimal

MANIFEST.in

@@ -3,6 +3,6 @@ include *.py *.cfg *.txt *.rst *.toml
 recursive-include tcod *.py *.c *.h
 
 recursive-include libtcod/src *.glsl* *.c *.h
-include libtcod/*.txt libtcod/*.md
+include libtcod/*.txt libtcod/*.md tests/data/*.pkl
 
 exclude tcod/*/SDL2.dll

tests/data/README.md

@@ -0,0 +1,3 @@
+Data files for tests, such as old pickle streams.
+
+Remember to add new file types to `MANIFEST.in`.

tests/data/random_v13.pkl

@@ -1,4 +1,5 @@
 import copy
+import pathlib
 import pickle
 
 import tcod
@@ -26,3 +27,10 @@ def test_tcod_random_pickle() -> None:
     assert rand.uniform(0, 1) == rand2.uniform(0, 1)
     assert rand.uniform(0, 1) == rand2.uniform(0, 1)
     assert rand.uniform(0, 1) == rand2.uniform(0, 1)
+
+
+def test_load_rng_v13() -> None:
+    with open(pathlib.Path(__file__).parent / "data/random_v13.pkl", "rb") as f:
+        rand: tcod.random.Random = pickle.load(f)
+    assert rand.randint(0, 0xFFFF) == 56422
+    assert rand.randint(0, 0xFFFF) == 15795