Fix ts unpickling

Author: benjeffery

python/CHANGELOG.rst

@@ -23,6 +23,9 @@
 
 **Fixes**
 
+- Tree sequences were not properly init'd after unpickling
+  (:user:`benjeffery`, :issue:`1297`, :pr:`1298`)
+
 --------------------
 [0.3.5] - 2021-03-16
 --------------------

python/tests/test_highlevel.py

@@ -1807,7 +1807,11 @@ def test_table_metadata_round_trip_via_row_getters(self):
 
 
 def test_pickle_round_trip(ts_fixture):
-    assert ts_fixture.tables == pickle.loads(pickle.dumps(ts_fixture)).tables
+    for protocol in range(pickle.HIGHEST_PROTOCOL + 1):
+        ts = pickle.loads(pickle.dumps(ts_fixture, protocol=protocol))
+        assert ts.tables == ts_fixture.tables
+        # Do some thing to check the ts is init'd properly
+        ts.draw_text()
 
 
 class TestFileUuid(HighLevelTestCase):

python/tskit/trees.py

@@ -3315,7 +3315,7 @@ def __getstate__(self):
         return self.dump_tables()
 
     def __setstate__(self, tc):
-        self._ll_tree_sequence = tc.tree_sequence().ll_tree_sequence
+        self.__init__(tc.tree_sequence().ll_tree_sequence)
 
     def __eq__(self, other):
         return self.tables == other.tables