fix segfaults in Python cFFI API and add tests

Several iterators in the Python cFFI API destroyed the objects they iterated
over too early (when the iterator was exhausted), causing subsequent segfaults
in common cases like creating a list from the iterator. This patch fixes the
segfaults and add tests to ensure that they don't happen again.

1 files changed, 31 insertions, 0 deletions

diff --git a/bindings/python-cffi/tests/test_database.py b/bindings/python-cffi/tests/test_database.py
index f1d12ea6..1557235d 100644
--- a/bindings/python-cffi/tests/test_database.py
+++ b/bindings/python-cffi/tests/test_database.py
@@ -303,6 +303,18 @@ class TestQuery:
         msgs = db.messages('*')
         assert isinstance(msgs, collections.abc.Iterator)
 
+    def test_messages_iterator(self, db):
+        for msg in db.messages('*'):
+            assert isinstance(msg, notmuch2.Message)
+            assert isinstance(msg.messageid, str)
+
+    def test_messages_iterator_list(self, db):
+        msgs = list(db.messages('*'))
+        assert len(msgs) == 3
+        for msg in msgs:
+            assert isinstance(msg, notmuch2.Message)
+            assert isinstance(msg.messageid, str)
+
     def test_message_no_results(self, db):
         msgs = db.messages('not_a_matching_query')
         with pytest.raises(StopIteration):
@@ -320,6 +332,25 @@ class TestQuery:
         threads = db.threads('*')
         assert isinstance(threads, collections.abc.Iterator)
 
+    def test_threads_iterator(self, db):
+        for t in db.threads('*'):
+            assert isinstance(t, notmuch2.Thread)
+            assert isinstance(t.threadid, str)
+            for msg in t:
+                assert isinstance(msg, notmuch2.Message)
+                assert isinstance(msg.messageid, str)
+
+    def test_threads_iterator_list(self, db):
+        threads = list(db.threads('*'))
+        assert len(threads) == 2
+        for t in threads:
+            assert isinstance(t, notmuch2.Thread)
+            assert isinstance(t.threadid, str)
+            msgs = list(t)
+            for msg in msgs:
+                assert isinstance(msg, notmuch2.Message)
+                assert isinstance(msg.messageid, str)
+
     def test_threads_no_match(self, db):
         threads = db.threads('not_a_matching_query')
         with pytest.raises(StopIteration):