Fix refcount test failing under pytest assertion rewriting

test_iterator_callback_no_leak fails on Python 3.11 in CI: pytest's
assertion rewriting explodes the assert expression into frame
temporaries, and one of them holds backend.cache[0] while
sys.getrefcount runs, inflating the count from 2 to 3. On 3.14 the
temporary does not survive, so the test passes there.

Keep the getrefcount call out of the assert so no rewritten temporary
can hold the object.

Assisted-by: Kimi Code

Author: jdavid

test/test_refdb_backend.py

@@ -209,7 +209,11 @@ def test_iterator_callback_no_leak(testrepo: Repository) -> None:
     assert backend.cache is not None
     refcount = sys.getrefcount(backend.cache[0])
     list(testrepo.references.iterator())
-    assert sys.getrefcount(backend.cache[0]) == refcount
+    # Keep the getrefcount call out of the assert: pytest's assertion
+    # rewriting holds the subscript result in a frame temporary, which
+    # inflates the refcount on some Python versions (e.g. 3.11).
+    new_refcount = sys.getrefcount(backend.cache[0])
+    assert new_refcount == refcount
 
 
 def test_write(repo: Repository) -> None: