Don't check merge base branch

tests/test_pr.py

@@ -66,6 +66,19 @@ class TestPRMergeStatus(unittest.TestCase):
         res = pr_merge_status(pr, branches, check_backport=True)
         self.assertEqual(res.title, expected_title)
 
+    @unittest.mock.patch("requests.get", side_effect=mocked_requests_get)
+    def test_pr_merge_status_no_check_master_345583(self, mock_get):
+        pr = 345583
+        branches = ["master", "nixos-unstable", "nixos-24.05"]
+        master_compare_url = "https://api.github.com/repos/NixOS/nixpkgs/compare/master...2c5fac3edf2d00d948253e392ec1604b29b38f14"
+
+        res = pr_merge_status(pr, branches, check_backport=False)
+        self.assertTrue(res.merged)
+        self.assertTrue(res.branches["master"])
+
+        urls_called = [call[0][0] for call in mock_get.call_args_list]
+        self.assertFalse(master_compare_url in urls_called)
+
 
 class TestCommitInBranch(unittest.TestCase):
     @unittest.mock.patch("requests.get", side_effect=mocked_requests_get)