test: Add test for loadtxoutset when headers are not synced

test/functional/feature_assumeutxo.py

@@ -113,6 +113,13 @@ def expected_error(log_msg="", rpc_details=""):
                 f.write(valid_snapshot_contents[(32 + 8 + offset + len(content)):])
             expected_error(log_msg=f"[snapshot] bad snapshot content hash: expected a4bf3407ccb2cc0145c49ebba8fa91199f8a3903daf0883875941497d2493c27, got {wrong_hash}")
 
+    def test_headers_not_synced(self, valid_snapshot_path):
+        self.log.info("Test loading snapshot when headers are not synced")
+        for node in self.nodes:
+            assert_raises_rpc_error(-32603, "The base block header (3bb7ce5eba0be48939b7a521ac1ba9316afee2c7bada3a0cca24188e6d7d96c0) must appear in the headers chain. Make sure all headers are syncing, and call this RPC again.",
+                                    node.loadtxoutset,
+                                    valid_snapshot_path)
+
     def test_invalid_chainstate_scenarios(self):
         self.log.info("Test different scenarios of invalid snapshot chainstate in datadir")
 
@@ -166,6 +173,8 @@ def run_test(self):
         for n in self.nodes:
             n.setmocktime(n.getblockheader(n.getbestblockhash())['time'])
 
+        self.test_headers_not_synced(dump_output['path'])
+
         # Generate a series of blocks that `n0` will have in the snapshot,
         # but that n1 doesn't yet see. In order for the snapshot to activate,
         # though, we have to ferry over the new headers to n1 so that it