Merge bitcoin#29478: test: Test new header sync behavior in loadtxoutset

1ec6684 test: Add test for loadtxoutset when headers are not synced (Fabian Jahr)
2bc1ecf test: Remove unnecessary sync_blocks in assumeutxo tests (Fabian Jahr)

Pull request description:

  It adds a test for the change to `loadtxoutset` made in bitcoin#29345.  Before that change the test doesn't fail right away but times out after 10 minutes.

  Also removes a `sync_blocks` call that didn't seem to do anything valuable.

ACKs for top commit:
  achow101:
    ACK 1ec6684
  pablomartin4btc:
    tACK 1ec6684
  BrandonOdiwuor:
    ACK 1ec6684
  theStack:
    ACK 1ec6684

Tree-SHA512: 1337decdf91e4a4f7213fcf8ace1d705e5c1422e0ac3872a59b5be9c33e743850cb8f5f7474750a534952eefd5cfe43fe85a54efb9bc0e47515136a2903676e5

Author: achow101

test/functional/feature_assumeutxo.py

@@ -113,6 +113,12 @@ 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):
+        for node in self.nodes[1:]:
+            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")
 
@@ -166,26 +172,12 @@ def run_test(self):
         for n in self.nodes:
             n.setmocktime(n.getblockheader(n.getbestblockhash())['time'])
 
-        self.sync_blocks()
-
         # 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
-        # isn't waiting forever to see the header of the snapshot's base block
-        # while disconnected from n0.
+        # but that n1 and n2 don't yet see.
         for i in range(100):
             if i % 3 == 0:
                 self.mini_wallet.send_self_transfer(from_node=n0)
             self.generate(n0, nblocks=1, sync_fun=self.no_op)
-            newblock = n0.getblock(n0.getbestblockhash(), 0)
-
-            # make n1 aware of the new header, but don't give it the block.
-            n1.submitheader(newblock)
-            n2.submitheader(newblock)
-
-        # Ensure everyone is seeing the same headers.
-        for n in self.nodes:
-            assert_equal(n.getblockchaininfo()["headers"], SNAPSHOT_BASE_HEIGHT)
 
         self.log.info("-- Testing assumeutxo + some indexes + pruning")
 
@@ -195,6 +187,23 @@ def run_test(self):
         self.log.info(f"Creating a UTXO snapshot at height {SNAPSHOT_BASE_HEIGHT}")
         dump_output = n0.dumptxoutset('utxos.dat')
 
+        self.log.info("Test loading snapshot when headers are not synced")
+        self.test_headers_not_synced(dump_output['path'])
+
+        # In order for the snapshot to activate, we have to ferry over the new
+        # headers to n1 and n2 so that they see the header of the snapshot's
+        # base block while disconnected from n0.
+        for i in range(1, 300):
+            block = n0.getblock(n0.getblockhash(i), 0)
+            # make n1 and n2 aware of the new header, but don't give them the
+            # block.
+            n1.submitheader(block)
+            n2.submitheader(block)
+
+        # Ensure everyone is seeing the same headers.
+        for n in self.nodes:
+            assert_equal(n.getblockchaininfo()["headers"], SNAPSHOT_BASE_HEIGHT)
+
         assert_equal(
             dump_output['txoutset_hash'],
             "a4bf3407ccb2cc0145c49ebba8fa91199f8a3903daf0883875941497d2493c27")

test/functional/wallet_assumeutxo.py

@@ -62,8 +62,6 @@ def run_test(self):
         for n in self.nodes:
             n.setmocktime(n.getblockheader(n.getbestblockhash())['time'])
 
-        self.sync_blocks()
-
         n0.createwallet('w')
         w = n0.get_wallet_rpc("w")