@@ -561,14 +561,12 @@ CBlockPolicyEstimator::CBlockPolicyEstimator(const fs::path& estimation_filepath
 
     AutoFile est_file{fsbridge::fopen(m_estimation_filepath, "rb")};
 
-    // Whenever the fee estimation file is not present return early
     if (est_file.IsNull()) {
         LogPrintf("%s is not found. Continue anyway.\n", fs::PathToString(m_estimation_filepath));
         return;
     }
 
     std::chrono::hours file_age = GetFeeEstimatorFileAge();
-    // fee estimate file must not be too old to avoid wrong fee estimates.
     if (file_age > MAX_FILE_AGE && !read_stale_estimates) {
         LogPrintf("Fee estimation file %s too old (age=%lld > %lld hours) and will not be used to avoid serving stale estimates.\n", fs::PathToString(m_estimation_filepath), Ticks<std::chrono::hours>(file_age), Ticks<std::chrono::hours>(MAX_FILE_AGE));
         return;
 
@@ -25,8 +25,9 @@
 // How often to flush fee estimates to fee_estimates.dat.
 static constexpr std::chrono::hours FEE_FLUSH_INTERVAL{1};
 
-/** fee_estimates.dat that are more than 60 hours (2.5 days) will not be read,
- * as the estimates in the file are stale.
+/** fee_estimates.dat that are more than 60 hours (2.5 days) old will not be read,
+ * as fee estimates are based on historical data and may be inaccurate if
+ * network activity has changed.
  */
 static constexpr std::chrono::hours MAX_FILE_AGE{60};
 
 
@@ -9,10 +9,7 @@
 - Mine a fork that requires disconnecting the tip.
 - Verify that dashd AbortNode's.
 """
-
 from test_framework.test_framework import BitcoinTestFramework
-from test_framework.util import get_datadir_path
-import os
 
 
 class AbortNodeTest(BitcoinTestFramework):
@@ -26,10 +23,9 @@ def setup_network(self):
 
     def run_test(self):
         self.generate(self.nodes[0], 3, sync_fun=self.no_op)
-        datadir = get_datadir_path(self.options.tmpdir, 0)
 
         # Deleting the undo file will result in reorg failure
-        os.unlink(os.path.join(datadir, self.chain, 'blocks', 'rev00000.dat'))
+        (self.nodes[0].blocks_path / "rev00000.dat").unlink()
 
         # Connecting to a node with a more work chain will trigger a reorg
         # attempt.
 
@@ -52,7 +52,7 @@ def set_test_params(self):
         self.num_nodes = 1
 
     def run_test(self):
-        peers_dat = os.path.join(self.nodes[0].datadir, self.chain, "peers.dat")
+        peers_dat = os.path.join(self.nodes[0].chain_path, "peers.dat")
         init_error = lambda reason: (
             f"Error: Invalid or corrupt peers.dat \\({reason}\\). If you believe this "
             f"is a bug, please report it to {self.config['environment']['PACKAGE_BUGREPORT']}. "
 
@@ -23,9 +23,7 @@ def set_test_params(self):
         self.disable_autoconnect = False
 
     def run_test(self):
-        node_anchors_path = os.path.join(
-            self.nodes[0].datadir, "regtest", "anchors.dat"
-        )
+        node_anchors_path = self.nodes[0].chain_path / "anchors.dat"
 
         self.log.info("When node starts, check if anchors.dat doesn't exist")
         assert not os.path.exists(node_anchors_path)
 
@@ -121,7 +121,7 @@ def test_asmap_health_check(self):
 
     def run_test(self):
         self.node = self.nodes[0]
-        self.datadir = os.path.join(self.node.datadir, self.chain)
+        self.datadir = self.node.chain_path
         self.default_asmap = os.path.join(self.datadir, DEFAULT_ASMAP_FILENAME)
         self.asmap_raw = os.path.join(os.path.dirname(os.path.realpath(__file__)), ASMAP)
 
 
@@ -18,7 +18,7 @@ def set_test_params(self):
 
     def run_test(self):
         self.stop_node(0)
-        assert os.path.isdir(os.path.join(self.nodes[0].datadir, self.chain, "blocks"))
+        assert os.path.isdir(os.path.join(self.nodes[0].chain_path, "blocks"))
         assert not os.path.isdir(os.path.join(self.nodes[0].datadir, "blocks"))
         shutil.rmtree(self.nodes[0].datadir)
         initialize_datadir(self.options.tmpdir, 0, self.chain)
@@ -31,7 +31,7 @@ def run_test(self):
         self.log.info("mining blocks..")
         self.generatetoaddress(self.nodes[0], 10, self.nodes[0].get_deterministic_priv_key().address)
         assert os.path.isfile(os.path.join(blocksdir_path, self.chain, "blocks", "blk00000.dat"))
-        assert os.path.isdir(os.path.join(self.nodes[0].datadir, self.chain, "blocks", "index"))
+        assert os.path.isdir(os.path.join(self.nodes[0].chain_path, "blocks", "index"))
 
 
 if __name__ == '__main__':
 
@@ -7,6 +7,7 @@
 import os
 import pathlib
 import re
+import shutil
 import sys
 import tempfile
 import time
@@ -32,7 +33,7 @@ def test_config_file_parser(self):
         self.stop_node(0)
 
         # Check that startup fails if conf= is set in bitcoin.conf or in an included conf file
-        bad_conf_file_path = os.path.join(self.options.tmpdir, 'node0', 'bitcoin_bad.conf')
+        bad_conf_file_path = self.nodes[0].datadir_path / "bitcoin_bad.conf"
         util.write_config(bad_conf_file_path, n=0, chain='', extra_config=f'conf=some.conf\n')
         conf_in_config_file_err = 'Error: Error reading configuration file: conf cannot be set in the configuration file; use includeconf= if you want to include additional config files'
         self.nodes[0].assert_start_raises_init_error(
@@ -75,7 +76,7 @@ def test_config_file_parser(self):
                 conf.write("wallet=foo\n")
             self.nodes[0].assert_start_raises_init_error(expected_msg=f'Error: Config setting for -wallet only applied on {self.chain} network when in [{self.chain}] section.')
 
-        main_conf_file_path = os.path.join(self.options.tmpdir, 'node0', 'dash_main.conf')
+        main_conf_file_path = self.nodes[0].datadir_path / "dash_main.conf"
         util.write_config(main_conf_file_path, n=0, chain='', extra_config=f'includeconf={inc_conf_file_path}\n')
         with open(inc_conf_file_path, 'w', encoding='utf-8') as conf:
             conf.write('acceptnonstdtxn=1\n')
@@ -367,6 +368,20 @@ def test_ignored_default_conf(self):
             f'is being used instead.') + r"[\s\S]*", env=env, match=ErrorMatch.FULL_REGEX)
         node.args = node_args
 
+    def test_acceptstalefeeestimates_arg_support(self):
+        self.log.info("Test -acceptstalefeeestimates option support")
+        conf_file = self.nodes[0].datadir_path / "dash.conf"
+        existing_paths = set(self.nodes[0].datadir_path.iterdir())
+        for chain, chain_name in {("main", ""), ("test", "testnet3"), ("devnet", "devnet")}:
+            util.write_config(conf_file, n=0, chain=chain_name, extra_config='acceptstalefeeestimates=1\n')
+            self.nodes[0].assert_start_raises_init_error(expected_msg=f'Error: acceptstalefeeestimates is not supported on {chain} chain.')
+        util.write_config(conf_file, n=0, chain="regtest")  # Reset to regtest
+        # Remove the chain dirs created by the failed starts above, so node0 keeps a single
+        # chain dir holding a debug.log, as combine_logs.py (run by Dash CI on every test) expects
+        for path in set(self.nodes[0].datadir_path.iterdir()) - existing_paths:
+            if path.is_dir():
+                shutil.rmtree(path)
+
     def run_test(self):
         self.test_log_buffer()
         self.test_args_log()
@@ -380,6 +395,7 @@ def run_test(self):
         self.test_invalid_command_line_options()
         self.test_ignored_conf()
         self.test_ignored_default_conf()
+        self.test_acceptstalefeeestimates_arg_support()
 
         # Remove the -datadir argument so it doesn't override the config file
         self.nodes[0].args = [arg for arg in self.nodes[0].args if not arg.startswith("-datadir")]
 
@@ -26,7 +26,7 @@ def run_test(self):
         self.stop_node(0)
 
         rename_and_link(
-            from_name=self.nodes[0].chain_path / "blocks",
+            from_name=self.nodes[0].blocks_path,
             to_name=dir_new_blocks,
         )
         rename_and_link(
 
@@ -3,7 +3,6 @@
 # Distributed under the MIT software license, see the accompanying
 # file COPYING or http://www.opensource.org/licenses/mit-license.php.
 """Check that it's not possible to start a second bitcoind instance using the same datadir or wallet."""
-import os
 import random
 import string
 
@@ -26,7 +25,7 @@ def setup_network(self):
         self.nodes[0].wait_for_rpc_connection()
 
     def run_test(self):
-        datadir = os.path.join(self.nodes[0].datadir, self.chain)
+        datadir = self.nodes[0].chain_path
         self.log.info(f"Using datadir {datadir}")
 
         self.log.info("Check that we can't start a second dashd instance using the same datadir")
@@ -43,7 +42,7 @@ def run_test(self):
             def check_wallet_filelock(descriptors):
                 wallet_name = ''.join([random.choice(string.ascii_lowercase) for _ in range(6)])
                 self.nodes[0].createwallet(wallet_name=wallet_name, descriptors=descriptors)
-                wallet_dir = os.path.join(datadir, 'wallets')
+                wallet_dir = self.nodes[0].wallets_path
                 self.log.info("Check that we can't start a second dashd instance using the same wallet")
                 if descriptors:
                     expected_msg = f"Error: SQLiteDatabase: Unable to obtain an exclusive lock on the database, is it being used by another instance of {self.config['environment']['PACKAGE_NAME']}?"
Original file line number	Diff line number	Diff line change
`@@ -26,7 +26,7 @@ def run_test(self):`
`26`	`26`	`self.stop_node(0)`
`27`	`27`
`28`	`28`	`rename_and_link(`
`29`		`- from_name=self.nodes[0].chain_path / "blocks",`
	`29`	`+ from_name=self.nodes[0].blocks_path,`
`30`	`30`	`to_name=dir_new_blocks,`
`31`	`31`	`)`
`32`	`32`	`rename_and_link(`