test: Add functional test for symlinked blocks directory

Author: laanwj

test/functional/feature_dirsymlinks.py

@@ -0,0 +1,39 @@
+#!/usr/bin/env python3
+# Copyright (c) 2022 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test successful startup with symlinked directories.
+"""
+
+import os
+import sys
+
+from test_framework.test_framework import BitcoinTestFramework, SkipTest
+
+
+def rename_and_link(*, from_name, to_name):
+    os.rename(from_name, to_name)
+    os.symlink(to_name, from_name)
+    assert os.path.islink(from_name) and os.path.isdir(from_name)
+
+class SymlinkTest(BitcoinTestFramework):
+    def skip_test_if_missing_module(self):
+        if sys.platform == 'win32':
+            raise SkipTest("Symlinks test skipped on Windows")
+
+    def set_test_params(self):
+        self.num_nodes = 1
+
+    def run_test(self):
+        self.stop_node(0)
+
+        rename_and_link(from_name=os.path.join(self.nodes[0].datadir, self.chain, "blocks"),
+                        to_name=os.path.join(self.nodes[0].datadir, self.chain, "newblocks"))
+        rename_and_link(from_name=os.path.join(self.nodes[0].datadir, self.chain, "chainstate"),
+                        to_name=os.path.join(self.nodes[0].datadir, self.chain, "newchainstate"))
+
+        self.start_node(0)
+
+
+if __name__ == '__main__':
+    SymlinkTest().main()

test/functional/test_runner.py

@@ -321,6 +321,7 @@
     'rpc_getdescriptorinfo.py',
     'rpc_mempool_entry_fee_fields_deprecation.py',
     'rpc_help.py',
+    'feature_dirsymlinks.py',
     'feature_help.py',
     'feature_shutdown.py',
     'p2p_ibd_txrelay.py',