p2p: Avoid InitError when downgrading peers.dat

fixes #24188
When downgrading, a peers.dat with a future version that has a minimum
required version larger than the downgraded version would cause an InitError.

This commit changes this behavior to overwrite the existing peers.dat with
a new empty one, while creating a backup in peers.dat.bak.

1 files changed, 8 insertions, 9 deletions

diff --git a/test/functional/feature_addrman.py b/test/functional/feature_addrman.py
index 14a4f8abb7..0fdefaa9c3 100755
--- a/test/functional/feature_addrman.py
+++ b/test/functional/feature_addrman.py
@@ -68,17 +68,16 @@ class AddrmanTest(BitcoinTestFramework):
             self.start_node(0, extra_args=["-checkaddrman=1"])
         assert_equal(self.nodes[0].getnodeaddresses(), [])
 
-        self.log.info("Check that addrman from future cannot be read")
+        self.log.info("Check that addrman from future is overwritten with new addrman")
         self.stop_node(0)
         write_addrman(peers_dat, lowest_compatible=111)
-        self.nodes[0].assert_start_raises_init_error(
-            expected_msg=init_error(
-                "Unsupported format of addrman database: 1. It is compatible with "
-                "formats >=111, but the maximum supported by this version of "
-                f"{self.config['environment']['PACKAGE_NAME']} is 4.: (.+)"
-            ),
-            match=ErrorMatch.FULL_REGEX,
-        )
+        assert_equal(os.path.exists(peers_dat + ".bak"), False)
+        with self.nodes[0].assert_debug_log([
+                f'Creating new peers.dat because the file version was not compatible ("{peers_dat}"). Original backed up to peers.dat.bak',
+        ]):
+            self.start_node(0)
+        assert_equal(self.nodes[0].getnodeaddresses(), [])
+        assert_equal(os.path.exists(peers_dat + ".bak"), True)
 
         self.log.info("Check that corrupt addrman cannot be read (EOF)")
         self.stop_node(0)