Merge #16551: test: Test that low difficulty chain fork is rejected

333317ce6b67aa92f7363d48cd750712190b4b6b test: Test that low difficulty chain fork is rejected (MarcoFalke)
fa31dc1bf4ee471c4641eef8de02702ba0619ae7 test: Pass down correct chain name in tests (MarcoFalke)

Pull request description:

  To prevent OOM, Bitcoin Core will reject chain forks at low difficulty by default. This is the only use-case of checkpoints, so add a test for it to make sure the feature works as expected. If it didn't work, checkpoints would have no use-case and we might as well remove them

ACKs for top commit:
  Sjors:
    Thanks for adding the node 1 example. Code review ACK 333317c

Tree-SHA512: 90dffa540d0904f3cffb61d2382b1a26f84fe9560b7013e4461546383add31a8757b350616a6d43217c59ef7b8b2a1b62bb3bab582c679cbb2c660a782ce7be1

3 files changed, 12 insertions, 4 deletions

diff --git a/test/functional/test_framework/mininode.py b/test/functional/test_framework/mininode.py
index 779863df79..166438cf70 100755
--- a/test/functional/test_framework/mininode.py
+++ b/test/functional/test_framework/mininode.py
@@ -111,7 +111,7 @@ class P2PConnection(asyncio.Protocol):
     def is_connected(self):
         return self._transport is not None
 
-    def peer_connect(self, dstaddr, dstport, net="regtest"):
+    def peer_connect(self, dstaddr, dstport, *, net):
         assert not self.is_connected
         self.dstaddr = dstaddr
         self.dstport = dstport
diff --git a/test/functional/test_framework/test_node.py b/test/functional/test_framework/test_node.py
index 55e6d4caa6..d8bfdfd040 100755
--- a/test/functional/test_framework/test_node.py
+++ b/test/functional/test_framework/test_node.py
@@ -489,7 +489,7 @@ class TestNode():
         if 'dstaddr' not in kwargs:
             kwargs['dstaddr'] = '127.0.0.1'
 
-        p2p_conn.peer_connect(**kwargs)()
+        p2p_conn.peer_connect(**kwargs, net=self.chain)()
         self.p2ps.append(p2p_conn)
         if wait_for_verack:
             p2p_conn.wait_for_verack()
diff --git a/test/functional/test_framework/util.py b/test/functional/test_framework/util.py
index 6d74447ada..f9f5fe553e 100644
--- a/test/functional/test_framework/util.py
+++ b/test/functional/test_framework/util.py
@@ -287,14 +287,22 @@ def initialize_datadir(dirname, n, chain):
     datadir = get_datadir_path(dirname, n)
     if not os.path.isdir(datadir):
         os.makedirs(datadir)
+    # Translate chain name to config name
+    if chain == 'testnet3':
+        chain_name_conf_arg = 'testnet'
+        chain_name_conf_section = 'test'
+    else:
+        chain_name_conf_arg = chain
+        chain_name_conf_section = chain
     with open(os.path.join(datadir, "bitcoin.conf"), 'w', encoding='utf8') as f:
-        f.write("{}=1\n".format(chain))
-        f.write("[{}]\n".format(chain))
+        f.write("{}=1\n".format(chain_name_conf_arg))
+        f.write("[{}]\n".format(chain_name_conf_section))
         f.write("port=" + str(p2p_port(n)) + "\n")
         f.write("rpcport=" + str(rpc_port(n)) + "\n")
         f.write("server=1\n")
         f.write("keypool=1\n")
         f.write("discover=0\n")
+        f.write("dnsseed=0\n")
         f.write("listenonion=0\n")
         f.write("printtoconsole=0\n")
         f.write("upnp=0\n")