[net processing] Only accept `sendcmpct` with version=2

Subsequent commits will remove support for other versions of compact blocks.

Add a test that a received `sendcmpct` message with version = 1 is
ignored.

1 files changed, 8 insertions, 0 deletions

diff --git a/test/functional/p2p_compactblocks.py b/test/functional/p2p_compactblocks.py
index 6bf4068944..8eec8dbc0d 100755
--- a/test/functional/p2p_compactblocks.py
+++ b/test/functional/p2p_compactblocks.py
@@ -179,6 +179,7 @@ class CompactBlocksTest(BitcoinTestFramework):
 
     # Test "sendcmpct" (between peers preferring the same version):
     # - No compact block announcements unless sendcmpct is sent.
+    # - If sendcmpct is sent with version = 1, the message is ignored.
     # - If sendcmpct is sent with version > 2, the message is ignored.
     # - If sendcmpct is sent with boolean 0, then block announcements are not
     #   made with compact blocks.
@@ -221,6 +222,13 @@ class CompactBlocksTest(BitcoinTestFramework):
         # Before each test, sync the headers chain.
         test_node.request_headers_and_sync(locator=[tip])
 
+        # Now try a SENDCMPCT message with too-low version
+        test_node.send_and_ping(msg_sendcmpct(announce=True, version=1))
+        check_announcement_of_new_block(node, test_node, lambda p: "cmpctblock" not in p.last_message)
+
+        # Headers sync before next test.
+        test_node.request_headers_and_sync(locator=[tip])
+
         # Now try a SENDCMPCT message with too-high version
         test_node.send_and_ping(msg_sendcmpct(announce=True, version=3))
         check_announcement_of_new_block(node, test_node, lambda p: "cmpctblock" not in p.last_message)