Merge #21230: test: Fix NODE_NETWORK_LIMITED_MIN_BLOCKS disconnection

fa24247 test: Fix NODE_NETWORK_LIMITED_MIN_BLOCKS disconnection (MarcoFalke)
fab6995 test: Make test actually test something (MarcoFalke)
fae8f35 test: pep8 touched test (MarcoFalke)

Pull request description:

  Fix several bugs. Also, fix #21227

ACKs for top commit:
  jonasschnelli:
    utACK fa24247 - thanks for fixing.
  ryanofsky:
    Code review ACK fa24247 with caveat above that I don't really understand the problem or fix. But the cleanups look good and the fix does seem perfectly safe. More description would be welcome!

Tree-SHA512: 67f6ec92f6493aa822ae3fa8a7426a5acdc684044b8bafc0c65b652f63ccce969d0a6f1d1f099d6a91d05f478724869345b70335f2cfcfd00df46aef05cc4f9e

Author: jonasschnelli

test/functional/feature_blockfilterindex_prune.py

@@ -9,6 +9,7 @@
     assert_greater_than,
 )
 
+
 class FeatureBlockfilterindexPruneTest(BitcoinTestFramework):
     def set_test_params(self):
         self.num_nodes = 2
@@ -17,33 +18,37 @@ def set_test_params(self):
     def run_test(self):
         # test basic pruning compatibility & filter access of pruned blocks
         self.log.info("check if we can access a blockfilter when pruning is enabled but no blocks are actually pruned")
-        assert(len(self.nodes[1].getblockfilter(self.nodes[1].getbestblockhash())['filter']) > 0)
-        self.nodes[1].generate(500)
+        assert len(self.nodes[1].getblockfilter(self.nodes[1].getbestblockhash())['filter']) > 0
+        # Mine two batches of blocks to avoid hitting NODE_NETWORK_LIMITED_MIN_BLOCKS disconnection
+        self.nodes[1].generate(250)
+        self.sync_all()
+        self.nodes[1].generate(250)
         self.sync_all()
         self.log.info("prune some blocks")
         pruneheight = self.nodes[1].pruneblockchain(400)
-        assert(pruneheight != 0)
+        assert pruneheight != 0
         self.log.info("check if we can access the tips blockfilter when we have pruned some blocks")
-        assert(len(self.nodes[1].getblockfilter(self.nodes[1].getbestblockhash())['filter']) > 0)
+        assert len(self.nodes[1].getblockfilter(self.nodes[1].getbestblockhash())['filter']) > 0
         self.log.info("check if we can access the blockfilter of a pruned block")
-        assert(len(self.nodes[1].getblockfilter(self.nodes[1].getblockhash(2))['filter']) > 0)
+        assert len(self.nodes[1].getblockfilter(self.nodes[1].getblockhash(2))['filter']) > 0
         self.log.info("start node without blockfilterindex")
         self.stop_node(1)
         self.start_node(1, extra_args=self.extra_args[0])
         self.log.info("make sure accessing the blockfilters throws an error")
-        assert_raises_rpc_error(-1,"Index is not enabled for filtertype basic", self.nodes[1].getblockfilter, self.nodes[1].getblockhash(2))
+        assert_raises_rpc_error(-1, "Index is not enabled for filtertype basic", self.nodes[1].getblockfilter, self.nodes[1].getblockhash(2))
         self.nodes[1].generate(1000)
         self.log.info("prune below the blockfilterindexes best block while blockfilters are disabled")
         pruneheight_new = self.nodes[1].pruneblockchain(1000)
         assert_greater_than(pruneheight_new, pruneheight)
         self.stop_node(1)
         self.log.info("make sure we get an init error when starting the node again with block filters")
-        self.nodes[1].assert_start_raises_init_error(extra_args=self.extra_args[1])
-        self.nodes[1].assert_debug_log(["basic block filter index best block of the index goes beyond pruned data. Please disable the index or reindex (which will download the whole blockchain again)"])
+        with self.nodes[1].assert_debug_log(["basic block filter index best block of the index goes beyond pruned data. Please disable the index or reindex (which will download the whole blockchain again)"]):
+            self.nodes[1].assert_start_raises_init_error(extra_args=self.extra_args[1])
         self.log.info("make sure the node starts again with the -reindex arg")
         reindex_args = self.extra_args[1]
         reindex_args.append("-reindex")
         self.start_node(1, extra_args=reindex_args)
 
+
 if __name__ == '__main__':
     FeatureBlockfilterindexPruneTest().main()