Merge bitcoin/bitcoin#24421: miner: always assume we can build witness blocks

40e871d9b4e55f5b5f7ce2a89157cd3d9f152037 [miner] always assume we can create witness blocks (glozow)

Pull request description:

  Given the low possibility of a reorg reverting the segwit soft fork, there is no longer a need to check whether segwit is active to see if it's okay to add to the block template (see also #23512, #21009, etc). `TestBlockValidity()` is also run on the block template at the end of `CreateNewBlock()`, so any invalid block would be caught there.

ACKs for top commit:
  gruve-p:
    ACK https://github.com/bitcoin/bitcoin/pull/24421/commits/40e871d9b4e55f5b5f7ce2a89157cd3d9f152037
  jnewbery:
    utACK 40e871d9b4, although I disagree about changing the test for segwit transaction in mempool before activagtion, instead of just removing it: https://github.com/bitcoin/bitcoin/pull/24421#discussion_r822933721.
  achow101:
    ACK 40e871d9b4e55f5b5f7ce2a89157cd3d9f152037
  theStack:
    Code-review ACK 40e871d9b4e55f5b5f7ce2a89157cd3d9f152037

Tree-SHA512: bf4860bf2bed8339622d05228d11d60286edb0c32a9a3c434b8d154913c07ea56e50649f4af7009c2a1c6a58a81d2299ab43b41a6f16dee7d08cc89cc1603019

1 files changed, 10 insertions, 12 deletions

diff --git a/test/functional/feature_segwit.py b/test/functional/feature_segwit.py
index 6d7f1def88..50adc08d9a 100755
--- a/test/functional/feature_segwit.py
+++ b/test/functional/feature_segwit.py
@@ -117,11 +117,9 @@ class SegWitTest(BitcoinTestFramework):
         assert_equal(len(node.getblock(block[0])["tx"]), 2)
         self.sync_blocks()
 
-    def skip_mine(self, node, txid, sign, redeem_script=""):
+    def fail_mine(self, node, txid, sign, redeem_script=""):
         send_to_witness(1, node, getutxo(txid), self.pubkey[0], False, Decimal("49.998"), sign, redeem_script)
-        block = self.generate(node, 1)
-        assert_equal(len(node.getblock(block[0])["tx"]), 1)
-        self.sync_blocks()
+        assert_raises_rpc_error(-1, "unexpected witness data found", self.generate, node, 1)
 
     def fail_accept(self, node, error_msg, txid, sign, redeem_script=""):
         assert_raises_rpc_error(-26, error_msg, send_to_witness, use_p2wsh=1, node=node, utxo=getutxo(txid), pubkey=self.pubkey[0], encode_p2sh=False, amount=Decimal("49.998"), sign=sign, insert_redeem_script=redeem_script)
@@ -197,21 +195,21 @@ class SegWitTest(BitcoinTestFramework):
         assert_equal(self.nodes[1].getbalance(), 20 * Decimal("49.999"))
         assert_equal(self.nodes[2].getbalance(), 20 * Decimal("49.999"))
 
-        self.generate(self.nodes[0], 260)  # block 423
+        self.generate(self.nodes[0], 264)  # block 427
 
-        self.log.info("Verify witness txs are skipped for mining before the fork")
-        self.skip_mine(self.nodes[2], wit_ids[NODE_2][P2WPKH][0], True)  # block 424
-        self.skip_mine(self.nodes[2], wit_ids[NODE_2][P2WSH][0], True)  # block 425
-        self.skip_mine(self.nodes[2], p2sh_ids[NODE_2][P2WPKH][0], True)  # block 426
-        self.skip_mine(self.nodes[2], p2sh_ids[NODE_2][P2WSH][0], True)  # block 427
+        self.log.info("Verify witness txs cannot be mined before the fork")
+        self.fail_mine(self.nodes[2], wit_ids[NODE_2][P2WPKH][0], True)
+        self.fail_mine(self.nodes[2], wit_ids[NODE_2][P2WSH][0], True)
+        self.fail_mine(self.nodes[2], p2sh_ids[NODE_2][P2WPKH][0], True)
+        self.fail_mine(self.nodes[2], p2sh_ids[NODE_2][P2WSH][0], True)
 
         self.log.info("Verify unsigned p2sh witness txs without a redeem script are invalid")
         self.fail_accept(self.nodes[2], "mandatory-script-verify-flag-failed (Operation not valid with the current stack size)", p2sh_ids[NODE_2][P2WPKH][1], sign=False)
         self.fail_accept(self.nodes[2], "mandatory-script-verify-flag-failed (Operation not valid with the current stack size)", p2sh_ids[NODE_2][P2WSH][1], sign=False)
 
-        self.generate(self.nodes[2], 4)  # blocks 428-431
+        self.generate(self.nodes[0], 4)  # blocks 428-431
 
-        self.log.info("Verify previous witness txs skipped for mining can now be mined")
+        self.log.info("Verify previous witness txs can now be mined")
         assert_equal(len(self.nodes[2].getrawmempool()), 4)
         blockhash = self.generate(self.nodes[2], 1)[0]  # block 432 (first block with new rules; 432 = 144 * 3)
         assert_equal(len(self.nodes[2].getrawmempool()), 0)