Merge #17946: Fix GBT: Restore "!segwit" and "csv" to "rules" key

412d5fe QA: feature_segwit: Check that template "rules" includes "!segwit" as appropriate (Luke Dashjr)
2abe8cc Bugfix: Include "csv","!segwit" in "rules" (Luke Dashjr)

Pull request description:

  #16060 removed CSV & segwit from versionbits, breaking the "rules" key returned by GBT.

  Without this, miners don't know they're mining segwit blocks, and should fall back to pre-segwit block creation.

ACKs for top commit:
  sipa:
    ACK 412d5fe
  jnewbery:
    Tested ACK 412d5fe.

Tree-SHA512: 825d72e257dc0dd4941f2fe498d8d4f4f2a21b9505cd21a8f9eb7fb5d6d7dd9219347928cf90bb57a777920ce24295859763e64fa8a22ebb58fc2380f80f5615

Author: MarcoFalke

src/rpc/mining.cpp

@@ -787,6 +787,8 @@ static UniValue getblocktemplate(const JSONRPCRequest& request)
     result.pushKV("capabilities", aCaps);
 
     UniValue aRules(UniValue::VARR);
+    aRules.push_back("csv");
+    if (!fPreSegWit) aRules.push_back("!segwit");
     UniValue vbavailable(UniValue::VOBJ);
     for (int j = 0; j < (int)Consensus::MAX_VERSION_BITS_DEPLOYMENTS; ++j) {
         Consensus::DeploymentPos pos = Consensus::DeploymentPos(j);

test/functional/feature_segwit.py

@@ -108,12 +108,7 @@ def run_test(self):
         assert tmpl['sigoplimit'] == 20000
         assert tmpl['transactions'][0]['hash'] == txid
         assert tmpl['transactions'][0]['sigops'] == 2
-        tmpl = self.nodes[0].getblocktemplate({'rules': ['segwit']})
-        assert tmpl['sizelimit'] == 1000000
-        assert 'weightlimit' not in tmpl
-        assert tmpl['sigoplimit'] == 20000
-        assert tmpl['transactions'][0]['hash'] == txid
-        assert tmpl['transactions'][0]['sigops'] == 2
+        assert '!segwit' not in tmpl['rules']
         self.nodes[0].generate(1)  # block 162
 
         balance_presetup = self.nodes[0].getbalance()
@@ -213,6 +208,7 @@ def run_test(self):
         assert tmpl['sigoplimit'] == 80000
         assert tmpl['transactions'][0]['txid'] == txid
         assert tmpl['transactions'][0]['sigops'] == 8
+        assert '!segwit' in tmpl['rules']
 
         self.nodes[0].generate(1)  # Mine a block to clear the gbt cache