Merge bitcoin#19391: RPC/Mining: Clean out pre-Segwit miner compatibi…

…lity code

90a5dfa RPC/Mining: Clean out pre-Segwit miner compatibility code (Luke Dashjr)

Pull request description:

  This is dead code post-Segwit.

ACKs for top commit:
  achow101:
    ACK 90a5dfa

Tree-SHA512: 5970aa3548d2a7da7c6e83fb9b910529faab10251b115122cec833bb7d3a54c7cb0714c1a873807be04c7817bb827c7ece1e20e8fa4c907aa58688487d0ec44d

src/rpc/mining.cpp

@@ -598,7 +598,6 @@ static RPCHelpMan getblocktemplate()
     std::string strMode = "template";
     UniValue lpval = NullUniValue;
     std::set<std::string> setClientRules;
-    int64_t nMaxVersionPreVB = -1;
     CChainState& active_chainstate = chainman.ActiveChainstate();
     CChain& active_chain = active_chainstate.m_chain;
     if (!request.params[0].isNull())
@@ -650,12 +649,6 @@ static RPCHelpMan getblocktemplate()
                 const UniValue& v = aClientRules[i];
                 setClientRules.insert(v.get_str());
             }
-        } else {
-            // NOTE: It is important that this NOT be read if versionbits is supported
-            const UniValue& uvMaxVersion = find_value(oparam, "maxversion");
-            if (uvMaxVersion.isNum()) {
-                nMaxVersionPreVB = uvMaxVersion.getInt<int64_t>();
-            }
         }
     }
 
@@ -863,7 +856,6 @@ static RPCHelpMan getblocktemplate()
                 if (setClientRules.find(vbinfo.name) == setClientRules.end()) {
                     // Not supported by the client; make sure it's safe to proceed
                     if (!vbinfo.gbt_force) {
-                        // If we do anything other than throw an exception here, be sure version/force isn't sent to old clients
                         throw JSONRPCError(RPC_INVALID_PARAMETER, strprintf("Support for '%s' rule requires explicit client support", vbinfo.name));
                     }
                 }
@@ -876,14 +868,6 @@ static RPCHelpMan getblocktemplate()
     result.pushKV("vbavailable", vbavailable);
     result.pushKV("vbrequired", int(0));
 
-    if (nMaxVersionPreVB >= 2) {
-        // If VB is supported by the client, nMaxVersionPreVB is -1, so we won't get here
-        // Because BIP 34 changed how the generation transaction is serialized, we can only use version/force back to v2 blocks
-        // This is safe to do [otherwise-]unconditionally only because we are throwing an exception above if a non-force deployment gets activated
-        // Note that this can probably also be removed entirely after the first BIP9 non-force deployment (ie, probably segwit) gets activated
-        aMutable.push_back("version/force");
-    }
-
     result.pushKV("previousblockhash", pblock->hashPrevBlock.GetHex());
     result.pushKV("transactions", transactions);
     result.pushKV("coinbaseaux", aux);