Merge #13527: policy: Remove promiscuousmempoolflags

faa24441ec047ec336b86f586016b9d318c1c0ad policy: Remove promiscuousmempoolflags (MarcoFalke)

Pull request description:

  It seems odd to clutter validation code with features that can only ever be used for testing (testnet or regtest). Removing that test-only code makes the mempool logic less painful to understand and easier to reason about when changed or refactored in the future.

Tree-SHA512: 3b897aa9604ac8d82ebe9573c6efd468c93ddaa08d378ebc902e247b7aa6c68fcde71e5b449c08f17a067146cdc66dc50a67ce06d07607c27e5189a49c3fba3f

2 files changed, 7 insertions, 19 deletions

diff --git a/src/miner.cpp b/src/miner.cpp
index c32dc26f86..6cd78b5c18 100644
--- a/src/miner.cpp
+++ b/src/miner.cpp
@@ -133,8 +133,11 @@ std::unique_ptr<CBlockTemplate> BlockAssembler::CreateNewBlock(const CScript& sc
 
     // Decide whether to include witness transactions
     // This is only needed in case the witness softfork activation is reverted
-    // (which would require a very deep reorganization) or when
-    // -promiscuousmempoolflags is used.
+    // (which would require a very deep reorganization).
+    // Note that the mempool would accept transactions with witness data before
+    // IsWitnessEnabled, but we would only ever mine blocks after IsWitnessEnabled
+    // unless there is a massive block reorganization with the witness softfork
+    // not activated.
     // TODO: replace this with a call to main to assess validity of a mempool
     // transaction (which in most cases can be a no-op).
     fIncludeWitness = IsWitnessEnabled(pindexPrev, chainparams.GetConsensus()) && fMineWitnessTx;
diff --git a/src/validation.cpp b/src/validation.cpp
index 702a8d7e05..fceb135854 100644
--- a/src/validation.cpp
+++ b/src/validation.cpp
@@ -894,10 +894,7 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool
             }
         }
 
-        unsigned int scriptVerifyFlags = STANDARD_SCRIPT_VERIFY_FLAGS;
-        if (!chainparams.RequireStandard()) {
-            scriptVerifyFlags = gArgs.GetArg("-promiscuousmempoolflags", scriptVerifyFlags);
-        }
+        constexpr unsigned int scriptVerifyFlags = STANDARD_SCRIPT_VERIFY_FLAGS;
 
         // Check against previous transactions
         // This is done last to help prevent CPU exhaustion denial-of-service attacks.
@@ -932,20 +929,8 @@ static bool AcceptToMemoryPoolWorker(const CChainParams& chainparams, CTxMemPool
         // transactions into the mempool can be exploited as a DoS attack.
         unsigned int currentBlockScriptVerifyFlags = GetBlockScriptFlags(chainActive.Tip(), Params().GetConsensus());
         if (!CheckInputsFromMempoolAndCache(tx, state, view, pool, currentBlockScriptVerifyFlags, true, txdata)) {
-            // If we're using promiscuousmempoolflags, we may hit this normally
-            // Check if current block has some flags that scriptVerifyFlags
-            // does not before printing an ominous warning
-            if (!(~scriptVerifyFlags & currentBlockScriptVerifyFlags)) {
-                return error("%s: BUG! PLEASE REPORT THIS! ConnectInputs failed against latest-block but not STANDARD flags %s, %s",
+            return error("%s: BUG! PLEASE REPORT THIS! CheckInputs failed against latest-block but not STANDARD flags %s, %s",
                     __func__, hash.ToString(), FormatStateMessage(state));
-            } else {
-                if (!CheckInputs(tx, state, view, true, MANDATORY_SCRIPT_VERIFY_FLAGS, true, false, txdata)) {
-                    return error("%s: ConnectInputs failed against MANDATORY but not STANDARD flags due to promiscuous mempool %s, %s",
-                        __func__, hash.ToString(), FormatStateMessage(state));
-                } else {
-                    LogPrintf("Warning: -promiscuousmempool flags set to not include currently enforced soft forks, this may break mining or otherwise cause instability!\n");
-                }
-            }
         }
 
         if (test_accept) {