Merge #15891: test: Require standard txs in regtest by default

fa89badf887dcc01e5bdece248b5e7d234fee227 test: Require standard txs in regtest (MarcoFalke)
fa9b4191609c3ef75e69d391eb91e4d5c1e0bcf5 test: Add test that mainnet requires standard txs (MarcoFalke)
fa613ca0a8f99c4771859de9e571878530d3ecb5 chainparams: Remove unused fMineBlocksOnDemand (MarcoFalke)

Pull request description:

  I don't see a reason why regtest should allow non-standard txs, as it makes testing mainnet behaviour such as #15846 unnecessarily hard and unintuitive.

  Of course, testnet policy remains unchanged to allow propagation of non-standard txs.

ACKs for top commit:
  ajtowns:
    ACK fa89badf887dcc01e5bdece248b5e7d234fee227

Tree-SHA512: c4c675affb054868850bd2683aa07f4c741a448cbacb2ea8334191e105f426b0790fe6a468be61e9c5880d24154f7bf1c7075051697172dce92180c1bc3a1c90

3 files changed, 11 insertions, 8 deletions

diff --git a/src/chainparams.cpp b/src/chainparams.cpp
index b8e0ea23dd..f937e2754b 100644
--- a/src/chainparams.cpp
+++ b/src/chainparams.cpp
@@ -141,7 +141,7 @@ public:
 
         fDefaultConsistencyChecks = false;
         fRequireStandard = true;
-        fMineBlocksOnDemand = false;
+        m_is_test_chain = false;
 
         checkpointData = {
             {
@@ -247,7 +247,7 @@ public:
 
         fDefaultConsistencyChecks = false;
         fRequireStandard = false;
-        fMineBlocksOnDemand = false;
+        m_is_test_chain = true;
 
 
         checkpointData = {
@@ -324,8 +324,8 @@ public:
         vSeeds.clear();      //!< Regtest mode doesn't have any DNS seeds.
 
         fDefaultConsistencyChecks = true;
-        fRequireStandard = false;
-        fMineBlocksOnDemand = true;
+        fRequireStandard = true;
+        m_is_test_chain = true;
 
         checkpointData = {
             {
diff --git a/src/chainparams.h b/src/chainparams.h
index 6ff3dbb7e5..b3fcd77cea 100644
--- a/src/chainparams.h
+++ b/src/chainparams.h
@@ -66,13 +66,15 @@ public:
     bool DefaultConsistencyChecks() const { return fDefaultConsistencyChecks; }
     /** Policy: Filter transactions that do not match well-defined patterns */
     bool RequireStandard() const { return fRequireStandard; }
+    /** If this is a test chain */
+    bool IsTestChain() const { return m_is_test_chain; }
     uint64_t PruneAfterHeight() const { return nPruneAfterHeight; }
     /** Minimum free space (in GB) needed for data directory */
     uint64_t AssumedBlockchainSize() const { return m_assumed_blockchain_size; }
     /** Minimum free space (in GB) needed for data directory when pruned; Does not include prune target*/
     uint64_t AssumedChainStateSize() const { return m_assumed_chain_state_size; }
-    /** Make miner stop after a block is found. In RPC, don't return until nGenProcLimit blocks are generated */
-    bool MineBlocksOnDemand() const { return fMineBlocksOnDemand; }
+    /** Whether it is possible to mine blocks on demand (no retargeting) */
+    bool MineBlocksOnDemand() const { return consensus.fPowNoRetargeting; }
     /** Return the BIP70 network string (main, test or regtest) */
     std::string NetworkIDString() const { return strNetworkID; }
     /** Return true if the fallback fee is by default enabled for this network */
@@ -101,7 +103,7 @@ protected:
     std::vector<SeedSpec6> vFixedSeeds;
     bool fDefaultConsistencyChecks;
     bool fRequireStandard;
-    bool fMineBlocksOnDemand;
+    bool m_is_test_chain;
     CCheckpointData checkpointData;
     ChainTxData chainTxData;
     bool m_fallback_fee_enabled;
diff --git a/src/init.cpp b/src/init.cpp
index 8f0c896f01..26b2f9d6c2 100644
--- a/src/init.cpp
+++ b/src/init.cpp
@@ -1150,8 +1150,9 @@ bool AppInitParameterInteraction()
     }
 
     fRequireStandard = !gArgs.GetBoolArg("-acceptnonstdtxn", !chainparams.RequireStandard());
-    if (chainparams.RequireStandard() && !fRequireStandard)
+    if (!chainparams.IsTestChain() && !fRequireStandard) {
         return InitError(strprintf("acceptnonstdtxn is not currently supported for %s chain", chainparams.NetworkIDString()));
+    }
     nBytesPerSigOp = gArgs.GetArg("-bytespersigop", nBytesPerSigOp);
 
     if (!g_wallet_init_interface.ParameterInteraction()) return false;