datacarrier: deprecate startup arguments for future removal

Author: instagibbs

src/init.cpp

@@ -630,9 +630,9 @@ void SetupServerArgs(ArgsManager& argsman, bool can_listen_ipc)
     argsman.AddArg("-dustrelayfee=<amt>", strprintf("Fee rate (in %s/kvB) used to define dust, the value of an output such that it will cost more than its value in fees at this fee rate to spend it. (default: %s)", CURRENCY_UNIT, FormatMoney(DUST_RELAY_TX_FEE)), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-acceptstalefeeestimates", strprintf("Read fee estimates even if they are stale (%sdefault: %u) fee estimates are considered stale if they are %s hours old", "regtest only; ", DEFAULT_ACCEPT_STALE_FEE_ESTIMATES, Ticks<std::chrono::hours>(MAX_FILE_AGE)), ArgsManager::ALLOW_ANY | ArgsManager::DEBUG_ONLY, OptionsCategory::DEBUG_TEST);
     argsman.AddArg("-bytespersigop", strprintf("Equivalent bytes per sigop in transactions for relay and mining (default: %u)", DEFAULT_BYTES_PER_SIGOP), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
-    argsman.AddArg("-datacarrier", strprintf("Relay and mine data carrier transactions (default: %u)", DEFAULT_ACCEPT_DATACARRIER), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
+    argsman.AddArg("-datacarrier", strprintf("(DEPRECATED) Relay and mine data carrier transactions (default: %u)", DEFAULT_ACCEPT_DATACARRIER), ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
     argsman.AddArg("-datacarriersize",
-                   strprintf("Relay and mine transactions whose data-carrying raw scriptPubKeys in aggregate "
+                   strprintf("(DEPRECATED) Relay and mine transactions whose data-carrying raw scriptPubKeys in aggregate "
                              "are of this size or less, allowing multiple outputs (default: %u)",
                              MAX_OP_RETURN_RELAY),
                    ArgsManager::ALLOW_ANY, OptionsCategory::NODE_RELAY);
@@ -875,6 +875,10 @@ bool AppInitParameterInteraction(const ArgsManager& args)
         InitWarning(_("Option '-checkpoints' is set but checkpoints were removed. This option has no effect."));
     }
 
+    if (args.IsArgSet("-datacarriersize") || args.IsArgSet("-datacarrier")) {
+        InitWarning(_("Options '-datacarrier' or '-datacarriersize' are set but are marked as deprecated. They will be removed in a future version."));
+    }
+
     // Error if network-specific options (-addnode, -connect, etc) are
     // specified in default section of config file, but not overridden
     // on the command line or in this chain's section of the config file.

test/functional/mempool_datacarrier.py

@@ -89,6 +89,17 @@ def run_test(self):
         self.test_null_data_transaction(node=self.nodes[2], data=one_byte, success=True)
         self.test_null_data_transaction(node=self.nodes[3], data=one_byte, success=False)
 
+        # Clean shutdown boilerplate due to deprecation
+        self.expected_stderr = [
+            "",  # node 0 has no deprecated options
+            "Warning: Options '-datacarrier' or '-datacarriersize' are set but are marked as deprecated. They will be removed in a future version.",
+            "Warning: Options '-datacarrier' or '-datacarriersize' are set but are marked as deprecated. They will be removed in a future version.",
+            "Warning: Options '-datacarrier' or '-datacarriersize' are set but are marked as deprecated. They will be removed in a future version.",
+        ]
+
+        for i in range(self.num_nodes):
+            self.stop_node(i, expected_stderr=self.expected_stderr[i])
+
 
 if __name__ == '__main__':
     DataCarrierTest(__file__).main()