Warn on unknown rw_settings

src/util/system.cpp

@@ -426,6 +426,14 @@ bool ArgsManager::ReadSettingsFile(std::vector<std::string>* errors)
         SaveErrors(read_errors, errors);
         return false;
     }
+    for (const auto& setting : m_settings.rw_settings) {
+        std::string section;
+        std::string key = setting.first;
+        (void)InterpretOption(section, key, /* value */ {}); // Split setting key into section and argname
+        if (!GetArgFlags('-' + key)) {
+            LogPrintf("Ignoring unknown rw_settings value %s\n", setting.first);
+        }
+    }
     return true;
 }
 

test/functional/feature_settings.py

@@ -30,19 +30,25 @@ class SettingsTest(BitcoinTestFramework):
 
         # Assert settings are parsed and logged
         with settings.open("w") as fp:
-            json.dump({"string": "string", "num": 5, "bool": True, "null": None, "list": [6,7]}, fp)
+            json.dump({"string": "string", "num": 5, "bool": True, "null": None, "list": [6, 7]}, fp)
         with node.assert_debug_log(expected_msgs=[
+                'Ignoring unknown rw_settings value bool',
+                'Ignoring unknown rw_settings value list',
+                'Ignoring unknown rw_settings value null',
+                'Ignoring unknown rw_settings value num',
+                'Ignoring unknown rw_settings value string',
                 'Setting file arg: string = "string"',
                 'Setting file arg: num = 5',
                 'Setting file arg: bool = true',
                 'Setting file arg: null = null',
-                'Setting file arg: list = [6,7]']):
+                'Setting file arg: list = [6,7]',
+        ]):
             self.start_node(0)
             self.stop_node(0)
 
         # Assert settings are unchanged after shutdown
         with settings.open() as fp:
-            assert_equal(json.load(fp), {"string": "string", "num": 5, "bool": True, "null": None, "list": [6,7]})
+            assert_equal(json.load(fp), {"string": "string", "num": 5, "bool": True, "null": None, "list": [6, 7]})
 
         # Test invalid json
         with settings.open("w") as fp: