#4353 Config.WithFallback is acting inconsistently

src/core/Akka.Cluster.Tests.MultiNode/Bugfix4353Specs.cs

@@ -0,0 +1,146 @@
+using System;
+using System.Linq;
+using System.Collections.Generic;
+using System.Threading;
+
+using Akka.Actor;
+using Akka.Cluster.TestKit;
+using Akka.Configuration;
+using Akka.Remote.TestKit;
+using Akka.TestKit;
+
+namespace Akka.Cluster.Tests.MultiNode
+{
+    public class Bugfix4353Spec : MultiNodeClusterSpec
+    {
+        protected RoleName First;
+        protected RoleName Second;
+        protected RoleName Third;
+
+        public Bugfix4353Spec() : this(new Bugfix4353SpecsConfig())
+        {
+        }
+
+        protected Bugfix4353Spec(Bugfix4353SpecsConfig config) : base(config, typeof(Bugfix4353Spec))
+        {
+            First = config.First;
+            Second = config.Second;
+            Third = config.Third;
+        }
+
+        [MultiNodeFact]
+        public void Bugfix4353Spec_Cluster_of_3_must_reach_cnovergence()
+        {
+            AwaitClusterUp(First, Second, Third);
+            EnterBarrier("after-1");
+        }
+    }
+
+    public class Bugfix4353SpecsConfig : MultiNodeConfig
+    {
+        private static readonly string[] Hocons =
+        {
+@"akka : {
+  actor : {
+    provider : cluster 
+  }
+}",
+
+@"akka : {
+  stdout-loglevel : INFO
+  loglevel : INFO 
+  log-config-on-start : on 
+  loggers : [""Akka.Event.DefaultLogger""],
+  actor : {
+    debug : {
+      receive : on
+      autoreceive : on
+      lifecycle : on
+      event-stream : on
+      unhandled : on 
+    } 
+  } 
+}",
+
+@"akka : {
+  remote : {
+    dot-netty : {
+      tcp : {
+        log-transport : true
+        transport-class : ""Akka.Remote.Transport.DotNetty.TcpTransport, Akka.Remote""
+        transport-protocol : tcp
+        hostname : 0.0.0.0
+        public-hostname : localhost
+      } 
+    } 
+  } 
+}",
+
+@"akka : {
+  cluster : {
+    log-info : on
+    seed-nodes : [
+      ""akka.tcp://Bugfix4353Spec@localhost:5001"",
+      ""akka.tcp://Bugfix4353Spec@localhost:5002"",
+      ""akka.tcp://Bugfix4353Spec@localhost:5003""
+    ]
+    roles : [seed]
+    role : { } 
+  } 
+}"
+        };
+
+        public static Config Config
+        {
+            get
+            {
+                var config = ConfigurationFactory.Empty;
+
+                foreach (var hocon in Hocons)
+                {
+                    config = config.WithFallback(ConfigurationFactory.ParseString(hocon));
+                }
+                return config;
+            }
+        }
+
+        public readonly RoleName First;
+        public readonly RoleName Second;
+        public readonly RoleName Third;
+
+        public Bugfix4353SpecsConfig()
+        {
+
+            First = Role("first");
+            Second = Role("second");
+            Third = Role("third");
+
+            CommonConfig = MultiNodeClusterSpec.ClusterConfig(false);
+
+            NodeConfig(
+                new[] { First },
+                new[] {
+                    ConfigurationFactory
+                    .ParseString("akka.remote.dot-netty.tcp.port : 5001")
+                    .WithFallback(Config)
+                });
+
+            NodeConfig(
+                new[] { Second },
+                new[] {
+                    ConfigurationFactory
+                    .ParseString("akka.remote.dot-netty.tcp.port : 5002")
+                    .WithFallback(Config)
+                });
+
+            NodeConfig(
+                new[] { Third },
+                new[] {
+                    ConfigurationFactory
+                    .ParseString("akka.remote.dot-netty.tcp.port : 5003")
+                    .WithFallback(Config)
+                });
+
+        }
+    }
+}

src/core/Akka/Configuration/Hocon/HoconObject.cs

@@ -196,6 +196,8 @@ public void Merge(HoconObject other)
                     //if both values are objects, merge them
                     if (thisItem.IsObject() && otherItem.Value.IsObject())
                         thisItem.GetObject().Merge(otherItem.Value.GetObject());
+                    else
+                        modified.Add(new KeyValuePair<string, HoconValue>(otherItem.Key, otherItem.Value));
                 }
                 else
                 {
@@ -228,6 +230,8 @@ internal HoconObject MergeImmutable(HoconObject other)
                         mergedValue.AppendValue(mergedObject);
                         thisItems[otherItem.Key] = mergedValue;
                     }
+                    else
+                        thisItems[otherItem.Key] = otherItem.Value;
                 }
                 else
                 {