fixed: #390; fixed excessive memory in ImTools.Match for 2 item arrays

Author: dadhi

src/DryIoc/Container.cs

@@ -1079,7 +1079,7 @@ internal static void TryThrowUnableToResolve(Request request)
             str = request.Container
                 .GetAllServiceFactories(request.ServiceType, bothClosedAndOpenGenerics: true)
                 .Aggregate(str, (s, x) => s
-                    .Append(x.Value.Reuse?.CanApply(request) ?? true ? "  " : "  without matching scope ")
+                    .Append((x.Value.Reuse?.CanApply(request) ?? true) ? "  " : "  without matching scope ")
                     .Print(x));
 
             if (str.Length != 0)
@@ -1171,8 +1171,9 @@ Factory IContainer.GetServiceFactoryOrDefault(Request request)
             var factories = entry == null ? null
                 : entry is Factory factory ? new KV<object, Factory>(DefaultKey.Value, factory).One()
                 : entry.To<FactoriesEntry>().Factories
-                       .Visit(new List<KV<object, Factory>>(2), (x, list) => list.Add(KV.Of(x.Key, x.Value))).ToArray(); // todo: optimize - we may not need ToArray here
- 
+                    .Visit(new List<KV<object, Factory>>(2), (x, list) => list.Add(KV.Of(x.Key, x.Value))).ToArray() // todo: optimize - we may not need ToArray here
+                    .Match(x => x.Value != null); // filter out the Unregistered factories (see #390)
+
             if (!factories.IsNullOrEmpty()) // check for the additional (not the fallback) factories, because we have the standard factories
             {
                 if (Rules.HasDynamicRegistrationProvider(
@@ -1456,9 +1457,10 @@ IEnumerable<KV<object, Factory>> IContainer.GetAllServiceFactories(Type serviceT
         private static IEnumerable<KV<object, Factory>> GetRegistryEntryKeyFactoryPairs(object entry) =>
             entry == null
                 ? Empty<KV<object, Factory>>()
-                : entry is Factory ? new[] { new KV<object, Factory>(DefaultKey.Value, (Factory)entry) }
+                : entry is Factory f ? new[] { new KV<object, Factory>(DefaultKey.Value, f) }
                 // todo: optimize
-                : entry.To<FactoriesEntry>().Factories.Visit(new List<KV<object, Factory>>(), (x, l) => l.Add(KV.Of(x.Key, x.Value))).ToArray();
+                : entry.To<FactoriesEntry>().Factories.Visit(new List<KV<object, Factory>>(), (x, l) => l.Add(KV.Of(x.Key, x.Value))).ToArray()
+                       .Match(x => x.Value != null); // filter out the Unregistered factories
 
         Expression IContainer.GetDecoratorExpressionOrDefault(Request request)
         {
@@ -2709,19 +2711,23 @@ private Registry UnregisterServiceFactory(Type serviceType, object serviceKey =
 
                 var registry = WithServices(services);
 
-                var removedFactory = removed as Factory;
-                if (removedFactory != null)
-                    registry.DropFactoryCache(removedFactory, hash, serviceType, serviceKey);
+                if (removed is Factory f)
+                    registry.DropFactoryCache(f, hash, serviceType, serviceKey);
+                else if (removed is Factory[] fs)
+                    foreach (var rf in fs)
+                        registry.DropFactoryCache(rf, hash, serviceType, serviceKey);
                 else
-                    (removed as Factory[] ??
-                     ((FactoriesEntry)removed).Factories.Enumerate().Select(f => f.Value).ToArray())
-                        .ForEach(x => registry.DropFactoryCache(x, hash, serviceType, serviceKey));
+                    foreach (var e in ((FactoriesEntry)removed).Factories.Enumerate())
+                        registry.DropFactoryCache(e.Value, hash, serviceType, serviceKey);
 
                 return registry;
             }
 
             internal void DropFactoryCache(Factory factory, int hash, Type serviceType, object serviceKey = null)
             {
+                if (factory == null)
+                    return; // filter out Unregistered factory (see #390)
+
                 if (DefaultFactoryCache != null || KeyedFactoryCache != null)
                 {
                     if (factory.FactoryGenerator == null)

src/DryIoc/ImTools.cs

@@ -1874,7 +1874,7 @@ public static T[] Match<T>(this T[] source, Func<T, bool> condition)
             {
                 var condition0 = condition(source[0]);
                 var condition1 = condition(source[1]);
-                return condition0 && condition1 ? new[] { source[0], source[1] }
+                return condition0 && condition1 ? source
                     : condition0 ? new[] { source[0] }
                     : condition1 ? new[] { source[1] }
                     : Empty<T>();
@@ -1913,7 +1913,7 @@ public static T[] Match<T, S>(this T[] source, S state, Func<S, T, bool> conditi
             {
                 var condition0 = condition(state, source[0]);
                 var condition1 = condition(state, source[1]);
-                return condition0 && condition1 ? new[] { source[0], source[1] }
+                return condition0 && condition1 ? source
                     : condition0 ? new[] { source[0] }
                     : condition1 ? new[] { source[1] }
                     : Empty<T>();

test/DryIoc.IssuesTests/GHIssue390_NullReferenceException_on_Unregister.cs

@@ -0,0 +1,44 @@
+using NUnit.Framework;
+using System.Linq;
+
+namespace DryIoc.IssuesTests
+{
+    [TestFixture]
+    public class GHIssue390_NullReferenceException_on_Unregister : ITest
+    {
+        public int Run() 
+        { 
+            Test1();
+            return 1;
+        }
+
+        [Test]
+        public void Test1()
+        {
+            var implementationType1 = typeof(A);
+            var implementationType2 = typeof(B);
+            var interfaceType       = typeof(ITargetInterface);
+
+            var container = new Container();
+            container.Register(interfaceType, implementationType1, serviceKey: "foo");
+            container.Register(interfaceType, implementationType2, serviceKey: "bar");
+
+            container.Unregister(interfaceType, serviceKey: "foo");
+
+            Assert.Throws<ContainerException>(() => 
+                container.Resolve(interfaceType, "foo"));
+
+            var x = container.Resolve(interfaceType, "foo", IfUnresolved.ReturnDefault);
+            Assert.IsNull(x);
+
+            var a = container.ResolveMany(interfaceType, ResolveManyBehavior.AsFixedArray);
+            Assert.IsInstanceOf<B>(a.Single());
+
+            container.ClearCache(interfaceType);
+        }
+
+        interface ITargetInterface {}
+        class A : ITargetInterface {}
+        class B : ITargetInterface {}
+    }
+}