[CodeIssues] Updating the NoDefaultConstructorIssue to ignore inaccessible constructors and to only look at the direct base type. I also updated the issue text to contain the compiler error number, and altered the way that the string was formatted so that the format string is passed into TranslateString.

ICSharpCode.NRefactory.CSharp/Refactoring/CodeIssues/NoDefaultConstructorIssue.cs

@@ -2,6 +2,7 @@ using System.Collections.Generic;
 using System.Linq;
 using ICSharpCode.NRefactory.Semantics;
 using ICSharpCode.NRefactory.TypeSystem;
+using ICSharpCode.NRefactory.CSharp.Resolver;
 
 namespace ICSharpCode.NRefactory.CSharp.Refactoring
 {
@@ -31,7 +32,7 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 			public override void VisitTypeDeclaration(TypeDeclaration declaration)
 			{
 				var result = ctx.Resolve(declaration) as TypeResolveResult;
-				var baseType = result.Type.GetNonInterfaceBaseTypes().FirstOrDefault(t => !t.IsKnownType(KnownTypeCode.Object) && !object.Equals(t, result.Type));
+				var baseType = result.Type.DirectBaseTypes.FirstOrDefault(t => !t.IsKnownType(KnownTypeCode.Object) && t.Kind != TypeKind.Interface);
 
 				if (baseType != null)
 				{
@@ -39,8 +40,9 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 					this.baseType = baseType;
 
 					var baseConstructor = baseType.GetConstructors(c => c.Parameters.Count == 0).FirstOrDefault();
+					var memberLookup = new MemberLookup(result.Type.GetDefinition(), ctx.Compilation.MainAssembly, false);
 
-					if (baseConstructor == null) {
+					if (baseConstructor == null || !memberLookup.IsAccessible(baseConstructor, true)) {
 						var constructor = result.Type.GetConstructors(f => !f.IsSynthetic).FirstOrDefault();
 
 						if (constructor == null) {
@@ -80,9 +82,9 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 			private void AddIssue(AstNode node, IType baseClass, int argumentCount = 0)
 			{
 				var identifier = node.GetChildByRole(Roles.Identifier);
-				var errorMessage = string.Format("The type '{0}' does not contain a constructor that takes '{1}' arguments", baseClass.FullName, argumentCount);
-
-				this.AddIssue(identifier, ctx.TranslateString(errorMessage));
+				this.AddIssue(
+					identifier,
+					string.Format(ctx.TranslateString("CS1729: The type '{0}' does not contain a constructor that takes '{1}' arguments"), baseType.Name, argumentCount));
 			}
 		}
 	}

ICSharpCode.NRefactory.Tests/CSharp/CodeIssues/NoDefaultConstructorIssueTests.cs

@@ -100,6 +100,43 @@ class ChildClass : BaseClass
 
 			Test<NoDefaultConstructorIssue>(testInput, 1);
 		}
+
+		[Test]
+		public void ShouldOnlyLookAtDirectBaseClasses()
+		{
+			var testInput =
+@"class TopLevelClass
+{
+	public TopLevelClass(string test) {}
+}
+
+class BaseClass : TopLevelClass
+{
+	public BaseClass() : base(""hello"") {}
+}
+
+class ChildClass : BaseClass
+{
+}";
+
+			Test<NoDefaultConstructorIssue>(testInput, 0);
+		}
+
+		[Test]
+		public void ShouldReturnAnIssueIfBaseConstructorIsPrivate()
+		{
+			var testInput =
+@"class BaseClass
+{
+	private BaseClass() {}
+}
+
+class ChildClass : BaseClass
+{
+}";
+
+			Test<NoDefaultConstructorIssue>(testInput, 1);
+		}
 	}
 }