Implemented resharper disableing for redundant using directive.

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

@@ -159,7 +159,7 @@ namespace ICSharpCode.NRefactory.CSharp
 			}
 		}
 
-		bool IsSuppressed(TextLocation location)
+		protected bool IsSuppressed(TextLocation location)
 		{
 			return isDisabled || isGloballySuppressed || suppressedRegions.Any(r => r.IsInside(location));
 		}

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

@@ -41,7 +41,9 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 	                  Description = "Removes used declarations that are not required.",
 	                  Category = IssueCategories.Redundancies,
 	                  Severity = Severity.Hint,
-	                  IssueMarker = IssueMarker.GrayOut)]
+	                  IssueMarker = IssueMarker.GrayOut,
+	                  ResharperDisableKeyword = "RedundantUsingDirective"
+	)]
 	public class RedundantUsingIssue : ICodeIssueProvider
 	{
 		List<string> namespacesToKeep = new List<string>();
@@ -87,6 +89,8 @@ namespace ICSharpCode.NRefactory.CSharp.Refactoring
 			public override void VisitUsingDeclaration(UsingDeclaration usingDeclaration)
 			{
 				base.VisitUsingDeclaration(usingDeclaration);
+				if (IsSuppressed(usingDeclaration.StartLocation))
+					return;
 				var nrr = ctx.Resolve(usingDeclaration.Import) as NamespaceResolveResult;
 				if (nrr != null) {
 					isInUse[usingDeclaration] = IssueProvider.namespacesToKeep.Contains(nrr.NamespaceName);

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

@@ -135,5 +135,22 @@ class Bar
 			var issues = GetIssues (new RedundantUsingIssue (), input, out context);
 			Assert.AreEqual (0, issues.Count);
 		}
+
+		[Test]
+		public void TestResharperDisableRestore ()
+		{
+			var input = @"// ReSharper disable RedundantUsingDirective
+using System;
+// ReSharper restore RedundantUsingDirective
+using System.IO;
+
+class Foo
+{
+}";
+
+			TestRefactoringContext context;
+			var issues = GetIssues (new RedundantUsingIssue (), input, out context);
+			Assert.AreEqual (1, issues.Count);
+		}
 	}
 }