Fix IDISP013 using declaration in outer scope regression

Author: Bouke

IDisposableAnalyzers.Test/IDISP013AwaitInUsingTests/Diagnostics.cs

@@ -86,6 +86,35 @@ private static async ValueTask<int> InnerAsync()
         RoslynAssert.Diagnostics(Analyzer, ExpectedDiagnostic, code);
     }
 
+    [Test]
+    public static void UsingDeclarationInner()
+    {
+        var code = @"
+namespace N
+{
+    using System.Threading.Tasks;
+
+    public static class C
+    {
+        public static ValueTask<int> MAsync()
+        {
+            using var file = System.IO.File.OpenRead(string.Empty);
+            while (true)
+            {
+                return ↓InnerAsync();
+            }
+        }
+
+        private static async ValueTask<int> InnerAsync()
+        {
+            await Task.Delay(10).ConfigureAwait(false);
+            return 1;
+        }
+    }
+}";
+        RoslynAssert.Diagnostics(Analyzer, ExpectedDiagnostic, code);
+    }
+
     [Test]
     public static void LocalTask()
     {

IDisposableAnalyzers/Analyzers/ReturnValueAnalyzer.cs

@@ -146,14 +146,16 @@ private static bool IsInUsing(SyntaxNode node)
             {
                 if (statement.SpanStart >= node.SpanStart)
                 {
-                    return false;
+                    break;
                 }
 
                 if (statement is LocalDeclarationStatementSyntax { UsingKeyword.ValueText: "using" })
                 {
                     return true;
                 }
             }
+
+            return node.Parent != null && IsInUsing(node.Parent);
         }
 
         return false;