Fix SA1514: Do not report when documenting types declared in the global namespace

StyleCop.Analyzers/StyleCop.Analyzers.Test/LayoutRules/SA1514UnitTests.cs

@@ -1151,5 +1151,23 @@ public enum TestEnum
 
             await VerifyCSharpFixAsync(testCode, expected, fixedCode, CancellationToken.None).ConfigureAwait(false);
         }
+
+        [Fact]
+        [WorkItem(3849, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/3849")]
+        public async Task TestClassInGlobalNamespaceAsync()
+        {
+            var testCode = @"
+/// <summary>
+/// X.
+/// </summary>
+public class TestClass
+{
+}
+";
+
+            var expected = DiagnosticResult.EmptyDiagnosticResults;
+
+            await VerifyCSharpDiagnosticAsync(testCode, expected, CancellationToken.None).ConfigureAwait(false);
+        }
     }
 }

StyleCop.Analyzers/StyleCop.Analyzers/LayoutRules/SA1514ElementDocumentationHeaderMustBePrecededByBlankLine.cs

@@ -170,6 +170,18 @@ private static void HandleDeclaration(SyntaxNodeAnalysisContext context)
                     // no leading blank line necessary at start of scope.
                     return;
                 }
+
+                // Logic to handle global namespace case
+                if (prevToken.IsKind(SyntaxKind.None))
+                {
+                    // Check if the node is the first non-trivia element in the file
+                    var firstToken = context.Node.SyntaxTree.GetRoot().GetFirstToken();
+                    if (firstToken == context.Node.GetFirstToken())
+                    {
+                        // Node is the first element in the global namespace
+                        return;
+                    }
+                }
             }
 
             context.ReportDiagnostic(Diagnostic.Create(Descriptor, GetDiagnosticLocation(documentationHeader)));