Fix handling of consecutive empty elements

Author: sharwell

StyleCop.Analyzers/StyleCop.Analyzers.Test/DocumentationRules/SA1629UnitTests.cs

@@ -336,6 +336,47 @@ public interface ITest
             await this.VerifyCSharpFixAsync(testCode, fixedTestCode).ConfigureAwait(false);
         }
 
+        [Fact]
+        [WorkItem(2680, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/2680")]
+        public async Task TestReportingAfterTwoEmptyElementsAsync()
+        {
+            var testCode = @"
+/// <summary>
+/// Test interface <see cref=""ITest""/> <see cref=""ITest""/>
+/// </summary>
+public interface ITest
+{
+    /// <summary>
+    /// Test method <see cref=""Method""/><see cref=""Method""/>
+    /// </summary>
+    void Method();
+}
+";
+
+            var fixedTestCode = @"
+/// <summary>
+/// Test interface <see cref=""ITest""/> <see cref=""ITest""/>.
+/// </summary>
+public interface ITest
+{
+    /// <summary>
+    /// Test method <see cref=""Method""/><see cref=""Method""/>.
+    /// </summary>
+    void Method();
+}
+";
+
+            DiagnosticResult[] expected =
+            {
+                this.CSharpDiagnostic().WithLocation(3, 59),
+                this.CSharpDiagnostic().WithLocation(8, 61),
+            };
+
+            await this.VerifyCSharpDiagnosticAsync(testCode, expected, CancellationToken.None).ConfigureAwait(false);
+            await this.VerifyCSharpDiagnosticAsync(fixedTestCode, EmptyDiagnosticResults, CancellationToken.None).ConfigureAwait(false);
+            await this.VerifyCSharpFixAsync(testCode, fixedTestCode).ConfigureAwait(false);
+        }
+
         [Fact]
         [WorkItem(2679, "https://github.com/DotNetAnalyzers/StyleCopAnalyzers/issues/2679")]
         public async Task TestElementsThatDoNotRequirePeriodsAsync()

StyleCop.Analyzers/StyleCop.Analyzers/DocumentationRules/SA1629DocumentationTextMustEndWithAPeriod.cs

@@ -110,7 +110,7 @@ protected override void HandleXmlElement(SyntaxNodeAnalysisContext context, bool
                     {
                         // If a diagnostic gets reported for the element, place the diagnostic after the last inline
                         // element.
-                        reportingLocation = xmlElement.Content[i].Span.End;
+                        reportingLocation = reportingLocation ?? xmlElement.Content[i].Span.End;
                     }
                 }
             }