Do not put an equals and quotes when completing an xml attribute if present

src/EditorFeatures/CSharpTest/Completion/CompletionProviders/XmlDocumentationCommentCompletionProviderTests.cs

@@ -760,6 +760,35 @@ static void Goo()
                 """, "cref", "langword", "href");
         }
 
+        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/72259")]
+        public async Task SeeAttributeNames2()
+        {
+            var text = """
+                class C
+                {
+                    /// <summary>
+                    /// <see l$$=""/>
+                    /// </summary>
+                    static void Goo()
+                    {
+                    }
+                }
+                """;
+            var expected = """
+                class C
+                {
+                    /// <summary>
+                    /// <see langword=""/>
+                    /// </summary>
+                    static void Goo()
+                    {
+                    }
+                }
+                """;
+
+            await VerifyProviderCommitAsync(text, "langword", expected, null);
+        }
+
         [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/37504")]
         public async Task SeeAlsoAttributeNames()
         {
@@ -1015,23 +1044,6 @@ void Goo() { }
             await VerifyItemExistsAsync(text, "langword");
         }
 
-        [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/11489")]
-        public async Task AttributeValueOnQuote()
-        {
-            var text = """
-                class C
-                {
-                    /// <summary>
-                    /// <see langword="$$
-                    /// </summary>
-                    static void Goo()
-                    {
-                    }
-                }
-                """;
-            await VerifyItemExistsAsync(text, "await", usePreviousCharAsTrigger: true);
-        }
-
         [Fact, WorkItem("https://github.com/dotnet/roslyn/issues/757")]
         public async Task TermAndDescriptionInsideItem()
         {

src/EditorFeatures/Test2/IntelliSense/CSharpCompletionCommandHandlerTests_XmlDoc.vb

@@ -625,6 +625,54 @@ class c
             End Using
         End Function
 
+        <WpfTheory, CombinatorialData>
+        Public Async Function InvokeWithOpenAngleSeeCommitLangwordWithEqualsQuotes(showCompletionInArgumentLists As Boolean) As Task
+
+            Using state = TestStateFactory.CreateCSharpTestState(
+                <Document><![CDATA[
+class c
+{
+    /// <summary>
+    /// <see $$=""
+    /// </summary>
+    void goo() { }
+}
+            ]]></Document>, showCompletionInArgumentLists:=showCompletionInArgumentLists)
+
+                state.SendTypeChars("l")
+                state.SendInvokeCompletionList()
+                Await state.AssertSelectedCompletionItem(displayText:="langword")
+                state.SendReturn()
+
+                ' /// <see langword="$$"/>
+                Await state.AssertLineTextAroundCaret("    /// <see langword=""", """")
+            End Using
+        End Function
+
+        <WpfTheory, CombinatorialData>
+        Public Async Function InvokeWithOpenAngleSeeCommitLangwordWithSpaceEqualsQuotes(showCompletionInArgumentLists As Boolean) As Task
+
+            Using state = TestStateFactory.CreateCSharpTestState(
+                <Document><![CDATA[
+class c
+{
+    /// <summary>
+    /// <see $$ =""
+    /// </summary>
+    void goo() { }
+}
+            ]]></Document>, showCompletionInArgumentLists:=showCompletionInArgumentLists)
+
+                state.SendTypeChars("l")
+                state.SendInvokeCompletionList()
+                Await state.AssertSelectedCompletionItem(displayText:="langword")
+                state.SendReturn()
+
+                ' /// <see langword="$$"/>
+                Await state.AssertLineTextAroundCaret("    /// <see langword=""", """ =""""")
+            End Using
+        End Function
+
         <WpfTheory, CombinatorialData>
         Public Function InvokeWithNullKeywordCommitSeeLangword(showCompletionInArgumentLists As Boolean) As Task
             Return InvokeWithKeywordCommitSeeLangword("null", showCompletionInArgumentLists)

src/Features/CSharp/Portable/Completion/CompletionProviders/XmlDocCommentCompletionProvider.cs

@@ -85,7 +85,9 @@ public override bool IsInsertionTrigger(SourceText text, int characterPosition,
 
             if (IsAttributeNameContext(token, position, out var elementName, out var existingAttributes))
             {
-                return GetAttributeItems(elementName, existingAttributes);
+                var nextToken = token.GetNextToken();
+                return GetAttributeItems(elementName, existingAttributes,
+                    addEqualsAndQuotes: !nextToken.IsKind(SyntaxKind.EqualsToken) || nextToken.HasLeadingTrivia);
             }
 
             var wasTriggeredAfterSpace = trigger.Kind == CompletionTriggerKind.Insertion && trigger.Character == ' ';

src/Features/Core/Portable/Completion/Providers/AbstractDocCommentCompletionProvider.cs

@@ -113,10 +113,14 @@ private CompletionItem GetItem(string name)
         return CreateCompletionItem(name);
     }
 
-    protected IEnumerable<CompletionItem> GetAttributeItems(string tagName, ISet<string> existingAttributes)
+    protected IEnumerable<CompletionItem> GetAttributeItems(string tagName, ISet<string> existingAttributes, bool addEqualsAndQuotes)
     {
-        return s_attributeMap.Where(x => x.elementName == tagName && !existingAttributes.Contains(x.attributeName))
-                             .Select(x => CreateCompletionItem(x.attributeName, beforeCaretText: x.text, afterCaretText: "\""));
+        return s_attributeMap
+            .Where(x => x.elementName == tagName && !existingAttributes.Contains(x.attributeName))
+            .Select(x => CreateCompletionItem(
+                x.attributeName,
+                beforeCaretText: addEqualsAndQuotes ? x.text : x.text[..^2],
+                afterCaretText: addEqualsAndQuotes ? "\"" : ""));
     }
 
     protected IEnumerable<CompletionItem> GetAlwaysVisibleItems()
@@ -279,6 +283,13 @@ public override async Task<CompletionChange> GetChangeAsync(Document document, C
         var replacementText = beforeCaretText;
         var newPosition = replacementSpan.Start + beforeCaretText.Length;
 
+        if (text.Length > replacementSpan.End + 1
+            && text[replacementSpan.End] == '='
+            && text[replacementSpan.End + 1] == '"')
+        {
+            newPosition += 2;
+        }
+
         if (commitChar.HasValue && !char.IsWhiteSpace(commitChar.Value) && commitChar.Value != replacementText[^1])
         {
             // include the commit character

src/Features/VisualBasic/Portable/Completion/CompletionProviders/XmlDocCommentCompletionProvider.vb

@@ -332,7 +332,7 @@
 
         Private Function GetAttributes(tagName As String, attributes As SyntaxList(Of XmlNodeSyntax)) As IEnumerable(Of CompletionItem)
             Dim existingAttributeNames = attributes.Select(AddressOf GetAttributeName).WhereNotNull().ToSet()
-            Return GetAttributeItems(tagName, existingAttributeNames)
+            Return GetAttributeItems(tagName, existingAttributeNames, addEqualsAndQuotes := false)
         End Function
 
         Private Shared Function GetAttributeName(node As XmlNodeSyntax) As String