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()
         {

src/EditorFeatures/Test2/IntelliSense/CSharpCompletionCommandHandlerTests_XmlDoc.vb

@@ -625,6 +625,76 @@ class c
             End Using
         End Function
 
+        <WpfTheory, CombinatorialData>
+        Public Async Function InvokeWithOpenAngleSeeCommitSeeWithEqualsQuotes(showCompletionInArgumentLists As Boolean) As Task
+            Using state = TestStateFactory.CreateCSharpTestState(
+                <Document><![CDATA[
+class c
+{
+    /// <summary>
+    /// <see $$=""
+    /// </summary>
+    void goo() { }
+}
+            ]]></Document>, showCompletionInArgumentLists:=showCompletionInArgumentLists)
+
+                state.SendInvokeCompletionList()
+                state.AssertItemsInOrder({"!--", "![CDATA[", "inheritdoc", "see", "seealso"})
+                state.SendTypeChars("see")
+                Await state.AssertSelectedCompletionItem(displayText:="see")
+                state.SendReturn()
+
+                ' /// <see <see cref=""/$$>=""
+                Await state.AssertLineTextAroundCaret("    /// <see <see cref=""""/", ">=""""")
+            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/EditorFeatures/Test2/IntelliSense/VisualBasicCompletionCommandHandlerTests_XmlDoc.vb

@@ -549,6 +549,29 @@ End Class
             End Using
         End Function
 
+        <WpfFact>
+        Public Async Function InvokeWithOpenAngleSeeCommitSeeWithEqualsQuotes() As Task
+            Using state = TestStateFactory.CreateVisualBasicTestState(
+                <Document><![CDATA[
+Class C
+    ''' <summary>
+    ''' <see $$=""
+    ''' </summary>
+    Sub Goo()
+    End Sub
+End Class
+            ]]></Document>)
+
+                state.SendTypeChars("l")
+                Await state.AssertCompletionSession()
+                Await state.AssertSelectedCompletionItem(displayText:="langword")
+                state.SendReturn()
+
+                ' ''' <see langword="$$"
+                Await state.AssertLineTextAroundCaret("    ''' <see langword=""", """")
+            End Using
+        End Function
+
         <WpfFact>
         Public Async Function InvokeWithOpenAngleCommitSeeOnCloseAngle() As Task
 

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

@@ -237,20 +237,20 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Completion.Providers
 
                 If targetToken.IsChildToken(Function(n As XmlNameSyntax) n.LocalName) AndAlso targetToken.Parent Is tagNameSyntax Then
                     ' <exception |
-                    items.AddRange(GetAttributes(tagName, tagAttributes))
+                    items.AddRange(GetAttributes(token, tagName, tagAttributes))
                 End If
 
                 '<exception a|
                 If targetToken.IsChildToken(Function(n As XmlNameSyntax) n.LocalName) AndAlso targetToken.Parent.IsParentKind(SyntaxKind.XmlAttribute) Then
                     ' <exception |
-                    items.AddRange(GetAttributes(tagName, tagAttributes))
+                    items.AddRange(GetAttributes(token, tagName, tagAttributes))
                 End If
 
                 '<exception a=""|
                 If (targetToken.IsChildToken(Function(s As XmlStringSyntax) s.EndQuoteToken) AndAlso targetToken.Parent.IsParentKind(SyntaxKind.XmlAttribute)) OrElse
                     targetToken.IsChildToken(Function(a As XmlNameAttributeSyntax) a.EndQuoteToken) OrElse
                     targetToken.IsChildToken(Function(a As XmlCrefAttributeSyntax) a.EndQuoteToken) Then
-                    items.AddRange(GetAttributes(tagName, tagAttributes))
+                    items.AddRange(GetAttributes(token, tagName, tagAttributes))
                 End If
 
                 ' <param name="|"
@@ -330,9 +330,11 @@ Namespace Microsoft.CodeAnalysis.VisualBasic.Completion.Providers
             Return TryCast(attribute, XmlNameAttributeSyntax)?.Reference?.Identifier.ValueText
         End Function
 
-        Private Function GetAttributes(tagName As String, attributes As SyntaxList(Of XmlNodeSyntax)) As IEnumerable(Of CompletionItem)
+        Private Function GetAttributes(token As SyntaxToken, tagName As String, attributes As SyntaxList(Of XmlNodeSyntax)) As IEnumerable(Of CompletionItem)
             Dim existingAttributeNames = attributes.Select(AddressOf GetAttributeName).WhereNotNull().ToSet()
-            Return GetAttributeItems(tagName, existingAttributeNames)
+            Dim nextToken = token.GetNextToken()
+            Return GetAttributeItems(tagName, existingAttributeNames,
+                                     addEqualsAndQuotes:=Not nextToken.IsKind(SyntaxKind.EqualsToken) Or nextToken.HasLeadingTrivia)
         End Function
 
         Private Shared Function GetAttributeName(node As XmlNodeSyntax) As String