handle VB.Net to CS conversion set attribute Axis syntax; replace assignment with call

src/Libraries/NRefactory/Project/Src/PrettyPrinter/CSharp/CSharpOutputVisitor.cs

@@ -2403,6 +2403,11 @@ namespace ICSharpCode.NRefactory.PrettyPrinter
 
         public override object TrackedVisitXmlMemberAccessExpression(XmlMemberAccessExpression xmlMemberAccessExpression, object data)
         {
+            var parentAsAssignment = xmlMemberAccessExpression.Parent as AssignmentExpression;
+            var xmlMemberAccessExpressionOnLeftOfAssignment = parentAsAssignment != null && parentAsAssignment.Left == xmlMemberAccessExpression;
+
+            // only output identifier expression if we are not overriding assignment with method call
+            if(!(xmlMemberAccessExpression.AxisType == XmlAxisType.Attribute && xmlMemberAccessExpressionOnLeftOfAssignment))
                 xmlMemberAccessExpression.TargetObject.AcceptVisitor(this, data);
             
             switch (xmlMemberAccessExpression.AxisType)
@@ -2414,10 +2419,22 @@ namespace ICSharpCode.NRefactory.PrettyPrinter
                     outputFormatter.PrintText("\")");
                     break;
                 case XmlAxisType.Attribute:
+                    if (!xmlMemberAccessExpressionOnLeftOfAssignment)
+                    {
                         outputFormatter.PrintToken(Tokens.Dot);
                         outputFormatter.PrintText("Attribute(\"");
                         outputFormatter.PrintText(xmlMemberAccessExpression.Identifier);
                         outputFormatter.PrintText("\").Value");
+                    }
+                    else
+                    {
+                        // we need to convert assignment to method call
+                        return AstBuilder.ExpressionBuilder.Call(
+                            xmlMemberAccessExpression.TargetObject, 
+                            "SetAttributeValue", 
+                            new PrimitiveExpression(xmlMemberAccessExpression.Identifier), 
+                            parentAsAssignment.Right);
+                    }
                     break;
                 case XmlAxisType.Descendents:
                     outputFormatter.PrintToken(Tokens.Dot);
@@ -2502,7 +2519,12 @@ namespace ICSharpCode.NRefactory.PrettyPrinter
 		
 		public override object TrackedVisitAssignmentExpression(AssignmentExpression assignmentExpression, object data)
 		{
-			TrackVisit(assignmentExpression.Left, data);
+            var overrideExpression = TrackVisit(assignmentExpression.Left, data) as InvocationExpression;
+            if (overrideExpression != null)
+            {
+                TrackVisit(overrideExpression, data);
+                return null;
+            }
 			if (this.prettyPrintOptions.AroundAssignmentParentheses) {
 				outputFormatter.Space();
 			}

src/Libraries/NRefactory/Test/Output/CSharp/VBNetToCSharpConverterTest.cs

@@ -913,7 +913,6 @@ static bool InitStaticVariableHelper(Microsoft.VisualBasic.CompilerServices.Stat
 			TestStatement(@"Dim xml = <A>&quot;</A>",
 			              @"var xml = new XElement(""A"", ""\"""");");
 		}
-		
 
         [Test]
         public void XmlLINQDescendants()
@@ -935,12 +934,27 @@ static bool InitStaticVariableHelper(Microsoft.VisualBasic.CompilerServices.Stat
                           @"var value = someXml.Attribute(""attr"").Value;");
         }
 
+        [Test]
+        public void XmlLINQAttributeSetConstant()
+        {
+            TestStatement(@"someElement.@someAttr = 8",
+                          @"someElement.SetAttributeValue(""someAttr"", 8);");
+        }
+
+        [Test]
+        public void XmlLINQAttributeSetExpression()
+        {
+            TestStatement(@"someElement.@someAttr = string.Format(""{0}"", 19)",
+                          @"someElement.SetAttributeValue(""someAttr"", string.Format(""{0}"", 19));");
+        }
+
         [Test]
         public void LinqQueryWhereSelect()
         {
             TestStatement(@"Dim value = From value In values Where value = ""someValue"" Select value",
                           @"var value = from value in values where value == ""someValue"" select value;");
         }
+
 		[Test]
 		public void SD2_1500a()
 		{