Editor context actions - Fix: "Check for (not) null" is only offered if the type of the assigned expression is reference type. Now the actions is offered pretty much only in the situations where it makes sense.

src/AddIns/Misc/SharpRefactoring/Project/Src/ContextActions/CheckAssignmentCache.cs

@@ -17,16 +17,19 @@ namespace SharpRefactoring.ContextActions
 	{
 		public void Initialize(EditorContext context)
 		{
+			this.context = context;
 			this.VariableName = GetVariableName(context);
 			this.CodeGenerator = GetCodeGenerator(context);
 			this.Element = GetElement(context);
 			this.ElementRegion = (Element == null) ? DomRegion.Empty : DomRegion.FromLocation(Element.StartLocation, Element.EndLocation);
 		}
 		
+		EditorContext context;
+		
 		public bool IsActionAvailable
 		{
 			get {
-				return !string.IsNullOrEmpty(this.VariableName) && (this.CodeGenerator != null);
+				return !string.IsNullOrEmpty(this.VariableName) && (this.CodeGenerator != null) && (this.context.CurrentLine.Text.Contains(";"));
 			}
 		}
 		
@@ -76,7 +79,7 @@ namespace SharpRefactoring.ContextActions
 			var identifier = assignment.Left as IdentifierExpression;
 			if (identifier == null)
 				return null;
-			if (!ExpressionCanBeNull(assignment.Right))
+			if ((!ExpressionCanBeNull(assignment.Right)) || ExpressionIsValueType(assignment.Right))
 				// don't offer action where it makes no sense
 				return null;
 			return identifier.Identifier;
@@ -89,12 +92,19 @@ namespace SharpRefactoring.ContextActions
 			if (declaration.Variables.Count != 1)
 				return null;
 			VariableDeclaration varDecl = declaration.Variables[0];
-			if (!ExpressionCanBeNull(varDecl.Initializer))
+			if (!ExpressionCanBeNull(varDecl.Initializer) || ExpressionIsValueType(varDecl.Initializer))
 				// don't offer action where it makes no sense
 				return null;
 			return varDecl.Name;
 		}
 		
+		bool ExpressionIsValueType(Expression expr)
+		{
+			ResolveResult rr = this.context.ResolveExpression(expr);
+			if (rr == null) return false;	// when cannot resolve the assignment right, still offer the action
+			return (rr.ResolvedType != null && rr.ResolvedType.IsReferenceType == false);
+		}
+		
 		bool ExpressionCanBeNull(Expression expr)
 		{
 			if (expr == null) return false;

src/AddIns/Misc/SharpRefactoring/Project/Src/ContextActions/CheckMemberNotNull.cs

@@ -46,6 +46,16 @@ namespace SharpRefactoring.ContextActions
 				//this.targetExpr is IdentifierExpression;		// "don't offer the action for just a.b, only for a.b.c"
 		}
 		
+		public override void Execute(EditorContext context)
+		{
+			var conditionExpr = BuildCondition(this.targetExpr);
+			if (conditionExpr == null)
+				return;
+			var ifExpr = new IfElseStatement(conditionExpr, new BlockStatement());
+			
+			context.Editor.InsertCodeBefore(this.currentExpr, ifExpr);
+		}
+		
 		/// <summary>
 		/// Gets "a.b" from "a.b.c"
 		/// </summary>
@@ -57,16 +67,6 @@ namespace SharpRefactoring.ContextActions
 			return null;
 		}
 		
-		public override void Execute(EditorContext context)
-		{
-			var conditionExpr = BuildCondition(this.targetExpr);
-			if (conditionExpr == null)
-				return;
-			var ifExpr = new IfElseStatement(conditionExpr, new BlockStatement());
-			
-			context.Editor.InsertCodeBefore(this.currentExpr, ifExpr);
-		}
-		
 		/// <summary>
 		/// Turns "(a.b as T).d.e" into "(a != null) && (a.b is T) && ((a.b as T).d != null)"
 		/// </summary>

src/Main/Base/Project/Src/Services/RefactoringService/ContextActions/EditorContext.cs

@@ -104,6 +104,12 @@ namespace ICSharpCode.SharpDevelop.Refactoring
 //			DebugLog();
 		}
 		
+		public ResolveResult ResolveExpression(Expression expression)
+		{
+			ExpressionResult expr = GetExpressionAt(this.Editor, expression.EndLocation.Line, expression.EndLocation.Column);
+			return ResolveExpression(expr, this.Editor, expression.EndLocation.Line, expression.EndLocation.Column);
+		}
+		
 		/// <summary>
 		/// Do not call from your Context actions - used by SharpDevelop.
 		/// Sets contents of editor context to null to prevent memory leaks. Used in case users implementing IContextActionProvider
@@ -236,10 +242,15 @@ namespace ICSharpCode.SharpDevelop.Refactoring
 
 		ExpressionResult GetExpressionAtCaret(ITextEditor editor)
 		{
-			ExpressionResult expr = ParserService.FindFullExpression(CaretLine, CaretColumn, editor.Document, editor.FileName);
+			return GetExpressionAt(editor, this.CaretLine, this.CaretColumn);
+		}
+		
+		ExpressionResult GetExpressionAt(ITextEditor editor, int caretLine, int caretColumn)
+		{
+			ExpressionResult expr = ParserService.FindFullExpression(caretLine, caretColumn, editor.Document, editor.FileName);
 			// if no expression, look one character back (works better with method calls - Foo()(*caret*))
-			if (string.IsNullOrWhiteSpace(expr.Expression) && CaretColumn > 1)
+			if (string.IsNullOrWhiteSpace(expr.Expression) && caretColumn > 1)
-				expr = ParserService.FindFullExpression(CaretLine, CaretColumn - 1, editor.Document, editor.FileName);
+				expr = ParserService.FindFullExpression(caretLine, caretColumn - 1, editor.Document, editor.FileName);
 			return expr;
 		}