Fixed MSBuild condition evaluation.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/trunk@2053 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/Main/Base/Project/Src/Project/MSBuildInternals.cs

@@ -196,8 +196,8 @@ namespace ICSharpCode.SharpDevelop.Project
 		{
 			const string propertyName = "MSBuildInternalsEvaluateConditionDummyPropertyName";
 			MSBuild.BuildPropertyGroup pGroup = project.AddNewPropertyGroup(true);
-			pGroup.Condition = condition;
+			pGroup.AddNewProperty(propertyName, "ConditionFalse");
-			pGroup.AddNewProperty(propertyName, "ConditionTrue");
+			pGroup.AddNewProperty(propertyName, "ConditionTrue").Condition = condition;
 			bool result = project.GetEvaluatedProperty(propertyName) == "ConditionTrue";
 			project.RemovePropertyGroup(pGroup);
 			return result;