[xBuild] Suport >= in string conditions

e.g: '$(MSBuildAssemblyVersion)' == '' and ('$(VisualStudioVersion)' != '' and '$(VisualStudioVersion)' >= '12.0'), used in the .targets files shipped with VS2013

1 files changed, 5 insertions, 0 deletions

diff --git a/mcs/class/Microsoft.Build.Engine/Microsoft.Build.BuildEngine/ConditionFactorExpresion.cs b/mcs/class/Microsoft.Build.Engine/Microsoft.Build.BuildEngine/ConditionFactorExpresion.cs
index 709fedf1ce8..bf619219025 100644
--- a/mcs/class/Microsoft.Build.Engine/Microsoft.Build.BuildEngine/ConditionFactorExpresion.cs
+++ b/mcs/class/Microsoft.Build.Engine/Microsoft.Build.BuildEngine/ConditionFactorExpresion.cs
@@ -109,6 +109,11 @@ namespace Microsoft.Build.BuildEngine {
 		{
 			if (token.Type == TokenType.Number)
 				return true;
+			else if (token.Type == TokenType.String) {
+				var text = StringEvaluate (context);
+				Single number;
+				return Single.TryParse (text, out number);
+			}
 			else
 				return false;
 		}