Fully resolve extension method argument. Fixes #11213

2 files changed, 24 insertions, 1 deletions

diff --git a/mcs/errors/cs0154-5.cs b/mcs/errors/cs0154-5.cs
new file mode 100644
index 00000000000..21f55ceae5a
--- /dev/null
+++ b/mcs/errors/cs0154-5.cs
@@ -0,0 +1,19 @@
+// CS0154: The property or indexer `BugReport.MyProperty' cannot be used in this context because it lacks the `get' accessor
+// Line: 16
+
+static class BugReport
+{
+	static float MyProperty {
+		set { }
+	}
+
+	static void MyExtension (this float val)
+	{
+	}
+
+	public static void Main ()
+	{
+		MyProperty.MyExtension ();
+	}
+}
+
diff --git a/mcs/mcs/ecore.cs b/mcs/mcs/ecore.cs
index ee025092c44..e8bd8554dcd 100644
--- a/mcs/mcs/ecore.cs
+++ b/mcs/mcs/ecore.cs
@@ -3244,7 +3244,7 @@ namespace Mono.CSharp {
 	class ExtensionMethodGroupExpr : MethodGroupExpr, OverloadResolver.IErrorHandler
 	{
 		ExtensionMethodCandidates candidates;
-		public readonly Expression ExtensionExpression;
+		public Expression ExtensionExpression;
 
 		public ExtensionMethodGroupExpr (ExtensionMethodCandidates candidates, Expression extensionExpr, Location loc)
 			: base (candidates.Methods.Cast<MemberSpec>().ToList (), extensionExpr.Type, loc)
@@ -3288,6 +3288,10 @@ namespace Mono.CSharp {
 			if (arguments == null)
 				arguments = new Arguments (1);
 
+			ExtensionExpression = ExtensionExpression.Resolve (ec);
+			if (ExtensionExpression == null)
+				return null;
+
 			arguments.Insert (0, new Argument (ExtensionExpression, Argument.AType.ExtensionType));
 			var res = base.OverloadResolve (ec, ref arguments, ehandler ?? this, restr);