Fixed possible exceptions in Boo code-completion.

git-svn-id: svn://svn.sharpdevelop.net/sharpdevelop/branches/2.0@1403 1ccf3a8d-04fe-1044-b7c0-cef0b8235c61

src/AddIns/BackendBindings/Boo/BooBinding/Project/Src/CodeCompletion/InferredReturnType.cs

@@ -100,19 +100,27 @@ namespace Grunwald.BooBinding.CodeCompletion
 			public override void OnYieldStatement(YieldStatement node)
 			{
 				noReturnStatement = false;
-				IClass enumerable = ProjectContentRegistry.Mscorlib.GetClass("System.Collections.Generic.IEnumerable", 1);
+				
+				IProjectContent pc = context != null ? context.ProjectContent : ParserService.CurrentProjectContent;
+				IReturnType enumerable = new GetClassReturnType(pc, "System.Collections.Generic.IEnumerable", 1);
 				
 				// Prevent creating an infinite number of InferredReturnTypes in inferring cycles
 				parentReturnType.expression = new NullLiteralExpression();
-				IReturnType returnType = new BooResolver().GetTypeOfExpression(node.Expression, context);
-				returnType.GetUnderlyingClass(); // force to infer type
+				IReturnType returnType;
+				if (node.Expression == null)
+					returnType = ReflectionReturnType.Object;
+				else
+					returnType = new BooResolver().GetTypeOfExpression(node.Expression, context);
+				if (returnType != null) {
+					returnType.GetUnderlyingClass(); // force to infer type
+				}
 				if (parentReturnType.expression == null) {
 					// inferrence cycle with parentReturnType
 					returnType = new GetClassReturnType(context.ProjectContent, "?", 0);
 				}
 				parentReturnType.expression = null;
 				
-				result = new ConstructedReturnType(enumerable.DefaultReturnType, new IReturnType[] { returnType });
+				result = new ConstructedReturnType(enumerable, new IReturnType[] { returnType });
 			}
 			
 			public override void OnCallableBlockExpression(CallableBlockExpression node)

src/AddIns/BackendBindings/Boo/BooBinding/Project/Src/CodeCompletion/ResolveVisitor.cs

@@ -504,10 +504,12 @@ namespace Grunwald.BooBinding.CodeCompletion
 		{
 			ClearResult();
 			Visit(node.Target);
-			Slice slice = node.Indices[0];
-			if (slice.End != null) {
-				// Boo slice, returns a part of the source -> same type as source
-				return;
+			if (node.Indices.Count > 0) {
+				Slice slice = node.Indices[0];
+				if (slice.End != null) {
+					// Boo slice, returns a part of the source -> same type as source
+					return;
+				}
 			}
 			IReturnType rt = (resolveResult != null) ? resolveResult.ResolvedType : null;
 			if (rt == null) {