From 02fb3867e16c07c0761e809cf2bab20cb8a2555e Mon Sep 17 00:00:00 2001
From: Deukhoofd <Deukhoofd@gmail.com>
Date: Sun, 17 Feb 2019 17:54:14 +0100
Subject: [PATCH] Throw error if for some reason the execution of a statement
 in a coroutine returns null

---
 Upsilon/Binder/BoundStatements/BoundBlockStatement.cs | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/Upsilon/Binder/BoundStatements/BoundBlockStatement.cs b/Upsilon/Binder/BoundStatements/BoundBlockStatement.cs
index 9b439da..d7a7f9b 100644
--- a/Upsilon/Binder/BoundStatements/BoundBlockStatement.cs
+++ b/Upsilon/Binder/BoundStatements/BoundBlockStatement.cs
@@ -39,6 +39,11 @@ namespace Upsilon.Binder
             foreach (var statement in Statements)
             {
                 var coroutine = statement.EvaluateCoroutine(scope, diagnostics, state);
+                if (coroutine == null)
+                {
+                    diagnostics.LogError("Can't evaluate a statement, it returned nil.", statement.Span);
+                    continue;
+                }
                 while (coroutine.MoveNext())
                 {
                     yield return coroutine.Current;