From 30b28b896439cf34499adacbae76f9fdf785d72e Mon Sep 17 00:00:00 2001
From: Jean Privat <jean@pryen.org>
Date: Sun, 12 Apr 2015 00:12:50 +0700
Subject: [PATCH] lib/ai/backtrack: add a missing assert

or else the possible null will loop and cause errors.

Signed-off-by: Jean Privat <jean@pryen.org>
---
 lib/ai/backtrack.nit |    1 +
 1 file changed, 1 insertion(+)

diff --git a/lib/ai/backtrack.nit b/lib/ai/backtrack.nit
index 550df10..ddc68ef 100644
--- a/lib/ai/backtrack.nit
+++ b/lib/ai/backtrack.nit
@@ -209,6 +209,7 @@ class BacktrackSolver[S: Object, A]
 
 				problem.backtrack(state, a)
 				node = node.parent
+				assert node != null
 				continue
 			end
 
-- 
1.7.9.5