From 7c30e006b6150ae7cde055bf7a8fa072e30276a2 Mon Sep 17 00:00:00 2001
From: Murilo Soares Pereira <murilo.soares3@gmail.com>
Date: Fri, 9 Apr 2010 01:23:10 -0300
Subject: [PATCH] Fixed the function that checks if a given stack is empty.

---
 lib/stack.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/stack.c b/lib/stack.c
index e712ac9..fb49e49 100644
--- a/lib/stack.c
+++ b/lib/stack.c
@@ -25,7 +25,7 @@ void delete_stack(struct stack *stack) {
 }
 
 bool empty(struct stack *stack) {
-  return(stack->card == NULL);
+  return(stack->card->value == NO_VALUE);
 }
 
 int length(struct stack *stack) {