From 60641ca499136ccf64ad081b9e783dacf45082e9 Mon Sep 17 00:00:00 2001
From: Murilo Pereira <murilo.soares3@gmail.com>
Date: Sat, 12 Feb 2011 01:26:03 -0200
Subject: [PATCH] Avoid dereferencing NULL pointers.

---
 lib/card.c  |  4 +++-
 lib/deck.c  | 28 ++++++++++++++--------------
 lib/frame.c |  4 +++-
 lib/stack.c |  4 +++-
 4 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/lib/card.c b/lib/card.c
index f43d6ba..28073aa 100644
--- a/lib/card.c
+++ b/lib/card.c
@@ -26,7 +26,9 @@ void initialize_card(struct card *card) {
 }
 
 void delete_card(struct card *card) {
-  delete_frame(card->frame);
+  if (card) {
+    delete_frame(card->frame);
+  }
   free(card);
 
   return;
diff --git a/lib/deck.c b/lib/deck.c
index ac8305a..8ad7697 100644
--- a/lib/deck.c
+++ b/lib/deck.c
@@ -51,22 +51,22 @@ void initialize_deck(struct deck *deck) {
 }
 
 void delete_deck(struct deck *deck) {
-  delete_stack(deck->stock);
-  delete_stack(deck->waste_pile);
+  if (deck) {
+    delete_stack(deck->waste_pile);
 
-  delete_stack(deck->foundation_0);
-  delete_stack(deck->foundation_1);
-  delete_stack(deck->foundation_2);
-  delete_stack(deck->foundation_3);
-
-  delete_stack(deck->maneuvre_0);
-  delete_stack(deck->maneuvre_1);
-  delete_stack(deck->maneuvre_2);
-  delete_stack(deck->maneuvre_3);
-  delete_stack(deck->maneuvre_4);
-  delete_stack(deck->maneuvre_5);
-  delete_stack(deck->maneuvre_6);
+    delete_stack(deck->foundation_0);
+    delete_stack(deck->foundation_1);
+    delete_stack(deck->foundation_2);
+    delete_stack(deck->foundation_3);
 
+    delete_stack(deck->maneuvre_0);
+    delete_stack(deck->maneuvre_1);
+    delete_stack(deck->maneuvre_2);
+    delete_stack(deck->maneuvre_3);
+    delete_stack(deck->maneuvre_4);
+    delete_stack(deck->maneuvre_5);
+    delete_stack(deck->maneuvre_6);
+  }
   free(deck);
 
   return;
diff --git a/lib/frame.c b/lib/frame.c
index 427576d..8eb7c60 100644
--- a/lib/frame.c
+++ b/lib/frame.c
@@ -23,7 +23,9 @@ void initialize_frame(struct frame *frame) {
 }
 
 void delete_frame(struct frame *frame) {
-  delwin(frame->shape);
+  if (frame) {
+    delwin(frame->shape);
+  }
   free(frame);
 
   return;
diff --git a/lib/stack.c b/lib/stack.c
index fd89986..f90ebfa 100644
--- a/lib/stack.c
+++ b/lib/stack.c
@@ -29,7 +29,9 @@ void initialize_stack(struct stack *stack) {
 }
 
 void delete_stack(struct stack *stack) {
-  delete_card(stack->card);
+  if (stack) {
+    delete_card(stack->card);
+  }
   free(stack);
 
   return;