From: Erwin Janssen <erwinjanssen@outlook.com>
Date: Sat, 19 Nov 2016 00:53:25 +0000 (+0100)
Subject: Fixed: 'dereference before null check' in stack.c
X-Git-Tag: 2.42.0~229^2~3
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=08da710165f71c5ec404d6e7232665927668131b;p=graphviz

Fixed: 'dereference before null check' in stack.c

The pointer `theStack` is dereferenced before the if statement that
checks whether `theStack` is null. This is fixed by placing the variable
declarations in the if statement.
---

diff --git a/lib/rbtree/stack.c b/lib/rbtree/stack.c
index b269b937a..1b93b9d99 100755
--- a/lib/rbtree/stack.c
+++ b/lib/rbtree/stack.c
@@ -69,10 +69,9 @@ DATA_TYPE StackPop(stk_stack * theStack) {
 }
 
 void StackDestroy(stk_stack * theStack,void DestFunc(void * a)) {
-  stk_stack_node * x=theStack->top;
-  stk_stack_node * y;
-
   if(theStack) {
+    stk_stack_node * x=theStack->top;
+    stk_stack_node * y;
     while(x) {
       y=x->next;
       DestFunc(x->info);