From 9a61f79a72e67388eb2b2db3ff4db4a7f60be556 Mon Sep 17 00:00:00 2001
From: skarg <skarg@1e814d3a-8a88-4260-be86-c0dc25669c1e>
Date: Tue, 16 Sep 2008 12:59:06 +0000
Subject: [PATCH] Added NULL pointer checking to ring buffer library.

---
 bacnet-stack/src/ringbuf.c | 21 +++++++++++++--------
 1 file changed, 13 insertions(+), 8 deletions(-)

diff --git a/bacnet-stack/src/ringbuf.c b/bacnet-stack/src/ringbuf.c
index 3a9568aa..1d28d90a 100644
--- a/bacnet-stack/src/ringbuf.c
+++ b/bacnet-stack/src/ringbuf.c
@@ -49,7 +49,7 @@
 bool Ringbuf_Empty(
     RING_BUFFER const *b)
 {
-    return (b->count == 0);
+    return (b ? b->count == 0 : true);
 }
 
 /****************************************************************************
@@ -61,7 +61,10 @@ bool Ringbuf_Empty(
 char *Ringbuf_Get_Front(
     RING_BUFFER const *b)
 {
-    return (b->count ? &(b->data[b->head * b->element_size]) : NULL);
+    if (b) {
+        return (b->count ? &(b->data[b->head * b->element_size]) : NULL);
+    }
+    return NULL;
 }
 
 /****************************************************************************
@@ -75,7 +78,7 @@ char *Ringbuf_Pop_Front(
 {
     char *data = NULL;  /* return value */
 
-    if (b->count) {
+    if (b && b->count) {
         data = &(b->data[b->head * b->element_size]);
         b->head++;
         if (b->head >= b->element_count)
@@ -131,11 +134,13 @@ void Ringbuf_Init(
     unsigned element_size,      /* size of one element in the data block */
     unsigned element_count)
 {       /* number of elements in the data block */
-    b->head = 0;
-    b->count = 0;
-    b->data = data;
-    b->element_size = element_size;
-    b->element_count = element_count;
+    if (b) {
+        b->head = 0;
+        b->count = 0;
+        b->data = data;
+        b->element_size = element_size;
+        b->element_count = element_count;
+    }
 
     return;
 }