fixes

circbuf_deque/circbuf.c

@@ -139,7 +139,7 @@ bool cbuf_peek(const CircBuf *cb, void *dest)
 
 void * cbuf_ptr(const CircBuf *cb)
 {
-    if (cb == NULL || dest == NULL || cb->num_used == 0) {
+    if (cb == NULL || cb->num_used == 0) {
         return NULL;
     }
 
@@ -163,7 +163,7 @@ bool cbuf_nth(const CircBuf *cb, circbuf_size_t num, void *dest)
 
 void *cbuf_ptr_nth(const CircBuf *cb, circbuf_size_t num)
 {
-    if (cb == NULL || dest == NULL || num > cb->num_used) {
+    if (cb == NULL || num > cb->num_used) {
         return NULL;
     }
 
@@ -231,7 +231,7 @@ bool cbuf_peek_back(const CircBuf *cb, void *dest)
 
 void* cbuf_ptr_back(const CircBuf *cb)
 {
-    if (cb == NULL || dest == NULL || cb->num_used == 0) {
+    if (cb == NULL || cb->num_used == 0) {
         return NULL;
     }
 

circbuf_deque/circbuf.h

@@ -20,6 +20,7 @@
 // Enable to zero a freed slots after pop, useful for debugging
 #define CIRCBUF_ZERO_FREE_SLOTS
 
+// size_t can be replaced by a more suitable type for circbuf, e.g. uint8_t for tiny buffers
 typedef uint32_t circbuf_size_t;
 
 /** Instance structure - public to allow static allocation, but consider the structure internal matter */