From 72231e07cdb990c1cd382b4a74f60a1bec8674f0 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jo=C3=ABl=20G=C3=A4hwiler?= <joel.gaehwiler@gmail.com>
Date: Wed, 25 Oct 2017 00:38:11 +0300
Subject: [PATCH] fixed bit helpers

---
 src/helpers.c | 8 ++++----
 src/helpers.h | 4 ++--
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/src/helpers.c b/src/helpers.c
index 0a51ac9..8b9d37e 100644
--- a/src/helpers.c
+++ b/src/helpers.c
@@ -2,12 +2,12 @@
 
 #include "helpers.h"
 
-uint8_t lwmqtt_read_bits(uint8_t byte, uint8_t pos, uint8_t num) {
-  return (byte & (uint8_t)((~((~0) << num)) << pos)) >> pos;
+uint8_t lwmqtt_read_bits(uint8_t byte, int pos, int num) {
+  return (byte & (uint8_t)((~(0xFF << num)) << pos)) >> pos;
 }
 
-void lwmqtt_write_bits(uint8_t *byte, uint8_t value, uint8_t pos, uint8_t num) {
-  *byte = (*byte & ~(uint8_t)((~((~0) << num)) << pos)) | (value << pos);
+void lwmqtt_write_bits(uint8_t *byte, uint8_t value, int pos, int num) {
+  *byte = (*byte & ~(uint8_t)((~(0xFF << num)) << pos)) | (value << pos);
 }
 
 lwmqtt_err_t lwmqtt_read_data(uint8_t **buf, const uint8_t *buf_end, uint8_t **data, size_t len) {
diff --git a/src/helpers.h b/src/helpers.h
index a008e36..4a62e66 100644
--- a/src/helpers.h
+++ b/src/helpers.h
@@ -11,7 +11,7 @@
  * @param num - The number of bits to read.
  * @return The read bits as a byte.
  */
-uint8_t lwmqtt_read_bits(uint8_t byte, uint8_t pos, uint8_t num);
+uint8_t lwmqtt_read_bits(uint8_t byte, int pos, int num);
 
 /**
  * Write bits to a byte.
@@ -21,7 +21,7 @@ uint8_t lwmqtt_read_bits(uint8_t byte, uint8_t pos, uint8_t num);
  * @param pos - The position of the first bit.
  * @param num - The number of bits to write.
  */
-void lwmqtt_write_bits(uint8_t *byte, uint8_t value, uint8_t pos, uint8_t num);
+void lwmqtt_write_bits(uint8_t *byte, uint8_t value, int pos, int num);
 
 /**
  * Reads arbitrary data from the specified buffer. The pointer is incremented by bytes read.