From: Antonio Ospite <ao2@ao2.it>
Date: Wed, 14 Sep 2016 11:32:02 +0000 (+0200)
Subject: visomat-data-downloader: document why code is 4 bytes in decode_datetime()
X-Git-Url: https://git.ao2.it/visomat-utils.git/commitdiff_plain/97621eb0841882c78fd400f3c6ee3600fc56613e

visomat-data-downloader: document why code is 4 bytes in decode_datetime()
---

diff --git a/src/visomat-data-downloader.c b/src/visomat-data-downloader.c
index a3282ba..1cbe6f5 100644
--- a/src/visomat-data-downloader.c
+++ b/src/visomat-data-downloader.c
@@ -234,7 +234,7 @@ static int decode_eeprom(uint8_t *buffer,
 static int decode_datetime(uint8_t *buffer, unsigned int len)
 {
 	int ret;
-	uint8_t code[4] = { 0 };
+	uint8_t code[4] = { 0 }; /* the initial STX + 3 bytes command code */
 	struct datetime d;
 	uint8_t *pbuffer = buffer;
 
@@ -245,7 +245,7 @@ static int decode_datetime(uint8_t *buffer, unsigned int len)
 	code[1] = buffer[2];
 	code[2] = buffer[3];
 
-	ret = extract_datetime(pbuffer + 4, &d);
+	ret = extract_datetime(pbuffer + sizeof(code), &d);
 	if (ret < 0)
 		return ret;