From 72955221cbb017fbc207925e5357073f9369bf51 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Beat=20K=C3=BCng?= <beat-kueng@gmx.net>
Date: Mon, 19 Jun 2023 11:41:50 +0200
Subject: [PATCH] fix dataman: treat 0 as valid return for read & ensure to
 init buffer

This can happen e.g. when the item is cleared.
---
 src/modules/dataman/dataman.cpp | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/src/modules/dataman/dataman.cpp b/src/modules/dataman/dataman.cpp
index f4345cc685..eb25328a5b 100644
--- a/src/modules/dataman/dataman.cpp
+++ b/src/modules/dataman/dataman.cpp
@@ -430,6 +430,9 @@ _file_read(dm_item_t item, unsigned index, void *buf, size_t count)
 
 		/* Looks good, copy it to the caller's buffer */
 		memcpy(buf, buffer + DM_SECTOR_HDR_SIZE, buffer[0]);
+
+	} else {
+		memset(buf, 0, count);
 	}
 
 	/* Return the number of bytes of caller data read */
@@ -754,7 +757,7 @@ task_main(int argc, char *argv[])
 
 					perf_end(_dm_read_perf);
 
-					if (result > 0) {
+					if (result >= 0) {
 						response.status = dataman_response_s::STATUS_SUCCESS;
 
 					} else {