[ndctl PATCH] util/json: Use json_object_get_uint64() with uint64 support

[Justin Ernst <justin.ernst@hpe.com>]

If HAVE_JSON_U64=1, utils/json.c:display_hex() can call json_object_get_int64()
on a struct json_object created with json_object_new_uint64(). In the context of
'ndctl list --regions --human', this results in a static value of 0x7fffffffffffffff
being displayed for iset_id, as seen in #217.

Correct hex values are observed with the use of json_object_get_uint64(). To support
builds against older json-c, use a new static inline function util_json_get_u64() to
fallback to json_object_get_int64() if HAVE_JSON_U64=0.

Link: #217
Fixes: 691cd249 ("json: Add support for json_object_new_uint64()")
Signed-off-by: Justin Ernst <justin.ernst@hpe.com>
---
 util/json.c | 2 +-
 util/json.h | 8 ++++++++
 2 files changed, 9 insertions(+), 1 deletion(-)

diff --git a/util/json.c b/util/json.c
index 1d5c6bc..ba9daa3 100644
--- a/util/json.c
+++ b/util/json.c
@@ -75,7 +75,7 @@ static int display_size(struct json_object *jobj, struct printbuf *pbuf,
 static int display_hex(struct json_object *jobj, struct printbuf *pbuf,
 		int level, int flags)
 {
-	unsigned long long val = json_object_get_int64(jobj);
+	unsigned long long val = util_json_get_u64(jobj);
 	static char buf[32];
 
 	snprintf(buf, sizeof(buf), "\"%#llx\"", val);
diff --git a/util/json.h b/util/json.h
index ea370df..a8d0283 100644
--- a/util/json.h
+++ b/util/json.h
@@ -34,10 +34,18 @@ static inline struct json_object *util_json_new_u64(unsigned long long val)
 {
 	return json_object_new_uint64(val);
 }
+static inline unsigned long long util_json_get_u64(struct json_object *jobj)
+{
+	return json_object_get_uint64(jobj);
+}
 #else /* fallback to signed */
 static inline struct json_object *util_json_new_u64(unsigned long long val)
 {
 	return json_object_new_int64(val);
 }
+static inline unsigned long long util_json_get_u64(struct json_object *jobj)
+{
+	return json_object_get_int64(jobj);
+}
 #endif /* HAVE_JSON_U64 */
 #endif /* __UTIL_JSON_H__ */
-- 
2.26.2