luci-lib-jsonc: allow encoding empty lists

To be consistent with the behavior of luci-lib-json, an empty Lua table
should be encoded to an empty JSON list, not an empty JSON object.

To still allow encoding empty JSON objects, the usage of anything other
than a number or a string as a key (for example an empty table or a
function) can be used to force encoding as an object:

    json.stringify({})                  -- "[]"
    json.stringify({[{}] = true})       -- "{}"

Signed-off-by: Jan-Philipp Litza <janphilipp@litza.de>

1 files changed, 2 insertions, 2 deletions

diff --git a/libs/luci-lib-jsonc/src/jsonc.c b/libs/luci-lib-jsonc/src/jsonc.c
index 827fde884..971fb122f 100644
--- a/libs/luci-lib-jsonc/src/jsonc.c
+++ b/libs/luci-lib-jsonc/src/jsonc.c
@@ -222,7 +222,7 @@ static int _lua_test_array(lua_State *L, int index)
 
 out:
 		lua_pop(L, 2);
-		return 0;
+		return -1;
 	}
 
 	/* check for holes */
@@ -254,7 +254,7 @@ static struct json_object * _lua_to_json(lua_State *L, int index)
 	case LUA_TTABLE:
 		max = _lua_test_array(L, index);
 
-		if (max > 0)
+		if (max >= 0)
 		{
 			obj = json_object_new_array();