luci-lib-jsonc: Ignore non-string-or-number keys in tables

Previously, the following caused a segmentation fault:

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

This was caused by lua_tostring() returning NULL for anything but
strings and numbers, letting json_object_object_add crash.

This patch makes jsonc ignore all keys which have no string
representation altogether.

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

diff --git a/libs/luci-lib-jsonc/src/jsonc.c b/libs/luci-lib-jsonc/src/jsonc.c
index 49cb21f5bcb2817792d0eef8dc5cd567bc6d86bc..827fde8843082e956b0c89b5855feeabd790e880 100644 (file)
--- a/libs/luci-lib-jsonc/src/jsonc.c
+++ b/libs/luci-lib-jsonc/src/jsonc.c
@@ -286,8 +286,9 @@ static struct json_object * _lua_to_json(lua_State *L, int index)
                        lua_pushvalue(L, -2);
                        key = lua_tostring(L, -1);
 
-                       json_object_object_add(obj, key,
-                                                                  _lua_to_json(L, lua_gettop(L) - 1));
+                       if (key)
+                               json_object_object_add(obj, key,
+                                                      _lua_to_json(L, lua_gettop(L) - 1));
 
                        lua_pop(L, 2);
                }