fix(ft): handle wider class of jiffy decode errors

With malformed cursors in the File listing API.

Fixes EMQX-9965

apps/emqx_ft/src/emqx_ft_storage_exporter_fs.erl

@@ -422,7 +422,7 @@ decode_cursor(Cursor) ->
         true = is_list(Name),
         {Node, #{transfer => {ClientId, FileId}, name => Name}}
     catch
-        error:{_, invalid_json} ->
+        error:{Loc, JsonError} when is_integer(Loc), is_atom(JsonError) ->
             error({badarg, cursor});
         error:{badmatch, _} ->
             error({badarg, cursor});

apps/emqx_ft/test/emqx_ft_api_SUITE.erl

@@ -216,6 +216,16 @@ t_list_files_paging(Config) ->
         request_json(get, uri(["file_transfer", "files"]) ++ query(#{limit => 0}))
     ),
 
+    ?assertMatch(
+        {ok, 400, #{<<"code">> := <<"BAD_REQUEST">>}},
+        request_json(get, uri(["file_transfer", "files"]) ++ query(#{following => <<>>}))
+    ),
+
+    ?assertMatch(
+        {ok, 400, #{<<"code">> := <<"BAD_REQUEST">>}},
+        request_json(get, uri(["file_transfer", "files"]) ++ query(#{following => <<"{\"\":}">>}))
+    ),
+
     ?assertMatch(
         {ok, 400, #{<<"code">> := <<"BAD_REQUEST">>}},
         request_json(