Carefull with transaction/1 and meta information

Help!
1

Now I observed that transaction/1 does not rollback
predicate meta information. I get the following, with
snapshot/1 which does a rollback at end:

?- current_predicate(foo/1).
false.
?- snapshot(assertz(foo(bar))).
true.
?- current_predicate(foo/1).
true.

And with transaction/1 calling abort/0 to force a rollback:

?- current_predicate(foo/1).
false.

?- transaction((assertz(foo(bar)), abort)).
% Execution Aborted
?- current_predicate(foo/1).
true.

My expectation was rather that the last query gives false, i.e. that
the rollback also restores predicate existence, the example is also
only a monotonic change to meta information.

Edit 14.07.2022:
Looks like I can simulate SWI-Prolog snapshot/1 in Dogelog player
since this weekend.

snapshot(G) :-
   current_prolog_flag(stage, S),
   T is S+1,
   set_prolog_flag(stage, T),
   G,
   sy_clear_stage, /* rollback */
   set_prolog_flag(stage, S).

And it works differently, since I added meta information rollback.

?- current_predicate(foo/1).
fail.
?- snapshot(assertz(foo(bar))).
true.
?- current_predicate(foo/1).
fail. /* gives false in SWI-Prolog */

I do not have a commit statement yet, so I guess I cannot yet
simulate SWI-Prolog transaction/1.