message: add (failing) test that checks that we clear query stack
diff: @@ -64,3 +64,17 @@ fn storages_are_unwind_safe() {
  fn check_unwind_safe<T: std::panic::UnwindSafe>() {}
  check_unwind_safe::<&DatabaseStruct>();
  }
  +
  +#[test]
  +fn panics_clear_query_stack() {
  + let db = DatabaseStruct::default();
  +
  + // Invoke `db.panic_if_not_one() without having set `db.input`. `db.input`
  + // will default to 0 and we should catch the panic.
  + let result = panic::catch_unwind(AssertUnwindSafe(|| db.panic_safely()));
  + assert!(result.is_err());
  +
  + // The database has been poisoned and any attempt to increment the
  + // revision should panic.
  + assert_eq!(db.salsa_runtime().active_query(), None);
  +}
  