Bug in in-transaction-p?

In a similar vein to Alexey's bug in database-start-transaction,
shouldn't 
in-transaction-p have:

  (and database (transaction database) (> (transaction-level database)
  0)))

rather than:

  (and database (transaction database) (= (transaction-level database)
  1)))

which only returns true in the outermost transaction?

- Dominic