[5.2][Database][Question] Commit method can cause negative transactionLevel

[marella]

Similar to #6360 but issue is because of commit method.
Calling commit method first will make transactionLevel go below 0.

DB::commit();
echo DB::transactionLevel(); // -1

Now calling DB::transaction() will not beginTransaction as transactionLevel is 0 but all changes are updated in database and rollBack is not possible.

DB::transaction(function() {
    echo DB::transactionLevel(); // 0
    DB::delete('DELETE FROM table_name');
    throw new Exception('foo'); // no rollBack happens
});

Shouldn't the commit method have a check on transactions like rollBack method?

--$this->transactions; // instead of this
$this->transactions = max(0, $this->transactions - 1); // use this

Or throw exception when trying to commit when there is no transaction?

if ($this->transactions === 0) {
    throw new RuntimeException('There is no active transaction');
}

[GrahamCampbell]

$this->transactions = max(0, $this->transactions - 1); // use this

No, that's just a hack that's not actually fixing the real issue.

[marella]

Wouldn't it be better to throw an exception when commit and rollBack methods are called with 0 transactionLevel?