public void Issue604_RecoversFromFailedCommit()
{
db.Trace = true;
var initialCount = db.Table <TestObj> ().Count();
//
// Well this is an issue because there is an internal variable called _transactionDepth
// that tries to track if we are in an active transaction.
// The problem is, _transactionDepth is set to 0 and then commit is executed on the database.
// Well, the commit fails and "When COMMIT fails in this way, the transaction remains active and
// the COMMIT can be retried later after the reader has had a chance to clear"
//
var rollbacks = 0;
db.Tracer = m => {
if (m == "Executing: commit")
{
throw SQLiteException.New(SQLite3.Result.Busy, "Make commit fail");
}
if (m == "Executing: rollback")
{
rollbacks++;
}
};
db.BeginTransaction();
db.Insert(new TestObj());
try {
db.Commit();
Assert.Fail("Should have thrown");
}
catch (SQLiteException ex) when(ex.Result == SQLite3.Result.Busy)
{
db.Tracer = null;
}
Assert.False(db.IsInTransaction);
Assert.AreEqual(1, rollbacks);
//
// The catch statements in the RunInTransaction family of functions catch this and call rollback,
// but since _transactionDepth is 0, the transaction isn't actually rolled back.
//
// So the next time begin transaction is called on the same connection,
// sqlite-net attempts to begin a new transaction (because _transactionDepth is 0),
// which promptly fails because there is still an active transaction on the connection.
//
// Well now we are in big trouble because _transactionDepth got set to 1,
// and when begin transaction fails in this manner, the transaction isn't rolled back
// (which would have set _transactionDepth to 0)
//
db.BeginTransaction();
db.Insert(new TestObj());
db.Commit();
Assert.AreEqual(initialCount + 1, db.Table <TestObj> ().Count());
}
