Consumer group ignores AutoCommit flag when it exits

[hipper]

Versions

Please specify real version numbers or git SHAs, not just "Latest" since that changes fairly regularly.

Sarama	Kafka	Go
1.27.2	2.7.0	1.14

Problem Description

When consumer's AutoCommit flag is disabled by configuration and you mark offset during the process with session.MarkMessage(msg, "") it doesn't commit the offset as expected. However when you terminate the consumer (or rebalancing is triggered) it commits the offset ignoring the AutoCommit flag.

This is likely related to this PR: #1699
This PR removes the check:

// flushToBroker is ignored if auto-commit offsets is disabled
func (om *offsetManager) flushToBroker() {
	if !om.conf.Consumer.Offsets.AutoCommit.Enable {
		return
	}
        ...

I test using Sarama 1.26.4 where that check is in place and it works as expected, but 1.27.2 commits the offset on Close() which is likely a bug.

[ghost]

Thank you for taking the time to raise this issue. However, it has not had any activity on it in the past 90 days and will be closed in 30 days if no updates occur.
Please check if the master branch has already resolved the issue since it was raised. If you believe the issue is still valid and you would like input from the maintainers then please comment to ask for it to be reviewed.

[dnwe]

Fixed by #1846