[KAFKA-15680] Partition-Count is not getting updated Correctly in the Incremental Co-operative Rebalancing(ICR) Mode of Rebalancing - ASF JIRA

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In ICR(Incremental Cooperative Rebalancing) mode, whenever a new worker, say Worker 3 joins, a new global assignment is computed by the leader, say Worker1, that results in the revocation of some tasks from each existing worker i.e Worker1 and Worker2.
Once the new member join is completed, ConsumerCoordinator.OnJoinComplete() method is called which primarily computes all the new partitions assigned and the partitions which are revoked and updates the subscription Object.
If it was the case of revocation which we check by checking the “partitonsRevoked” list, we call the method “invokePartitionRevoked()” which internally calls “updatePartitionCount()” which fetches partition from the assignment object which is yet not updated by the new assignment.
It is only just before calling the “invokePartitionsAssigned()” method that we update the assignment by invoking the following → subscriptions.assignFromSubscribed(assignedPartitions);

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GitHub Pull Request #14630