Issue observed in cascade standby setup and analysis for same

Below mentioned issue might be current behavior of PostgreSQL, but I am not able to find that in documentation so I have done brief analysis as well.

Issue: cascade standby server raise errors as “FATAL:  the database system is starting up” when trying to connect a client. Cascaded standby server is started on database which is received from Standby node using pg_basebackup tool.

Steps to reproduce:

M host is primary, S host is standby and CS host is cascaded standby.

1.        Set up postgresql-9.2beta2 on  all hosts.
2.        Execute command initdb on host M to create fresh database.
3.        Modify the configure file postgresql.conf on host M like this：
           listen_addresses = 'M'
           port = 15210
           wal_level = hot_standby  
           max_wal_senders = 4
           hot_standby = on
4.        modify the configure file pg_hba.conf on host M  like this：
           host     replication     repl             M/24            md5
5.        Start the server on host M as primary.
6.        Connect one client to primary server and create a user ‘repl’
                   create user repl superuser password '123';
7.        Use the command pg_basebackup on the host S to retrieve database of primary host
                    pg_basebackup  -D /opt/t38917/data -F p -x fetch -c fast -l repl_backup -P -v -h M -p 15210 -U repl –W
8.        Copy one recovery.conf.sample from share folder of package to database folder of the host S. Then rename this file to recovery.conf
9.        Modify the file recovery.conf on host S as below:
             standby_mode = on
             primary_conninfo = 'host=M port=15210 user=repl password=123'
10.        Modify the file postgresql.conf on host S as follow:
             listen_addresses = 'S'
11.        Start the server on host S as standby server.
12.        Use the command pg_basebackup on the host CS to retrieve database of standby host
             pg_basebackup  -D /opt/t38917/data -F p -x fetch -c fast -l repl_backup -P -v -h M -p 15210 -U repl –W
13.        Modify the file recovery.conf on host CS as below:
                  standby_mode = on
                  primary_conninfo = 'host=S port=15210 user=repl password=123'
14.        Modify the file postgresql.conf on host S as follow:
                  listen_addresses = 'CS'
15.        Start the server on host CS as Cascaded standby server node.
16.        Try to connect a client to host CS but it gives error as:
                        FATAL:  the database system is starting up

Observation based on code analysis:
In the above scenario it is observed that Start-up process has read all data (in our defect scenario minRecoveryPoint is 5016220) till the position 5016220 and then it goes and check for recovery consistency by following condition in function CheckRecoveryConsistency:
        if (!reachedConsistency &&
                XLByteLE(minRecoveryPoint, EndRecPtr) &&
                XLogRecPtrIsInvalid(ControlFile->backupStartPoint))

At this point first two conditions are true but last condition is not true because still redo has not been applied and hence backupStartPoint has not been reset. So it does not signal postmaster regarding consistent stage. After this it goes and applies the redo and then reset backupStartPoint and then it goes to read next set of record. Since all records have been already read, so it starts waiting for the new record from the Standby node. But since there is no new record from Standby node coming so it keeps waiting for that and it does not get chance to recheck the recovery consistent level. And hence client connection does not get allowed.

Suggestions?

With Regards,

Amit Kapila.