pg_receivexlog: spurious error message connecting to 9.3

Hi,

I was testing the compatibility of pg_receivexlog with the previous PostgreSQL versions and I've discovered that in 9.5 and 9.6, although being compatible with 9.3, it prints an ugly but harmless error message.

$ 9.5/bin/pg_receivexlog -D /tmp/testx -v -p 5493
*pg_receivexlog: could not identify system: got 1 rows and 3 fields, expected 1 rows and 4 or more fields*
*column number 3 is out of range 0..2*
pg_receivexlog: starting log streaming at 0/4000000 (timeline 1)

After the error, the streaming starts and continue without issue, as it was printed by the code that checks if the connection is not database specific, and this check is not needed on 9.3.

I've attached a little patch that removes the errors when connected to 9.3.

Regards,
Marco

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Marco Nenciarini - 2ndQuadrant Italy
PostgreSQL Training, Services and Support
marco(dot)nenciarini(at)2ndQuadrant(dot)it | www.2ndQuadrant.it