[pgpool-committers: 3869] pgpool: Fix bugs regarding empty query response and deallocate.

[Tatsuo Ishii]

Fix bugs regarding empty query response and deallocate.

The bug was analyzed in pgpool-hackers: 2173
http://www.pgpool.net/pipermail/pgpool-hackers/2017-March/002173.html

Pgpool-II needs to treat empty query response exactly same as command
complete so implement it.

Also I found issue with parse_before_bind. If a client sends bind
message multiple times and thus parse_before_bind gets called multiple
times, a named statement could be duplicated which cause an error from
backend. So solution is before sending a parse message to primary,
close the named statement.

Branch
------
bug271

Details
-------
http://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=e50ec2f9104bd706e476987e294100194748a592

Modified Files
--------------
src/context/pool_query_context.c          | 37 +++++------------
src/include/context/pool_query_context.h  |  3 +-
src/include/protocol/pool_proto_modules.h |  7 +---
src/protocol/CommandComplete.c            | 38 +++++++++++++++---
src/protocol/pool_process_query.c         | 12 +++---
src/protocol/pool_proto_modules.c         | 67 ++++++++++++++++++++++++++-----
6 files changed, 110 insertions(+), 54 deletions(-)