[pgpool-committers: 1690] pgpool: Fix a segmentation fault in parallel mode with system_db_hostna

[Yugo Nagata]

Fix a segmentation fault in parallel mode with system_db_hostname is empty

When system_db_hostname is empty, unix domain socket should be used.
However, the directory containing the socket file was't specified in this
case, and the initialization of system DB connection failed. This caused
segmentation fault, when processing a query to system db.

Branch
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V3_0_STABLE

Details
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http://git.postgresql.org/gitweb?p=pgpool2.git;a=commitdiff;h=32115a33fcec2e4f83460359b4dc18122463ed15

Modified Files
--------------
doc/pgpool-en.html |    7 +-
doc/pgpool-ja.html |    8 +-
pool_config.c      | 1438 +++++++++++++++++++++++-----------------------------
pool_config.l      |   15 +-
4 files changed, 654 insertions(+), 814 deletions(-)