pgsql: Fix pg_recvlogical not to fsync output when it's a tty or pipe.

Fix pg_recvlogical not to fsync output when it's a tty or pipe.

The previous coding tried to handle possible failures when fsyncing a
tty or pipe fd by accepting EINVAL - but apparently some
platforms (windows, OSX) don't reliably return that. So instead check
whether the output fd refers to a pipe or a tty when opening it.

Reported-By: Olivier Gosseaume, Marko Tiikkaja
Discussion: 559AF98B(dot)3050901(at)joh(dot)to

Backpatch to 9.4, where pg_recvlogical was added.

Branch
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REL9_4_STABLE

Details
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http://git.postgresql.org/pg/commitdiff/1790b35baf52fff7f670f7cc1159a1b40b36e701

Modified Files
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src/bin/pg_basebackup/pg_recvlogical.c | 17 +++++++++++++++--
1 file changed, 15 insertions(+), 2 deletions(-)