pgsql: Cancel running query if it is detected that the connection to th

Cancel running query if it is detected that the connection to the client is
lost. The only way we detect that at the moment is when write() fails when
we try to write to the socket.

Florian Pflug with small changes by me, reviewed by Greg Jaskiewicz.

Branch
------
master

Details
-------
http://git.postgresql.org/pg/commitdiff/5d8a894e3095b2f602e901c19689f3176bf20543

Modified Files
--------------
src/backend/libpq/pqcomm.c       |    6 +++++-
src/backend/tcop/postgres.c      |   12 ++++++++++++
src/backend/utils/init/globals.c |    1 +
src/include/miscadmin.h          |    7 +++++++
4 files changed, 25 insertions(+), 1 deletions(-)