psql: Fix invalid memory access
psql: Fix invalid memory access

Due to an apparent thinko, when printing a table in expanded mode
(\x), space would be allocated for 1 slot plus 1 byte per line,
instead of 1 slot per line plus 1 slot for the NULL terminator.  When
the line count is small, reading or writing the terminator would
therefore access memory beyond what was allocated.

tpostgres-projects/tPostgres,50wu/gpdb,arcivanov/postgres-xl,oberstet/postgres-xl,Postgres-XL/Postgres-XL,lisakowen/gpdb,pavanvd/postgres-xl,greenplum-db/gpdb,zeroae/postgres-xl,ashwinstar/gpdb,oberstet/postgres-xl,greenplum-db/gpdb,ashwinstar/gpdb,xinzweb/gpdb,snaga/postgres-xl,xinzweb/gpdb,snaga/postgres-xl,techdragon/Postgres-XL,50wu/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,postmind-net/postgres-xl,adam8157/gpdb,xinzweb/gpdb,yazun/postgres-xl,arcivanov/postgres-xl,postmind-net/postgres-xl,adam8157/gpdb,50wu/gpdb,50wu/gpdb,tpostgres-projects/tPostgres,Postgres-XL/Postgres-XL,yazun/postgres-xl,adam8157/gpdb,greenplum-db/gpdb,arcivanov/postgres-xl,50wu/gpdb,lisakowen/gpdb,adam8157/gpdb,kmjungersen/PostgresXL,adam8157/gpdb,Postgres-XL/Postgres-XL,adam8157/gpdb,ashwinstar/gpdb,jmcatamney/gpdb,ovr/postgres-xl,tpostgres-projects/tPostgres,Postgres-XL/Postgres-XL,pavanvd/postgres-xl,snaga/postgres-xl,jmcatamney/gpdb,xinzweb/gpdb,yazun/postgres-xl,postmind-net/postgres-xl,pavanvd/postgres-xl,jmcatamney/gpdb,ovr/postgres-xl,lisakowen/gpdb,arcivanov/postgres-xl,jmcatamney/gpdb,oberstet/postgres-xl,arcivanov/postgres-xl,xinzweb/gpdb,50wu/gpdb,jmcatamney/gpdb,ovr/postgres-xl,greenplum-db/gpdb,techdragon/Postgres-XL,jmcatamney/gpdb,snaga/postgres-xl,tpostgres-projects/tPostgres,lisakowen/gpdb,zeroae/postgres-xl,yazun/postgres-xl,xinzweb/gpdb,tpostgres-projects/tPostgres,greenplum-db/gpdb,kmjungersen/PostgresXL,lisakowen/gpdb,jmcatamney/gpdb,ashwinstar/gpdb,adam8157/gpdb,techdragon/Postgres-XL,ashwinstar/gpdb,yazun/postgres-xl,zeroae/postgres-xl,greenplum-db/gpdb,xinzweb/gpdb,ovr/postgres-xl,ashwinstar/gpdb,techdragon/Postgres-XL,kmjungersen/PostgresXL,kmjungersen/PostgresXL,snaga/postgres-xl,greenplum-db/gpdb,arcivanov/postgres-xl,greenplum-db/gpdb,zeroae/postgres-xl,zeroae/postgres-xl,ovr/postgres-xl,kmjungersen/PostgresXL,oberstet/postgres-xl,lisakowen/gpdb,Postgres-XL/Postgres-XL,50wu/gpdb,oberstet/postgres-xl,techdragon/Postgres-XL,postmind-net/postgres-xl,lisakowen/gpdb,pavanvd/postgres-xl,adam8157/gpdb,pavanvd/postgres-xl,ashwinstar/gpdb,xinzweb/gpdb,50wu/gpdb,postmind-net/postgres-xl,lisakowen/gpdb