Make saveHistory work properly on OS X when HISTFILE is set to /dev/null. Per discussion with Martin Atukunda.
Make saveHistory work properly on OS X when HISTFILE is set to /dev/null.
Per discussion with Martin Atukunda.

lisakowen/gpdb,Postgres-XL/Postgres-XL,janebeckman/gpdb,edespino/gpdb,xinzweb/gpdb,jmcatamney/gpdb,xinzweb/gpdb,0x0FFF/gpdb,arcivanov/postgres-xl,Chibin/gpdb,foyzur/gpdb,snaga/postgres-xl,50wu/gpdb,atris/gpdb,arcivanov/postgres-xl,ovr/postgres-xl,CraigHarris/gpdb,yuanzhao/gpdb,randomtask1155/gpdb,tangp3/gpdb,lisakowen/gpdb,arcivanov/postgres-xl,arcivanov/postgres-xl,lpetrov-pivotal/gpdb,zaksoup/gpdb,zaksoup/gpdb,janebeckman/gpdb,ashwinstar/gpdb,xinzweb/gpdb,Chibin/gpdb,ahachete/gpdb,lintzc/gpdb,janebeckman/gpdb,ahachete/gpdb,lisakowen/gpdb,royc1/gpdb,chrishajas/gpdb,Chibin/gpdb,zeroae/postgres-xl,tangp3/gpdb,tangp3/gpdb,postmind-net/postgres-xl,randomtask1155/gpdb,foyzur/gpdb,yuanzhao/gpdb,adam8157/gpdb,xuegang/gpdb,royc1/gpdb,adam8157/gpdb,ahachete/gpdb,randomtask1155/gpdb,jmcatamney/gpdb,snaga/postgres-xl,adam8157/gpdb,rvs/gpdb,Chibin/gpdb,arcivanov/postgres-xl,techdragon/Postgres-XL,edespino/gpdb,snaga/postgres-xl,snaga/postgres-xl,lpetrov-pivotal/gpdb,greenplum-db/gpdb,techdragon/Postgres-XL,cjcjameson/gpdb,yuanzhao/gpdb,postmind-net/postgres-xl,50wu/gpdb,yuanzhao/gpdb,chrishajas/gpdb,rvs/gpdb,0x0FFF/gpdb,Chibin/gpdb,techdragon/Postgres-XL,janebeckman/gpdb,xuegang/gpdb,CraigHarris/gpdb,randomtask1155/gpdb,janebeckman/gpdb,Quikling/gpdb,edespino/gpdb,pavanvd/postgres-xl,zeroae/postgres-xl,50wu/gpdb,zaksoup/gpdb,xuegang/gpdb,foyzur/gpdb,rubikloud/gpdb,ashwinstar/gpdb,xuegang/gpdb,50wu/gpdb,kaknikhil/gpdb,randomtask1155/gpdb,0x0FFF/gpdb,50wu/gpdb,Chibin/gpdb,Chibin/gpdb,royc1/gpdb,atris/gpdb,atris/gpdb,0x0FFF/gpdb,50wu/gpdb,Quikling/gpdb,yuanzhao/gpdb,rubikloud/gpdb,foyzur/gpdb,zaksoup/gpdb,chrishajas/gpdb,cjcjameson/gpdb,Postgres-XL/Postgres-XL,xuegang/gpdb,lisakowen/gpdb,oberstet/postgres-xl,0x0FFF/gpdb,xuegang/gpdb,greenplum-db/gpdb,tpostgres-projects/tPostgres,0x0FFF/gpdb,CraigHarris/gpdb,rvs/gpdb,royc1/gpdb,oberstet/postgres-xl,greenplum-db/gpdb,ovr/postgres-xl,edespino/gpdb,janebeckman/gpdb,kaknikhil/gpdb,Postgres-XL/Postgres-XL,cjcjameson/gpdb,rubikloud/gpdb,edespino/gpdb,ashwinstar/gpdb,rubikloud/gpdb,chrishajas/gpdb,lpetrov-pivotal/gpdb,rvs/gpdb,pavanvd/postgres-xl,yuanzhao/gpdb,lisakowen/gpdb,janebeckman/gpdb,lpetrov-pivotal/gpdb,tangp3/gpdb,adam8157/gpdb,postmind-net/postgres-xl,50wu/gpdb,xinzweb/gpdb,50wu/gpdb,greenplum-db/gpdb,ovr/postgres-xl,CraigHarris/gpdb,ashwinstar/gpdb,tpostgres-projects/tPostgres,chrishajas/gpdb,yazun/postgres-xl,arcivanov/postgres-xl,lisakowen/gpdb,cjcjameson/gpdb,CraigHarris/gpdb,tpostgres-projects/tPostgres,zeroae/postgres-xl,edespino/gpdb,xinzweb/gpdb,edespino/gpdb,jmcatamney/gpdb,ahachete/gpdb,lintzc/gpdb,tangp3/gpdb,yazun/postgres-xl,lintzc/gpdb,kmjungersen/PostgresXL,lintzc/gpdb,tpostgres-projects/tPostgres,rubikloud/gpdb,royc1/gpdb,greenplum-db/gpdb,edespino/gpdb,kmjungersen/PostgresXL,yazun/postgres-xl,lintzc/gpdb,rvs/gpdb,foyzur/gpdb,lpetrov-pivotal/gpdb,cjcjameson/gpdb,janebeckman/gpdb,zeroae/postgres-xl,yazun/postgres-xl,kaknikhil/gpdb,randomtask1155/gpdb,lintzc/gpdb,royc1/gpdb,zaksoup/gpdb,0x0FFF/gpdb,lintzc/gpdb,xuegang/gpdb,ashwinstar/gpdb,zaksoup/gpdb,chrishajas/gpdb,lisakowen/gpdb,adam8157/gpdb,greenplum-db/gpdb,adam8157/gpdb,kaknikhil/gpdb,Quikling/gpdb,tangp3/gpdb,yuanzhao/gpdb,rubikloud/gpdb,ashwinstar/gpdb,zaksoup/gpdb,pavanvd/postgres-xl,rvs/gpdb,kaknikhil/gpdb,janebeckman/gpdb,Chibin/gpdb,xinzweb/gpdb,rvs/gpdb,xuegang/gpdb,lpetrov-pivotal/gpdb,lisakowen/gpdb,zeroae/postgres-xl,kaknikhil/gpdb,ashwinstar/gpdb,adam8157/gpdb,Quikling/gpdb,tpostgres-projects/tPostgres,jmcatamney/gpdb,jmcatamney/gpdb,ovr/postgres-xl,lintzc/gpdb,xinzweb/gpdb,yuanzhao/gpdb,royc1/gpdb,kmjungersen/PostgresXL,postmind-net/postgres-xl,chrishajas/gpdb,Quikling/gpdb,Quikling/gpdb,xuegang/gpdb,atris/gpdb,tangp3/gpdb,0x0FFF/gpdb,CraigHarris/gpdb,Chibin/gpdb,oberstet/postgres-xl,lpetrov-pivotal/gpdb,Quikling/gpdb,greenplum-db/gpdb,kaknikhil/gpdb,kmjungersen/PostgresXL,cjcjameson/gpdb,jmcatamney/gpdb,foyzur/gpdb,xinzweb/gpdb,foyzur/gpdb,Quikling/gpdb,chrishajas/gpdb,pavanvd/postgres-xl,janebeckman/gpdb,greenplum-db/gpdb,atris/gpdb,edespino/gpdb,rvs/gpdb,CraigHarris/gpdb,ahachete/gpdb,ahachete/gpdb,Chibin/gpdb,atris/gpdb,snaga/postgres-xl,randomtask1155/gpdb,cjcjameson/gpdb,Postgres-XL/Postgres-XL,ahachete/gpdb,adam8157/gpdb,cjcjameson/gpdb,ahachete/gpdb,cjcjameson/gpdb,rubikloud/gpdb,techdragon/Postgres-XL,techdragon/Postgres-XL,atris/gpdb,postmind-net/postgres-xl,ovr/postgres-xl,jmcatamney/gpdb,Postgres-XL/Postgres-XL,lpetrov-pivotal/gpdb,cjcjameson/gpdb,foyzur/gpdb,zaksoup/gpdb,oberstet/postgres-xl,royc1/gpdb,CraigHarris/gpdb,CraigHarris/gpdb,kaknikhil/gpdb,yuanzhao/gpdb,pavanvd/postgres-xl,lintzc/gpdb,Quikling/gpdb,kaknikhil/gpdb,tangp3/gpdb,Quikling/gpdb,rubikloud/gpdb,yazun/postgres-xl,randomtask1155/gpdb,edespino/gpdb,rvs/gpdb,yuanzhao/gpdb,ashwinstar/gpdb,rvs/gpdb,jmcatamney/gpdb,atris/gpdb,kmjungersen/PostgresXL,oberstet/postgres-xl,kaknikhil/gpdb