Check for NULL values in the put direction of store
Check for NULL values in the put direction of store

This is now flagged as an error instead of causing a segfault.

dafugg/augeas,pevalme/augeas,kunkku/augeas,pevalme/augeas,GeoffWilliams/augeas,raphink/augeas,mlichvar/augeas,ptoscano/augeas,dafugg/augeas,hercules-team/augeas,jasperla/augeas,dafugg/augeas,mlichvar/augeas,bkearney/augeas,GeoffWilliams/augeas,bkearney/augeas,domcleal/augeas,jasperla/augeas,lutter/augeas,manandbytes/augeas,lutter/augeas,domcleal/augeas,camptocamp/augeas,kunkku/augeas,MikaelSmith/augeas,kumy/augeas,jjlin/augeas,MikaelSmith/augeas,hercules-team/augeas,jtopjian/augeas,mlichvar/augeas,raphink/augeas,ptoscano/augeas,jjlin/augeas,hercules-team/augeas-do-not-use,ptoscano/augeas,camptocamp/augeas,mchf/augeas,camptocamp/augeas,bkearney/augeas,hercules-team/augeas-do-not-use,kumy/augeas,kumy/augeas,kunkku/augeas,jjlin/augeas,pevalme/augeas,lutter/augeas,domcleal/augeas,manandbytes/augeas,bkearney/augeas,jtopjian/augeas,kumy/augeas,camptocamp/augeas,hercules-team/augeas-do-not-use,mchf/augeas