Clear output buffer only if it's not empty
Clear output buffer only if it's not empty

TimDix/concrete5,avdevs/concrete5,avdevs/concrete5,TimDix/concrete5,MichaelMaar/concrete5,MichaelMaar/concrete5,matt9mg/concrete5,matt9mg/concrete5,matt9mg/concrete5,MichaelMaar/concrete5,avdevs/concrete5,TimDix/concrete5