Views Filter, going back to - none - in parent filed returns 0

when users choose parent term in views exposed filter, it works flawlessly, but after searching several things i wanted to display all results again, i chose none in parent, so it returns nothing, in the URL, the filter name is shs, so first time i search for everything without pressing the filter dropdown list
shs=All
then i search for things, shs=24, shs=875
go back to -none-
shs=0 and no results return
how can i make the shs=0 become shs=All

also, a design request. can't we have an empty locked field/s next to the parent filed that gets populated/enabled once a person chooses something?