pacf lags

pacf  in  devel seems by default to return a different number of lags 
than 1.7.1 for  $pacf. I don't see any mention of this in the NEWS file, 
or any change in the documentation,  so I suspect it is and error, 
though it may be an undocumented improvement.

(Newbie question:  How is the simplest way to display a function like 
pacf.default that is not exported from a namespace?)

Paul Gilbert