Weak acid buffer consist of a weak acid, HA and a salt of the acid's conjugate base, NaA.
HA(aq) <----> H+ + A-
NaA ----> Na+ + A-
Due to the dissociation of NaA, there will be large reservoir of A-, this shifts equilibrium of the acid dissociation to the left. So at equilibrium, there will be large reversoir of HA acid, A-(from the salt), little amount of H+, from what i heard the equilibrium to the left shifts up to 97%, so H+ is almost negligible, even if it does reacts with the OH-, it will form H2O, but probably only a small amount.