add tidy_pstr_trail to neck_cut

diff --git a/src/prolog/machine/machine_state_impl.rs b/src/prolog/machine/machine_state_impl.rs
index 5e2245f5bd19a70b9f886365e5b61a0d65f464ca..6b1015aaa84a57192702bfe1274944d8278f0ab8 100644 (file)
--- a/src/prolog/machine/machine_state_impl.rs
+++ b/src/prolog/machine/machine_state_impl.rs
@@ -2279,6 +2279,7 @@ impl MachineState {
                 if b > b0 {
                     self.b = b0;
                     self.tidy_trail();
+                   self.tidy_pstr_trail();
                     self.or_stack.truncate(self.b);
                 }