do not consult union-find during fudge_regions_if_ok

Author: nikomatsakis

src/librustc/infer/fudge.rs

@@ -135,19 +135,11 @@ impl<'a, 'gcx, 'tcx> TypeFolder<'gcx, 'tcx> for RegionFudger<'a, 'gcx, 'tcx> {
                         ty
                     }
 
-                    Some(info) => {
+                    Some(&origin) => {
                         // This variable was created during the
-                        // fudging; it was mapped the root
-                        // `root_vid`. There are now two
-                        // possibilities: either the root was creating
-                        // during the fudging too, in which case we
-                        // want a fresh variable, or it was not, in
-                        // which case we can return it.
-                        if self.type_variables.contains_key(&info.root_vid) {
-                            self.infcx.next_ty_var(info.root_origin)
-                        } else {
-                            self.infcx.tcx.mk_var(info.root_vid)
-                        }
+                        // fudging. Recreate it with a fresh variable
+                        // here.
+                        self.infcx.next_ty_var(origin)
                     }
                 }
             }

src/librustc/infer/type_variable.rs

@@ -67,12 +67,7 @@ pub enum TypeVariableOrigin {
     Generalized(ty::TyVid),
 }
 
-pub type TypeVariableMap = FxHashMap<ty::TyVid, TypeVariableInfo>;
-
-pub struct TypeVariableInfo {
-    pub root_vid: ty::TyVid,
-    pub root_origin: TypeVariableOrigin,
-}
+pub type TypeVariableMap = FxHashMap<ty::TyVid, TypeVariableOrigin>;
 
 struct TypeVariableData<'tcx> {
     value: TypeVariableValue<'tcx>,
@@ -294,8 +289,6 @@ impl<'tcx> TypeVariableTable<'tcx> {
     /// along with their origin.
     pub fn types_created_since_snapshot(&mut self, s: &Snapshot) -> TypeVariableMap {
         let actions_since_snapshot = self.values.actions_since_snapshot(&s.snapshot);
-        let eq_relations = &mut self.eq_relations;
-        let values = &self.values;
 
         actions_since_snapshot
             .iter()
@@ -304,9 +297,8 @@ impl<'tcx> TypeVariableTable<'tcx> {
                 _ => None,
             })
             .map(|vid| {
-                let root_vid = eq_relations.find(vid);
-                let root_origin = values.get(vid.index as usize).origin.clone();
-                (vid, TypeVariableInfo { root_vid, root_origin })
+                let origin = self.values.get(vid.index as usize).origin.clone();
+                (vid, origin)
             })
             .collect()
     }