Work around an ICE due to autoderef.

This is a workaround for rust-lang/rust#17810.

Author: sebcrozet

src/partitioning/dbvt.rs

@@ -44,7 +44,7 @@ DBVT<B, BV> {
     pub fn remove(&mut self, leaf: &mut Rc<RefCell<DBVTLeaf<B, BV>>>) {
         let self_tree = self.tree.take().unwrap();
 
-        let mut bleaf = leaf.borrow_mut();
+        let mut bleaf = (*leaf).borrow_mut();
         self.tree = bleaf.unlink(&mut self.cache, self_tree);
         self.len  = self.len - 1;
     }
@@ -267,9 +267,7 @@ impl<B: 'static, BV: Translation<Vect> + 'static> DBVTLeaf<B, BV> {
                     match other {
                         Internal(ref mut i) => i.parent = pp,
                         Leaf(ref mut l)     => {
-                            // FIXME: if deref_mut is not called, the type inference seems to be
-                            // buggy
-                            l.borrow_mut().deref_mut().parent =
+                            (**l).borrow_mut().parent =
                                 if is_p_right_to_pp { RightChildOf(pp) } else { LeftChildOf(pp) }
                         },
                         Invalid             => unreachable!()
@@ -295,9 +293,7 @@ impl<B: 'static, BV: Translation<Vect> + 'static> DBVTLeaf<B, BV> {
                 // the root changes to the other child
                 match other {
                     Internal(ref mut i) => i.parent = ptr::null_mut(),
-                                           // FIXME: if deref_mut is not called, the type inference seems to be
-                                           // buggy
-                    Leaf(ref l)         => l.borrow_mut().deref_mut().parent = Detached,
+                    Leaf(ref l)         => (**l).borrow_mut().parent = Detached,
                     Invalid             => unreachable!()
                 }
 
@@ -367,7 +363,7 @@ impl<BV: 'static + BoundingVolume + Translation<Vect> + Clone, B: 'static + Clon
               to_insert: Rc<RefCell<DBVTLeaf<B, BV>>>)
               -> Box<DBVTInternal<B, BV>> {
 
-        let mut bto_insert = to_insert.borrow_mut();
+        let mut bto_insert = (*to_insert).borrow_mut();
         let pto_insert     = bto_insert.deref_mut();
 
         match self {
@@ -415,7 +411,7 @@ impl<BV: 'static + BoundingVolume + Translation<Vect> + Clone, B: 'static + Clon
                                 parent = &mut **ci as *mut DBVTInternal<B, BV>;
                             },
                             Leaf(ref l) => {
-                                let mut bl       = l.borrow_mut();
+                                let mut bl       = (**l).borrow_mut();
                                 let     pl       = bl.deref_mut();
                                 let mut internal = cache.alloc(DBVTInternal::new(
                                     pl.bounding_volume.merged(&pto_insert.bounding_volume),
@@ -444,7 +440,7 @@ impl<BV: 'static + BoundingVolume + Translation<Vect> + Clone, B: 'static + Clon
             },
             Leaf(l) => {
                 let     cl = l.clone();
-                let mut bl = cl.borrow_mut();
+                let mut bl = (*cl).borrow_mut();
                 let     pl = bl.deref_mut();
 
                 // create the root