Merge branch 'conflict_tracking' into links

# Conflicts:
#	src/cargo/core/resolver/mod.rs

diff --cc src/cargo/core/resolver/mod.rs
index 9f7068dbc3369afc858cc8014be49186d625496d,633ae25603386d870183290aa2f180d01e72a5e7..45a8747b262f8ad6af4517ebc09679cdb790097d
--- 1/src/cargo/core/resolver/mod.rs
--- 2/src/cargo/core/resolver/mod.rs
+++ b/src/cargo/core/resolver/mod.rs
@@@ -681,11 -660,10 +679,10 @@@ fn activate_deps_loop<'a>(mut cx: Conte
                     dep.name(), prev_active.len());
              let mut candidates = RemainingCandidates {
                  remaining: RcVecIter::new(Rc::clone(&candidates)),
 -                conflicting_prev_active: HashSet::new(),
 +                conflicting_prev_active: HashMap::new(),
              };
-             conflicting_activations = HashMap::new();
 -            (candidates.next(prev_active),
 -             candidates.clone().next(prev_active).is_ok(),
 +            (candidates.next(prev_active, &cx.links),
 +             candidates.clone().next(prev_active, &cx.links).is_ok(),
               candidates)
          };