js/libs/ember-1.5.1.js
function(intent, isIntermediate) {

        var wasTransitioning = !!this.activeTransition;
        var oldState = wasTransitioning ? this.activeTransition.state : this.state;
        var newTransition;
        var router = this;

        try {
          var newState = intent.applyToState(oldState, this.recognizer, this.getHandler, isIntermediate);

          if (handlerInfosEqual(newState.handlerInfos, oldState.handlerInfos)) {

            // This is a no-op transition. See if query params changed.
            var queryParamChangelist = getChangelist(oldState.queryParams, newState.queryParams);
            if (queryParamChangelist) {

              // This is a little hacky but we need some way of storing
              // changed query params given that no activeTransition
              // is guaranteed to have occurred.
              this._changedQueryParams = queryParamChangelist.changed;
              trigger(this, newState.handlerInfos, true, ['queryParamsDidChange', queryParamChangelist.changed, queryParamChangelist.all, queryParamChangelist.removed]);
              this._changedQueryParams = null;

              if (!wasTransitioning && this.activeTransition) {
                // One of the handlers in queryParamsDidChange
                // caused a transition. Just return that transition.
                return this.activeTransition;
              } else {
                // Running queryParamsDidChange didn't change anything.
                // Just update query params and be on our way.
                oldState.queryParams = finalizeQueryParamChange(this, newState.handlerInfos, newState.queryParams);

                // We have to return a noop transition that will
                // perform a URL update at the end. This gives
                // the user the ability to set the url update
                // method (default is replaceState).
                newTransition = new Transition(this);
                newTransition.urlMethod = 'replace';
                newTransition.promise = newTransition.promise.then(function(result) {
                  updateURL(newTransition, oldState, true);
                  if (router.didTransition) {
                    router.didTransition(router.currentHandlerInfos);
                  }
                  return result;
                }, null, promiseLabel("Transition complete"));
                return newTransition;
              }
            }

            // No-op. No need to create a new transition.
            return new Transition(this);
          }

          if (isIntermediate) {
            setupContexts(this, newState);
            return;
          }

          // Create a new transition to the destination route.
          newTransition = new Transition(this, intent, newState);

          // Abort and usurp any previously active transition.
          if (this.activeTransition) {
            this.activeTransition.abort();
          }
          this.activeTransition = newTransition;

          // Transition promises by default resolve with resolved state.
          // For our purposes, swap out the promise to resolve
          // after the transition has been finalized.
          newTransition.promise = newTransition.promise.then(function(result) {
            return router.async(function() {
              return finalizeTransition(newTransition, result.state);
            }, "Finalize transition");
          }, null, promiseLabel("Settle transition promise when transition is finalized"));

          if (!wasTransitioning) {
            trigger(this, this.state.handlerInfos, true, ['willTransition', newTransition]);
          }

          return newTransition;
        } catch(e) {
          return new Transition(this, intent, null, e);
        }
      }
function(intent, isIntermediate) {

        var wasTransitioning = !!this.activeTransition;
        var oldState = wasTransitioning ? this.activeTransition.state : this.state;
        var newTransition;
        var router = this;

        try {
          var newState = intent.applyToState(oldState, this.recognizer, this.getHandler, isIntermediate);

          if (handlerInfosEqual(newState.handlerInfos, oldState.handlerInfos)) {

            // This is a no-op transition. See if query params changed.
            var queryParamChangelist = getChangelist(oldState.queryParams, newState.queryParams);
            if (queryParamChangelist) {

              // This is a little hacky but we need some way of storing
              // changed query params given that no activeTransition
              // is guaranteed to have occurred.
              this._changedQueryParams = queryParamChangelist.changed;
              trigger(this, newState.handlerInfos, true, ['queryParamsDidChange', queryParamChangelist.changed, queryParamChangelist.all, queryParamChangelist.removed]);
              this._changedQueryParams = null;

              if (!wasTransitioning && this.activeTransition) {
                // One of the handlers in queryParamsDidChange
                // caused a transition. Just return that transition.
                return this.activeTransition;
              } else {
                // Running queryParamsDidChange didn't change anything.
                // Just update query params and be on our way.
                oldState.queryParams = finalizeQueryParamChange(this, newState.handlerInfos, newState.queryParams);

                // We have to return a noop transition that will
                // perform a URL update at the end. This gives
                // the user the ability to set the url update
                // method (default is replaceState).
                newTransition = new Transition(this);
                newTransition.urlMethod = 'replace';
                newTransition.promise = newTransition.promise.then(function(result) {
                  updateURL(newTransition, oldState, true);
                  if (router.didTransition) {
                    router.didTransition(router.currentHandlerInfos);
                  }
                  return result;
                }, null, promiseLabel("Transition complete"));
                return newTransition;
              }
            }

            // No-op. No need to create a new transition.
            return new Transition(this);
          }

          if (isIntermediate) {
            setupContexts(this, newState);
            return;
          }

          // Create a new transition to the destination route.
          newTransition = new Transition(this, intent, newState);

          // Abort and usurp any previously active transition.
          if (this.activeTransition) {
            this.activeTransition.abort();
          }
          this.activeTransition = newTransition;

          // Transition promises by default resolve with resolved state.
          // For our purposes, swap out the promise to resolve
          // after the transition has been finalized.
          newTransition.promise = newTransition.promise.then(function(result) {
            return router.async(function() {
              return finalizeTransition(newTransition, result.state);
            }, "Finalize transition");
          }, null, promiseLabel("Settle transition promise when transition is finalized"));

          if (!wasTransitioning) {
            trigger(this, this.state.handlerInfos, true, ['willTransition', newTransition]);
          }

          return newTransition;
        } catch(e) {
          return new Transition(this, intent, null, e);
        }
      }
NOTE: this doesn't really belong here, but here it shall remain until our ES6 transpiler can handle cyclical deps.