message: fix(animations): avoid animation insertions during router back/refresh
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diff: @@ -666,7 +666,16 @@ export class TransitionAnimationEngine {
  // code does not contain any animation code in it, but it is
  // just being called so that the node is marked as being inserted
  if (namespaceId) {
  - this._fetchNamespace(namespaceId).insertNode(element, parent);
  + const ns = this._fetchNamespace(namespaceId);
  + // This if-statement is a workaround for router issue #21947.
  + // The router sometimes hits a race condition where while a route
  + // is being instantiated a new navigation arrives, triggering leave
  + // animation of DOM that has not been fully initialized, until this
  + // is resolved, we need to handle the scenario when DOM is not in a
  + // consistent state during the animation.
  + if (ns) {
  + ns.insertNode(element, parent);
  + }
  }
  // only *directives and host elements are inserted before
  