title: React/Redux + super agent, first call gets terminated
body: <p>I am writing a react-redux app where I am making some service calls in my middlewares using superagent. I have found a very strange behavior where the first call to my search api always gets terminated. I have tried waiting 10-30 seconds before making the first call, and logging every step along the process and I cannot seem to pinpoint why this is happening.</p>
  
  <p>My action creator looks like </p>
  
  <pre><code>export function getSearchResults(searchQuery) {
  return {
          query: searchQuery,
          type: actions.GO_TO_SEARCH_RESULTS
      }
  }
  </code></pre>
  
  <p>It hits the middleware logic here :</p>
  
  <pre><code>var defaultURL = '/myServer/mySearch';
  
  callPendingAction();
  
  superagent.get(defaultURL)
          .query({query: action.query})
          .end(requestDone);
  
  
  //sets state pending so we can use loading spinner
  function callPendingAction() {
      action.middlewares.searchIRC.readyState = READY_STATES.PENDING;
      next(action);
  }
  
  //return error or response accordingly
  function requestDone(err, response) {
      console.log("call error", err);
      const search = action.search;
      if (err) {
          search.readyState = READY_STATES.FAILURE;
          if (response) {
              search.error = response.err;
          } else if (err.message) {
              search.error = err.message;
          } else {
              search.error = err;
          }
      } else {
          search.readyState = READY_STATES.SUCCESS;
          search.results = fromJS(response.body);
      }
      return next(action);
  }
  </code></pre>
  
  <p>The query is correct even when the call is terminated, I get this err message back : </p>
  
  <pre><code>Request has been terminated
  Possible causes: the network is offline, Origin is not allowed by Access-Control-Allow-Origin, the page is being unloaded, etc.
  at Request.crossDomainError (http://localhost:8000/bundle.js:28339:14)
  at XMLHttpRequest.xhr.onreadystatechange (http://localhost:8000/bundle.js:28409:20)
  </code></pre>
  
  <p>It appears the page refreshes each time too.</p>
  
  <p>I cannot seem to find any clues as to why this happens, it seems not matter what the first call fails, but then it is fine after that first terminated call. Would appreciate any input, thanks!</p>
  
  <p><strong>UPDATE</strong>: so it seems this is related to chrome, I am on <code>Version 47.0.2526.80 (64-bit)</code>. This app is an iframe within another app and I believe that is causing a problem with chrome because when I try this in firefox there is no issue. What is strange is only the first call gives the CORS issue, then it seems to be corrected after that. If anyone has input or a workaround, I would greatly appreciate it. Thanks for reading.</p>