faulty check for initialPop

[bbken]

When run in Safari 7.0.5, OS X 10.9.4, initialPop is set to false by the following code block.

// Non-webkit browsers don't fire an initial popstate event
if ('state' in window.history) {
  initialPop = false
}

However, https://developer.mozilla.org/en-US/docs/Web/Events/popstate states that an initial popstate event does indeed fire in Safari: "Browsers tend to handle the popstate event differently on page load. Chrome (prior to v34) and Safari always emit a popstate event on page load, but Firefox doesn't." I have confirmed this behavior in my own testing.

Particularly, Safari will sometimes fire the popstate event as the initially loaded JS is executing (the exact timing of the popstate in Safari seems non-deterministic, and based on factors that I have not yet come to understand). Since pjax is unaware that my version of Safari on my version of OS X, performs an initial pop, a pjax request that fires as soon as the page loads will incorrectly be cancelled.

[mislav]

Thanks for reporting. Our initial popstate detection might not be perfect and out automated test for this is even forse (intermittently fails).

Also, if an inital popsate happens before jquery-pjax.js has even loaded, there's no chance that we can even detect it.

Why are you firing a pjax request on page load?

[opensrcken]

In the particular case where this issue was detect, we are firing a pjax request on page load to load the heaviest parts of the page asynchronously. This allows users to see the lighter-weight "frame" of the page quickly, enabling a better user experience.

[zephiransas]

I also have a same case.

So I comment-out like this.

// Non-webkit browsers don't fire an initial popstate event
//if ('state' in window.history) {
//  initialPop = false
//}

This fix looks good on Safari and Chrome. But I can't decide is this correct...
FYI.

[wbinnssmith]

I'm also having this exact issue, and this patch resolves it. Any chance it will be merged? Would be much appreciated!