This is potentially a somewhat oddly specific question.
The situation:
I have a page with a position:fixed
modal dialog (actually several, but that's irrelevant to the problem, as far as I've been able to determine). The modal opens when clicking a certain link. A script listens for hashchange
events in order to close the modal when the user hits the back button.
The expected behaviour is that when back:ing out of the dialog, the page returns to the scroll position where it was before opening the modal. This happens in nearly every modern browser I've tested (desktop FF, Chrome, IE9/10/11 and Safari, and Chrome for Android).
On iPhone/mobile Safari, the page instead scrolls back to the top.
Test code
This is as reduced as I've been able to make it.
<!DOCTYPE html>
<html lang="en">
<head>
<meta http-equiv="content-type" content="text/html, charset=utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>Modal test</title>
</head>
<body>
<h1>Header</h1>
<p>Enough<br>content<br>to<br>cause<br>some<br>scrolling</p>
<br><br><br><br><br><br><br>
<br><br><br><br><br><br><br>
<br><br><br><br><br><br><br>
<h1>Header</h1>
<p><a href="##popup" class="js-open-popup">Open popup</a></p>
<p>Enough<br>content<br>to<br>cause<br>some<br>scrolling<br>
<br><br><br><br><br><br>
<br><br><br><br><br><br>
<br><br><br><br><br><br>
<div id="#popup" style="background:#fff; width:300px; height:100px; border:2px solid #000; position:fixed; top:50px; left:50px; display:none">
Modal dialog.<br>
Hitting 'back' should close this modal.<br><br>
<a href="javascript:void(0)" class="js-close-popup">Close modal</a>
</div>
<script type="text/javascript" src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js"></script>
<script type="text/javascript">
(function($){
$(document).ready(function(){
$('.js-close-popup').click(function(ev){
window.history.back();
return false;
});
$('.js-open-popup').click(function(ev){
$('#\\#popup').fadeIn(400);
});
});
$(window).on('hashchange', function(){
hash = window.location.hash.replace('#','');
if(hash == '' || hash.lastIndexOf('#', 0) !== 0){
$('#\\#popup').fadeOut(400);
}
});
})(jQuery);
</script>
</body>
</html>
What I want to do is kill the scroll-to-top on iPhones, if at all possible without changing too much of the back-button logic for the popups (or breaking something in any other browsers).
I've searched SO for X number of hours but haven't been able to find a mention of this particular problem, or indeed a solution that works. Feel free to slap me on the fingers and point me in the right direction if I've missed an existing thread that answers my question.
EDIT: To clarify, opening the popup works as expected and does not cause any "auto-scroll".