Avoiding calling scrollTop() twice

When there is an anchor element referenced by the hash in the URL, we
would call `scrollTop()` first with zero, then with the element
position. Now, ensure that we only call scrollTop once at most.

Author: mislav

jquery.pjax.js

@@ -317,18 +317,17 @@ function pjax(options) {
 
     executeScriptTags(container.scripts)
 
-    // Scroll to top by default
-    if (typeof options.scrollTo === 'number')
-      $(window).scrollTop(options.scrollTo)
+    var scrollTo = options.scrollTo
 
-    // If the URL has a hash in it, make sure the browser
-    // knows to navigate to the hash.
+    // Ensure browser scrolls to the element referenced by the URL anchor
     if (hash) {
       var name = decodeURIComponent(hash.slice(1))
       var target = document.getElementById(name) || document.getElementsByName(name)[0]
-      if (target) $(window).scrollTop($(target).offset().top)
+      if (target) scrollTo = $(target).offset().top
     }
 
+    if (typeof scrollTo == 'number') $(window).scrollTop(scrollTo)
+
     fire('pjax:success', [data, status, xhr, options])
   }