Merge branch 'upstream' into tab-keyboard-accessibility

bookwyrm/static/js/shared.js

@@ -31,15 +31,25 @@ window.onload = function() {
     // polling
     document.querySelectorAll('[data-poll]')
         .forEach(el => polling(el));
+
+    // browser back behavior
+    document.querySelectorAll('[data-back]')
+        .forEach(t => t.onclick = back);
 };
 
-function polling(el) {
-    let delay = 10000 + (Math.random() * 1000);
+function back(e) {
+    e.preventDefault();
+    history.back();
+}
+
+function polling(el, delay) {
+    delay = delay || 10000;
+    delay += (Math.random() * 1000);
     setTimeout(function() {
         fetch('/api/updates/' + el.getAttribute('data-poll'))
             .then(response => response.json())
             .then(data => updateCountElement(el, data));
-        polling(el);
+        polling(el, delay * 1.25);
     }, delay, el);
 }