From d5950821e2eab68ef3d42fa62a40ed102d86c261 Mon Sep 17 00:00:00 2001
From: Richard Schreiber <wiffbi@gmail.com>
Date: Fri, 19 Feb 2021 11:02:42 +0100
Subject: [PATCH] optimized update() to only check the least number of
 checkboxes

---
 src/pretix/static/pretixcontrol/js/ui/main.js | 26 +++++++++----------
 1 file changed, 12 insertions(+), 14 deletions(-)

diff --git a/src/pretix/static/pretixcontrol/js/ui/main.js b/src/pretix/static/pretixcontrol/js/ui/main.js
index 7c9069c77..93c36fe8a 100644
--- a/src/pretix/static/pretixcontrol/js/ui/main.js
+++ b/src/pretix/static/pretixcontrol/js/ui/main.js
@@ -738,22 +738,20 @@ $(function () {
         });
 
         var update = function () {
-            var all_true = true;
-            var all_false = true;
-            $toggle.closest("table").find("td:first-child input[type=checkbox]").each(function () {
-                if ($(this).prop("checked")) {
-                    all_false = false;
-                } else {
-                    all_true = false;
+            var all_same;
+            var checkboxes = $checkboxes.toArray();
+            var i = checkboxes.length;
+            while (i--) {
+                if (all_same === undefined) {
+                    all_same = checkboxes[i].checked;
+                    continue;
+                }
+                if (all_same != checkboxes[i].checked) {
+                    $toggle.prop("checked", false).prop("indeterminate", true);
+                    return;
                 }
-            });
-            if (all_true) {
-                $toggle.prop("checked", true).prop("indeterminate", false);
-            } else if (all_false) {
-                $toggle.prop("checked", false).prop("indeterminate", false);
-            } else {
-                $toggle.prop("checked", false).prop("indeterminate", true);
             }
+            $toggle.prop("checked", all_same).prop("indeterminate", false);
         };
 
         $(this).closest("table").find("td:first-child input[type=checkbox]").change(update);