author Cosmin Sabou <>
Sun, 05 Feb 2023 19:37:33 +0000
changeset 651812 d8601249f1eb8c52c742b0c19c9ca0fa8f2e31fe
parent 572521 ed5c38a59629d53b960a6973b4d16b8b959884f8
permissions -rw-r--r--
Bug 1806090 - temporarily disable browser_quickactions.js on linux for frequent failures. r=intermittent-reviewers,MasterWayZ Differential Revision:

  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width; initial-scale=1.0">
  <title>Dragging the mouse on a scrollbar for a scrollframe inside nested transforms with a scale component</title>
  <script type="application/javascript" src="apz_test_native_event_utils.js"></script>
  <script type="application/javascript" src="apz_test_utils.js"></script>
  <script src="/tests/SimpleTest/paint_listener.js"></script>
  <script type="text/javascript">

async function test() {
  var scrollableDiv = document.getElementById("scrollable");
  let scrollPromise = new Promise(resolve => {
    scrollableDiv.addEventListener("scroll", resolve, {once: true});

  // Scroll down a small amount (7px). The bug in this case is that the
  // scrollthumb "jumps" most of the way down the scroll track because with
  // the bug, the code was incorrectly combining the transforms.
  // Given the scrollable height of 0.7*2000px and scrollframe height of 0.7*400px,
  // the scrollthumb should be approximately 0.7*80px = 56px tall. Dragging it 7px
  // should scroll approximately 50 (unscaled) pixels. If the bug manifests, it will get
  // dragged by a lot more and scroll to approximately 1300px.
  var dragFinisher = await promiseVerticalScrollbarDrag(scrollableDiv, 7, 7, 0.7);
  if (!dragFinisher) {
    ok(true, "No scrollbar, can't do this test");

  // the events above might be stuck in APZ input queue for a bit until the
  // layer is activated, so we wait here until the scroll event listener is
  // triggered.
  await scrollPromise;

  await dragFinisher();

  // Flush everything just to be safe
  await promiseOnlyApzControllerFlushed();

  // Ensure the scroll position ended up roughly where we wanted it (around
  // 50px, but definitely less than 1300px).
  ok(scrollableDiv.scrollTop < 100, "Scrollbar drag resulted in a scroll position of " + scrollableDiv.scrollTop);

.then(subtestDone, subtestFailed);

    <div style="width: 500px; height: 300px; transform: translate(500px, 500px) scale(0.7)">
        <div id="scrollable" style="transform: translate(-600px, -600px); overflow: scroll">
            <div style="width: 600px; height: 400px">
                <div style="width: 600px; height: 2000px; background-image: linear-gradient(red,blue)"></div>