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Test Info:
Services.scriptloader.loadSubScript(
this
);
Services.scriptloader.loadSubScript(
this
);
add_task(async function test_main() {
// Open a specific page in a background tab, then switch to the tab, check if
// the visual and layout scroll offsets have diverged.
// Then change to another tab so it's background again. Then reload it. Then
// change back to it and check again if the visual and layout scroll offsets
// have diverged.
// The page has a couple important properties to trigger the bug. We need to
// be restoring a non-zero scroll position so that we call ScrollToImpl with
// origin restore so that we do not set the visual viewport offset. We then
// need to call ScrollToImpl with a origin that does not get clobber by apz
// so that we (wrongly) set the visual viewport offset.
requestLongerTimeout(2);
async function twoRafsInContent(browser) {
await SpecialPowers.spawn(browser, [], async function () {
await new Promise(r =>
content.requestAnimationFrame(() => content.requestAnimationFrame(r))
);
});
}
async function waitForApzInContent(browser) {
await SpecialPowers.spawn(browser, [], async () => {
await content.wrappedJSObject.waitUntilApzStable();
await content.wrappedJSObject.promiseApzFlushedRepaints();
});
}
async function checkScrollPosInContent(browser, iter, num) {
let visualScrollPos = await SpecialPowers.spawn(browser, [], function () {
const offsetX = {};
const offsetY = {};
SpecialPowers.getDOMWindowUtils(content).getVisualViewportOffset(
offsetX,
offsetY
);
return offsetY.value;
});
let scrollPos = await SpecialPowers.spawn(browser, [], function () {
return content.window.scrollY;
});
// When this fails the difference is at least 10000.
ok(
Math.abs(scrollPos - visualScrollPos) < 2,
"expect scroll position and visual scroll position to be the same: visual " +
visualScrollPos +
" scroll " +
scrollPos +
" (" +
iter +
"," +
num +
")"
);
}
for (let i = 0; i < 5; i++) {
let blankurl = "about:blank";
let blankTab = BrowserTestUtils.addTab(gBrowser, blankurl);
let blankbrowser = blankTab.linkedBrowser;
await BrowserTestUtils.browserLoaded(blankbrowser, false, blankurl);
let url =
"http://mochi.test:8888/browser/gfx/layers/apz/test/mochitest/helper_background_tab_load_scroll.html";
let backgroundTab = BrowserTestUtils.addTab(gBrowser, url);
let browser = backgroundTab.linkedBrowser;
await BrowserTestUtils.browserLoaded(browser, false, url);
dump("Done loading background tab\n");
await twoRafsInContent(browser);
// Switch to the foreground.
await BrowserTestUtils.switchTab(gBrowser, backgroundTab);
dump("Switched background tab to foreground\n");
await waitForApzInContent(browser);
await checkScrollPosInContent(browser, i, 1);
await BrowserTestUtils.switchTab(gBrowser, blankTab);
browser.reload();
await BrowserTestUtils.browserLoaded(browser, false, url);
await twoRafsInContent(browser);
// Switch to the foreground.
await BrowserTestUtils.switchTab(gBrowser, backgroundTab);
dump("Switched background tab to foreground\n");
await waitForApzInContent(browser);
await checkScrollPosInContent(browser, i, 2);
// Cleanup
let tabClosed = BrowserTestUtils.waitForTabClosing(backgroundTab);
BrowserTestUtils.removeTab(backgroundTab);
await tabClosed;
let blanktabClosed = BrowserTestUtils.waitForTabClosing(blankTab);
BrowserTestUtils.removeTab(blankTab);
await blanktabClosed;
}
});