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<!doctype html>
<meta charset="utf-8">
<title>
Test for bug 1519371: We don't reframe for changes that affect our containing
block status unless whether we're a containing block really changed.
</title>
<link rel="author" href="mailto:emilio@crisal.io" title="Emilio Cobos Álvarez">
<script src="/tests/SimpleTest/SimpleTest.js"></script>
<div id="content"></div>
<script>
SimpleTest.waitForExplicitFinish();
const utils = SpecialPowers.getDOMWindowUtils(window);
function expectReframe(shouldHaveReframed, callback) {
document.documentElement.offsetTop;
const previousConstructCount = utils.framesConstructed;
const previousRestyleGeneration = utils.restyleGeneration;
callback();
document.documentElement.offsetTop;
isnot(previousRestyleGeneration, utils.restyleGeneration,
"We should have restyled");
(shouldHaveReframed ? isnot : is)(previousConstructCount,
utils.framesConstructed,
`We should ${shouldHaveReframed ? "" : "not"} have reframed`);
}
const content = document.getElementById("content");
// Without fixed-pos descendants, we should not reframe.
expectReframe(false, () => {
content.style.transform = "scale(1)";
});
content.style.transform = "";
content.innerHTML = `<div style="position: fixed"></div>`;
// With fixed-pos descendants, got to reframe.
expectReframe(true, () => {
content.style.transform = "scale(1)";
});
// If our containing-block-ness didn't change, we should not need to reframe.
expectReframe(false, () => {
content.style.willChange = "transform";
});
// If it does change, we need to reframe.
expectReframe(true, () => {
content.style.willChange = "";
content.style.transform = "";
});
SimpleTest.finish();
</script>