Upstream the test for bug 1495791 to WPT.
Differential Revision: https://phabricator.services.mozilla.com/D12427
bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1508645
gecko-commit: 2584f7a7f63adb79ce5acd99bbb91f6b64b87f0f
gecko-integration-branch: mozilla-inbound
gecko-reviewers: aosmond
diff --git a/css/css-masking/clip/clip-fixed-pos-transform-descendant-001-ref.html b/css/css-masking/clip/clip-fixed-pos-transform-descendant-001-ref.html
new file mode 100644
index 0000000..ed78cb7
--- /dev/null
+++ b/css/css-masking/clip/clip-fixed-pos-transform-descendant-001-ref.html
@@ -0,0 +1,11 @@
+<!doctype html>
+<title>CSS Test Reference</title>
+<style>
+ html, body { margin: 0 }
+ div {
+ width: 100px;
+ height: 100px;
+ background: lime;
+ }
+</style>
+<div></div>
diff --git a/css/css-masking/clip/clip-fixed-pos-transform-descendant-001.html b/css/css-masking/clip/clip-fixed-pos-transform-descendant-001.html
new file mode 100644
index 0000000..395b0bc
--- /dev/null
+++ b/css/css-masking/clip/clip-fixed-pos-transform-descendant-001.html
@@ -0,0 +1,38 @@
+<!doctype html>
+<title>CSS Masking: Transformed descendants of a fixed pos element under a clipped element get properly clipped</title>
+<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
+<link rel="author" title="Mozilla" href="https://mozilla.org">
+<link rel="match" href="clip-fixed-pos-transform-descendant-001-ref.html">
+<link rel="help" href="https://drafts.fxtf.org/css-masking/#clip-property">
+<link rel="help" href="https://bugzilla.mozilla.org/show_bug.cgi?id=1495791">
+<style>
+html, body { margin: 0; }
+
+#clip {
+ height: 100px;
+ width: 100px;
+ background: lime;
+ clip: rect(0, auto, auto, 0);
+ position: absolute;
+}
+
+#fixed {
+ position: fixed;
+ top: 0;
+ left: 0;
+ width: 100px;
+ height: 100px;
+}
+
+#clipped {
+ height: 100px;
+ width: 100px;
+ background: red;
+ transform: translateY(100px);
+}
+</style>
+<div id="clip">
+ <div id="fixed">
+ <div id="clipped"></div>
+ </div>
+</div>
