--- a/testing/web-platform/meta/MANIFEST.json
+++ b/testing/web-platform/meta/MANIFEST.json
@@ -173264,16 +173264,40 @@
       [
        "/svg/linking/reftests/href-use-element-ref.html",
        "=="
       ]
      ],
      {}
     ]
    ],
+   "svg/linking/reftests/use-descendant-combinator-001.html": [
+    [
+     "/svg/linking/reftests/use-descendant-combinator-001.html",
+     [
+      [
+       "/svg/linking/reftests/use-descendant-combinator-ref.html",
+       "=="
+      ]
+     ],
+     {}
+    ]
+   ],
+   "svg/linking/reftests/use-descendant-combinator-002.html": [
+    [
+     "/svg/linking/reftests/use-descendant-combinator-002.html",
+     [
+      [
+       "/svg/linking/reftests/use-descendant-combinator-ref.html",
+       "=="
+      ]
+     ],
+     {}
+    ]
+   ],
    "svg/shapes/rect-01.svg": [
     [
      "/svg/shapes/rect-01.svg",
      [
       [
        "/svg/shapes/rect-01-ref.html",
        "=="
       ]
@@ -282406,16 +282430,21 @@
      {}
     ]
    ],
    "svg/linking/reftests/href-use-element-ref.html": [
     [
      {}
     ]
    ],
+   "svg/linking/reftests/use-descendant-combinator-ref.html": [
+    [
+     {}
+    ]
+   ],
    "svg/linking/scripted/testScripts/dummyScript.js": [
     [
      {}
     ]
    ],
    "svg/linking/scripted/testScripts/externalScript1.js": [
     [
      {}
@@ -391651,17 +391680,17 @@
    "cbe9305740f7e0a9e8c7be9dbfcb606f8abb2758",
    "support"
   ],
   "XMLHttpRequest/resources/auth2/auth.py": [
    "cbe9305740f7e0a9e8c7be9dbfcb606f8abb2758",
    "support"
   ],
   "XMLHttpRequest/resources/auth2/corsenabled.py": [
-   "a70576e6ae82a030c6776923082e5aa50fad0078",
+   "4136b00b543096216f9f1ad1314c7062dda04179",
    "support"
   ],
   "XMLHttpRequest/resources/auth3/auth.py": [
    "cbe9305740f7e0a9e8c7be9dbfcb606f8abb2758",
    "support"
   ],
   "XMLHttpRequest/resources/auth4/auth.py": [
    "cbe9305740f7e0a9e8c7be9dbfcb606f8abb2758",
@@ -391671,21 +391700,21 @@
    "cb73eae36004b4e939867ae72f8db79e5a14c99c",
    "support"
   ],
   "XMLHttpRequest/resources/auth6/auth.py": [
    "cb73eae36004b4e939867ae72f8db79e5a14c99c",
    "support"
   ],
   "XMLHttpRequest/resources/auth7/corsenabled.py": [
-   "3f8fe382e3aa4ffe0e7c1ecb4571a55866bba27f",
+   "cbc1e4a39cc2e999ef7bd4053a600e8b0d515bb5",
    "support"
   ],
   "XMLHttpRequest/resources/auth8/corsenabled-no-authorize.py": [
-   "c3add811ecf33bf3452fe471d27756dc152db81f",
+   "523fbc134ecfee5b13e4ef93508712847fc4e396",
    "support"
   ],
   "XMLHttpRequest/resources/auth9/auth.py": [
    "cbe9305740f7e0a9e8c7be9dbfcb606f8abb2758",
    "support"
   ],
   "XMLHttpRequest/resources/authentication.py": [
    "e7d0a9054c562964b23c4e4bbf1d1207a1811b55",
@@ -583158,16 +583187,28 @@
   "svg/linking/reftests/href-use-element-ref.html": [
    "8a4977599d6f531a76524191cb9bad75803a455e",
    "support"
   ],
   "svg/linking/reftests/href-use-element.html": [
    "3ee77582da34128b38e8e523c553f943ec0e1947",
    "reftest"
   ],
+  "svg/linking/reftests/use-descendant-combinator-001.html": [
+   "323fde648ee2d065bfd945a2c4d5be86f1c308ff",
+   "reftest"
+  ],
+  "svg/linking/reftests/use-descendant-combinator-002.html": [
+   "3d51ca0fc007d52147e7ea03493cac7ee1bb7903",
+   "reftest"
+  ],
+  "svg/linking/reftests/use-descendant-combinator-ref.html": [
+   "fb8aec792684b97151d2964b85d1e70829e141ad",
+   "support"
+  ],
   "svg/linking/scripted/href-animate-element.html": [
    "c224f6b609079f31c256625417e4677b21b5f71a",
    "testharness"
   ],
   "svg/linking/scripted/href-mpath-element.html": [
    "8b13592c688265576addd27027a18f7aea397580",
    "testharness"
   ],
@@ -585967,17 +586008,17 @@
    "da39a3ee5e6b4b0d3255bfef95601890afd80709",
    "support"
   ],
   "webdriver/tests/element_click/select.py": [
    "5ba51b660c7203bba3ada597c2f56fe094358e1f",
    "wdspec"
   ],
   "webdriver/tests/element_retrieval/get_active_element.py": [
-   "9080770b60a988cb37e30700efb118d392a896c7",
+   "41dab8ecf11556f7b1490d515557de659813881e",
    "wdspec"
   ],
   "webdriver/tests/fullscreen_window.py": [
    "6b1e481aac6856b6e858df17731d037997b99f83",
    "wdspec"
   ],
   "webdriver/tests/get_window_rect.py": [
    "0dc9c8cc1332907be819d52feb7c94f4b1cc928a",
@@ -586095,17 +586136,17 @@
    "5d3ae3da2967072dff274f384cceaecc07b6aa4b",
    "wdspec"
   ],
   "webdriver/tests/support/__init__.py": [
    "5a31a3917a5157516c10951a3b3d5ffb43b992d9",
    "support"
   ],
   "webdriver/tests/support/asserts.py": [
-   "b02f45e99cdee49f12608e60333e566c8c0e04d0",
+   "4e4f29b9d305383e5bcfa01fa1ba789d0c12ef93",
    "support"
   ],
   "webdriver/tests/support/fixtures.py": [
    "4b68fd0f02cc88e9abb422c2c3978812edbbbec7",
    "support"
   ],
   "webdriver/tests/support/http_request.py": [
    "cb40c781fea2280b98135522def5e6a116d7b946",

new file mode 100644
--- /dev/null
+++ b/testing/web-platform/tests/svg/linking/reftests/use-descendant-combinator-001.html
@@ -0,0 +1,28 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>CSS Test: use element doesn't cross shadow tree boundaries in selector-matching</title>
+<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
+<link rel="help" href="https://svgwg.org/svg2-draft/struct.html#UseElement">
+<link rel="match" href="/svg/linking/reftests/use-descendant-combinator-ref.html">
+<style>
+#test rect {
+  stroke: red;
+  stroke-width: 10px;
+}
+</style>
+<p>
+  You should see a green square, and no red.
+</p>
+<svg
+  version="1.1"
+  xmlns="http://www.w3.org/2000/svg"
+  xmlns:xlink="http://www.w3.org/1999/xlink">
+  <defs>
+    <g id="square">
+      <rect width="100" height="100"/>
+    </g>
+  </defs>
+  <g id="test">
+    <use xlink:href="#square" fill="green" />
+  </g>
+</svg>

new file mode 100644
--- /dev/null
+++ b/testing/web-platform/tests/svg/linking/reftests/use-descendant-combinator-002.html
@@ -0,0 +1,33 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>CSS Test: use element doesn't cross shadow tree boundaries in selector-matching</title>
+<link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io">
+<link rel="help" href="https://svgwg.org/svg2-draft/struct.html#UseElement">
+<link rel="match" href="/svg/linking/reftests/use-descendant-combinator-ref.html">
+<style>
+#test rect {
+  stroke: red;
+  stroke-width: 10px;
+}
+.inside-use rect {
+  fill: green;
+}
+</style>
+<p>
+  You should see a green square, and no red.
+</p>
+<svg
+  version="1.1"
+  xmlns="http://www.w3.org/2000/svg"
+  xmlns:xlink="http://www.w3.org/1999/xlink">
+  <defs>
+    <g id="square">
+      <g class="inside-use">
+        <rect width="100" height="100"/>
+      </g>
+    </g>
+  </defs>
+  <g id="test">
+    <use xlink:href="#square" />
+  </g>
+</svg>

new file mode 100644
--- /dev/null
+++ b/testing/web-platform/tests/svg/linking/reftests/use-descendant-combinator-ref.html
@@ -0,0 +1,12 @@
+<!doctype html>
+<meta charset=utf-8>
+<title>CSS Test reference</title>
+<p>
+  You should see a green square, and no red.
+</p>
+<svg
+  version="1.1"
+  xmlns="http://www.w3.org/2000/svg"
+  xmlns:xlink="http://www.w3.org/1999/xlink">
+  <rect width="100" height="100" fill="green"/>
+</svg>