From c5c7a1f47af9f80ea81a14f415cc28ab5cece3fb Mon Sep 17 00:00:00 2001
From: WPT Sync Bot <josh+wptsync@joshmatthews.net>
Date: Sat, 8 Dec 2018 20:32:47 -0500
Subject: [PATCH] Update web-platform-tests to revision
 5349c6a6327372f856ecbe07d863d468a4236726

---
 tests/wpt/metadata/MANIFEST.json              |  47 ++-
 .../encoding/single-byte-decoder.html.ini     |   8 +-
 .../navigating-across-documents/006.html.ini  |   4 +
 .../traverse_the_history_5.html.ini           |   4 +
 .../event_timeupdate_noautoplay.html.ini      |   2 +-
 .../viewport-change.html.ini                  |  15 +-
 .../non-active-document.html.ini              |  10 -
 .../the-details-element/toggleEvent.html.ini  |   7 -
 .../aborted-parser.window.js.ini              |   3 +
 .../quirks/unitless-length/quirks.html.ini    | 283 ++++++++++++++++++
 .../semantics/multiple-workers/005.html.ini   |   1 -
 .../infrastructure/testdriver/file_upload.py  |   2 +
 .../testdriver/file_upload.sub.html           |  26 ++
 .../testdriver/file_upload_data.txt           |   1 +
 .../web-platform-tests/interfaces/webxr.idl   |  22 +-
 .../wptrunner/wptrunner/browsers/firefox.py   |   2 +-
 .../docroot/subdir/sub_path.sub.txt           |   3 +
 .../wptserve/tests/functional/test_pipes.py   |   9 +
 .../tools/wptserve/wptserve/pipes.py          |  17 ++
 19 files changed, 427 insertions(+), 39 deletions(-)
 create mode 100644 tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/006.html.ini
 create mode 100644 tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini
 delete mode 100644 tests/wpt/metadata/html/semantics/embedded-content/the-img-element/non-active-document.html.ini
 delete mode 100644 tests/wpt/metadata/html/semantics/interactive-elements/the-details-element/toggleEvent.html.ini
 create mode 100644 tests/wpt/metadata/quirks/unitless-length/quirks.html.ini
 create mode 100644 tests/wpt/web-platform-tests/infrastructure/testdriver/file_upload.py
 create mode 100644 tests/wpt/web-platform-tests/infrastructure/testdriver/file_upload.sub.html
 create mode 100644 tests/wpt/web-platform-tests/infrastructure/testdriver/file_upload_data.txt
 create mode 100644 tests/wpt/web-platform-tests/tools/wptserve/tests/functional/docroot/subdir/sub_path.sub.txt

diff --git a/tests/wpt/metadata/MANIFEST.json b/tests/wpt/metadata/MANIFEST.json
index 54d82a98ee7..e9e3f794192 100644
--- a/tests/wpt/metadata/MANIFEST.json
+++ b/tests/wpt/metadata/MANIFEST.json
@@ -297779,6 +297779,16 @@
      {}
     ]
    ], 
+   "infrastructure/testdriver/file_upload.py": [
+    [
+     {}
+    ]
+   ], 
+   "infrastructure/testdriver/file_upload_data.txt": [
+    [
+     {}
+    ]
+   ], 
    "infrastructure/webdriver/tests/conftest.py": [
     [
      {}
@@ -317514,6 +317524,11 @@
      {}
     ]
    ], 
+   "tools/wptserve/tests/functional/docroot/subdir/sub_path.sub.txt": [
+    [
+     {}
+    ]
+   ], 
    "tools/wptserve/tests/functional/docroot/test.asis": [
     [
      {}
@@ -378697,6 +378712,14 @@
      }
     ]
    ], 
+   "infrastructure/testdriver/file_upload.sub.html": [
+    [
+     "/infrastructure/testdriver/file_upload.sub.html", 
+     {
+      "testdriver": true
+     }
+    ]
+   ], 
    "infrastructure/testdriver/send_keys.html": [
     [
      "/infrastructure/testdriver/send_keys.html", 
@@ -632202,6 +632225,18 @@
    "37721ad9ef3df10f8cdc1da74c27a2259d4601f6", 
    "testharness"
   ], 
+  "infrastructure/testdriver/file_upload.py": [
+   "32633679a9f33d516398f811d888cabf9b062b90", 
+   "support"
+  ], 
+  "infrastructure/testdriver/file_upload.sub.html": [
+   "29c42b49f1716200ef6b68eda4fefd716441fcd8", 
+   "testharness"
+  ], 
+  "infrastructure/testdriver/file_upload_data.txt": [
+   "097d2a3a3f31dbd8f14cff73974cf042b6ebfcd2", 
+   "support"
+  ], 
   "infrastructure/testdriver/send_keys.html": [
    "2170347c9729564f7e492009b3d20b3267422c1d", 
    "testharness"
@@ -632807,7 +632842,7 @@
    "support"
   ], 
   "interfaces/webxr.idl": [
-   "7f7b43c222bd3bc4dcab0c618402ff8ff61ae470", 
+   "27ee27493aaa98869c9fe3adc0f4f19ec99e85e2", 
    "support"
   ], 
   "interfaces/worklets.idl": [
@@ -671035,7 +671070,7 @@
    "support"
   ], 
   "tools/wptrunner/wptrunner/browsers/firefox.py": [
-   "59f06699b585f88c2e2723c74b41f75f03beb754", 
+   "26d744749e534e79c02569ebc235b35c4baccbd6", 
    "support"
   ], 
   "tools/wptrunner/wptrunner/browsers/ie.py": [
@@ -671574,6 +671609,10 @@
    "3b42b29be95174007e1ed18fc10eccdedd80b581", 
    "support"
   ], 
+  "tools/wptserve/tests/functional/docroot/subdir/sub_path.sub.txt": [
+   "44027f2855eb6b95daf7e34c4269444d88166245", 
+   "support"
+  ], 
   "tools/wptserve/tests/functional/docroot/test.asis": [
    "b05ba7da80932036cef863a541d9f417ebd0dcf6", 
    "support"
@@ -671623,7 +671662,7 @@
    "support"
   ], 
   "tools/wptserve/tests/functional/test_pipes.py": [
-   "693cb82e2410b6a66ce15085fb91218f04eb683c", 
+   "2ba6f744b228763659db3dcce1abf1e8ba91f0c5", 
    "support"
   ], 
   "tools/wptserve/tests/functional/test_request.py": [
@@ -671675,7 +671714,7 @@
    "support"
   ], 
   "tools/wptserve/wptserve/pipes.py": [
-   "bb24cd310068a953bec34ac6d224e42bae3ddb3e", 
+   "92b284c93e3f8be26157afebb28af33bedc3e8a1", 
    "support"
   ], 
   "tools/wptserve/wptserve/ranges.py": [
diff --git a/tests/wpt/metadata/encoding/single-byte-decoder.html.ini b/tests/wpt/metadata/encoding/single-byte-decoder.html.ini
index ccd5194185c..39e2173124c 100644
--- a/tests/wpt/metadata/encoding/single-byte-decoder.html.ini
+++ b/tests/wpt/metadata/encoding/single-byte-decoder.html.ini
@@ -532,7 +532,7 @@
     expected: FAIL
 
   [windows-1252: iso_8859-1:1987 (XMLHttpRequest)]
-    expected: FAIL
+    expected: TIMEOUT
 
   [windows-1254: iso_8859-9:1989 (XMLHttpRequest)]
     expected: TIMEOUT
@@ -636,5 +636,11 @@
   [windows-1252: l1 (XMLHttpRequest)]
     expected: TIMEOUT
 
+  [windows-1252: iso88591 (XMLHttpRequest)]
+    expected: TIMEOUT
+
+  [windows-1252: iso8859-1 (XMLHttpRequest)]
+    expected: TIMEOUT
+
 
 [single-byte-decoder.html?TextDecoder]
diff --git a/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/006.html.ini b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/006.html.ini
new file mode 100644
index 00000000000..c8544361068
--- /dev/null
+++ b/tests/wpt/metadata/html/browsers/browsing-the-web/navigating-across-documents/006.html.ini
@@ -0,0 +1,4 @@
+[006.html]
+  [Link with onclick form submit and href navigation ]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini
new file mode 100644
index 00000000000..dc2e45516de
--- /dev/null
+++ b/tests/wpt/metadata/html/browsers/history/the-history-interface/traverse_the_history_5.html.ini
@@ -0,0 +1,4 @@
+[traverse_the_history_5.html]
+  [Multiple history traversals, last would be aborted]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/html/semantics/embedded-content/media-elements/event_timeupdate_noautoplay.html.ini b/tests/wpt/metadata/html/semantics/embedded-content/media-elements/event_timeupdate_noautoplay.html.ini
index 22d1f1d6900..a6f7ac6f249 100644
--- a/tests/wpt/metadata/html/semantics/embedded-content/media-elements/event_timeupdate_noautoplay.html.ini
+++ b/tests/wpt/metadata/html/semantics/embedded-content/media-elements/event_timeupdate_noautoplay.html.ini
@@ -5,5 +5,5 @@
     expected: NOTRUN
 
   [calling play() on a sufficiently long video should trigger timeupdate event]
-    expected: NOTRUN
+    expected: FAIL
 
diff --git a/tests/wpt/metadata/html/semantics/embedded-content/the-img-element/environment-changes/viewport-change.html.ini b/tests/wpt/metadata/html/semantics/embedded-content/the-img-element/environment-changes/viewport-change.html.ini
index 8c50bd0c259..6b57ca778ee 100644
--- a/tests/wpt/metadata/html/semantics/embedded-content/the-img-element/environment-changes/viewport-change.html.ini
+++ b/tests/wpt/metadata/html/semantics/embedded-content/the-img-element/environment-changes/viewport-change.html.ini
@@ -2,14 +2,23 @@
   type: testharness
   expected: TIMEOUT
   [picture: source (max-width:500px) broken image, img valid image, resize to wide]
-    expected: FAIL
+    expected: TIMEOUT
 
   [picture: source (max-width:500px) valid image, img valid image, resize to wide]
-    expected: FAIL
+    expected: TIMEOUT
 
   [picture: source (max-width:500px) valid image, img broken image, resize to narrow]
     expected: TIMEOUT
 
   [picture: source (max-width:500px) valid image, img valid image, resize to narrow]
-    expected: TIMEOUT
+    expected: FAIL
+
+  [picture: source (max-width:500px) broken image, img valid image, resize to narrow]
+    expected: FAIL
+
+  [img (srcset 1 cand) valid image, resize to narrow]
+    expected: FAIL
+
+  [picture: same URL in source (max-width:500px) and img, resize to narrow]
+    expected: FAIL
 
diff --git a/tests/wpt/metadata/html/semantics/embedded-content/the-img-element/non-active-document.html.ini b/tests/wpt/metadata/html/semantics/embedded-content/the-img-element/non-active-document.html.ini
deleted file mode 100644
index 8cc42056d34..00000000000
--- a/tests/wpt/metadata/html/semantics/embedded-content/the-img-element/non-active-document.html.ini
+++ /dev/null
@@ -1,10 +0,0 @@
-[non-active-document.html]
-  [DOMParser]
-    expected: FAIL
-
-  [createHTMLDocument]
-    expected: FAIL
-
-  [<template>]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/html/semantics/interactive-elements/the-details-element/toggleEvent.html.ini b/tests/wpt/metadata/html/semantics/interactive-elements/the-details-element/toggleEvent.html.ini
deleted file mode 100644
index 9e522297c94..00000000000
--- a/tests/wpt/metadata/html/semantics/interactive-elements/the-details-element/toggleEvent.html.ini
+++ /dev/null
@@ -1,7 +0,0 @@
-[toggleEvent.html]
-  [Calling open twice on 'details' fires only one toggle event]
-    expected: FAIL
-
-  [Setting open=true to opened 'details' element should not fire a toggle event at the 'details' element]
-    expected: FAIL
-
diff --git a/tests/wpt/metadata/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/aborted-parser.window.js.ini b/tests/wpt/metadata/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/aborted-parser.window.js.ini
index c6d49957c4a..ce482a60da8 100644
--- a/tests/wpt/metadata/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/aborted-parser.window.js.ini
+++ b/tests/wpt/metadata/html/webappapis/dynamic-markup-insertion/opening-the-input-stream/aborted-parser.window.js.ini
@@ -2,3 +2,6 @@
   [document.open() after parser is aborted]
     expected: FAIL
 
+  [async document.open() after parser is aborted]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/quirks/unitless-length/quirks.html.ini b/tests/wpt/metadata/quirks/unitless-length/quirks.html.ini
new file mode 100644
index 00000000000..2ed601c6ff4
--- /dev/null
+++ b/tests/wpt/metadata/quirks/unitless-length/quirks.html.ini
@@ -0,0 +1,283 @@
+[quirks.html]
+  [top: -\\31 .5]
+    expected: FAIL
+
+  [bottom: -1A]
+    expected: FAIL
+
+  [bottom: -1a]
+    expected: FAIL
+
+  [top: @1]
+    expected: FAIL
+
+  [top: "1a"]
+    expected: FAIL
+
+  [top: @a]
+    expected: FAIL
+
+  [bottom: "1"]
+    expected: FAIL
+
+  [bottom: -/**/1]
+    expected: FAIL
+
+  [top: +/**/1]
+    expected: FAIL
+
+  [bottom: @1a]
+    expected: FAIL
+
+  [top: 1\\31 ]
+    expected: FAIL
+
+  [top: url('1')]
+    expected: FAIL
+
+  [bottom: -\\31 ]
+    expected: FAIL
+
+  [top: calc(1)]
+    expected: FAIL
+
+  [top: \\31 ]
+    expected: FAIL
+
+  [bottom: +1\\31 ]
+    expected: FAIL
+
+  [bottom: 1\\31 .5]
+    expected: FAIL
+
+  [bottom: #0001]
+    expected: FAIL
+
+  [top: calc(2 * 2px)]
+    expected: FAIL
+
+  [bottom: 1a]
+    expected: FAIL
+
+  [bottom: A]
+    expected: FAIL
+
+  [bottom: #01]
+    expected: FAIL
+
+  [top: +\\31 .5]
+    expected: FAIL
+
+  [bottom: #1]
+    expected: FAIL
+
+  [top: -/**/1]
+    expected: FAIL
+
+  [bottom: +\\31 .5]
+    expected: FAIL
+
+  [bottom: \\31 ]
+    expected: FAIL
+
+  [bottom: calc(1)]
+    expected: FAIL
+
+  [top: #001]
+    expected: FAIL
+
+  [top: +\\31 ]
+    expected: FAIL
+
+  [bottom: +\\31 ]
+    expected: FAIL
+
+  [top: +1.5]
+    expected: FAIL
+
+  [top: +1\\31 ]
+    expected: FAIL
+
+  [bottom: @a]
+    expected: FAIL
+
+  [bottom: @1]
+    expected: FAIL
+
+  [top: #1]
+    expected: FAIL
+
+  [top: 1a]
+    expected: FAIL
+
+  [bottom: +1a]
+    expected: FAIL
+
+  [bottom: +1A]
+    expected: FAIL
+
+  [bottom: "a"]
+    expected: FAIL
+
+  [top: #00001]
+    expected: FAIL
+
+  [bottom: -1\\31 .5]
+    expected: FAIL
+
+  [top: "1"]
+    expected: FAIL
+
+  [bottom: 1.5]
+    expected: FAIL
+
+  [bottom: -\\31 .5]
+    expected: FAIL
+
+  [bottom: url('1')]
+    expected: FAIL
+
+  [bottom: -1.5]
+    expected: FAIL
+
+  [top: \\31 .5]
+    expected: FAIL
+
+  [bottom: "1a"]
+    expected: FAIL
+
+  [bottom: calc(2 * 2px)]
+    expected: FAIL
+
+  [bottom: +1\\31 .5]
+    expected: FAIL
+
+  [bottom: 1\\31 ]
+    expected: FAIL
+
+  [bottom: +/**/1]
+    expected: FAIL
+
+  [bottom: #00001]
+    expected: FAIL
+
+  [top: url(1)]
+    expected: FAIL
+
+  [bottom: #001]
+    expected: FAIL
+
+  [top: +1\\31 .5]
+    expected: FAIL
+
+  [top: -1a]
+    expected: FAIL
+
+  [top: -1A]
+    expected: FAIL
+
+  [bottom: url(1)]
+    expected: FAIL
+
+  [top: a]
+    expected: FAIL
+
+  [top: A]
+    expected: FAIL
+
+  [top: #000001]
+    expected: FAIL
+
+  [top: 1]
+    expected: FAIL
+
+  [top: 1\\31 .5]
+    expected: FAIL
+
+  [bottom: a]
+    expected: FAIL
+
+  [bottom: 1]
+    expected: FAIL
+
+  [bottom: +1]
+    expected: FAIL
+
+  [bottom: #000001]
+    expected: FAIL
+
+  [bottom: +a]
+    expected: FAIL
+
+  [bottom: +A]
+    expected: FAIL
+
+  [top: 1.5]
+    expected: FAIL
+
+  [top: +A]
+    expected: FAIL
+
+  [top: +a]
+    expected: FAIL
+
+  [top: +1]
+    expected: FAIL
+
+  [top: -1.5]
+    expected: FAIL
+
+  [top: -1\\31 .5]
+    expected: FAIL
+
+  [top: +1a]
+    expected: FAIL
+
+  [top: +1A]
+    expected: FAIL
+
+  [top: @1a]
+    expected: FAIL
+
+  [bottom: \\31 .5]
+    expected: FAIL
+
+  [top: "a"]
+    expected: FAIL
+
+  [top: #01]
+    expected: FAIL
+
+  [bottom: +1.5]
+    expected: FAIL
+
+  [bottom: -A]
+    expected: FAIL
+
+  [bottom: -a]
+    expected: FAIL
+
+  [bottom: -1\\31 ]
+    expected: FAIL
+
+  [top: #0001]
+    expected: FAIL
+
+  [bottom: -1]
+    expected: FAIL
+
+  [top: -\\31 ]
+    expected: FAIL
+
+  [top: -A]
+    expected: FAIL
+
+  [top: -a]
+    expected: FAIL
+
+  [top: -1]
+    expected: FAIL
+
+  [top: -1\\31 ]
+    expected: FAIL
+
diff --git a/tests/wpt/metadata/workers/semantics/multiple-workers/005.html.ini b/tests/wpt/metadata/workers/semantics/multiple-workers/005.html.ini
index f584fce5df1..268949ced5c 100644
--- a/tests/wpt/metadata/workers/semantics/multiple-workers/005.html.ini
+++ b/tests/wpt/metadata/workers/semantics/multiple-workers/005.html.ini
@@ -1,5 +1,4 @@
 [005.html]
-  expected: ERROR
   [dedicated worker in shared worker in dedicated worker]
     expected: FAIL
 
diff --git a/tests/wpt/web-platform-tests/infrastructure/testdriver/file_upload.py b/tests/wpt/web-platform-tests/infrastructure/testdriver/file_upload.py
new file mode 100644
index 00000000000..32633679a9f
--- /dev/null
+++ b/tests/wpt/web-platform-tests/infrastructure/testdriver/file_upload.py
@@ -0,0 +1,2 @@
+def main(request, response):
+    return "PASS" if request.POST["file_input"].file.read() == b"File to upload\n" else "FAIL"
diff --git a/tests/wpt/web-platform-tests/infrastructure/testdriver/file_upload.sub.html b/tests/wpt/web-platform-tests/infrastructure/testdriver/file_upload.sub.html
new file mode 100644
index 00000000000..29c42b49f17
--- /dev/null
+++ b/tests/wpt/web-platform-tests/infrastructure/testdriver/file_upload.sub.html
@@ -0,0 +1,26 @@
+<!doctype html>
+<meta charset=utf8>
+<title>File upload using testdriver</title>
+<script src="/resources/testharness.js"></script>
+<script src="/resources/testharnessreport.js"></script>
+<script src="/resources/testdriver.js"></script>
+<script src="/resources/testdriver-vendor.js"></script>
+<form id="form">
+  <input id="file_input" name="file_input" type="file">
+</form>
+<script>
+let form = document.getElementById("form");
+let input = document.getElementById("file_input");
+test_driver
+  .send_keys(input, "{{fs_path(file_upload_data.txt)}}")
+  .then(() =>
+    fetch("file_upload.py",
+      {method: "POST",
+       body: new FormData(form)}))
+   .then(response => response.text())
+   .then(data => {
+     assert_equals(data, "PASS");
+     done();
+   })
+   .catch(() => assert_unreached("File upload failed"));
+</script>
diff --git a/tests/wpt/web-platform-tests/infrastructure/testdriver/file_upload_data.txt b/tests/wpt/web-platform-tests/infrastructure/testdriver/file_upload_data.txt
new file mode 100644
index 00000000000..097d2a3a3f3
--- /dev/null
+++ b/tests/wpt/web-platform-tests/infrastructure/testdriver/file_upload_data.txt
@@ -0,0 +1 @@
+File to upload
diff --git a/tests/wpt/web-platform-tests/interfaces/webxr.idl b/tests/wpt/web-platform-tests/interfaces/webxr.idl
index 7f7b43c222b..27ee27493aa 100644
--- a/tests/wpt/web-platform-tests/interfaces/webxr.idl
+++ b/tests/wpt/web-platform-tests/interfaces/webxr.idl
@@ -17,17 +17,6 @@ partial interface Navigator {
   [SameObject] readonly attribute XR xr;
 };
 
-enum XRSessionMode {
-  "inline",
-  "immersive-vr",
-  "immersive-ar"
-};
-
-dictionary XRSessionCreationOptions {
-  XRSessionMode mode = "inline";
-  XRPresentationContext outputContext;
-};
-
 enum XREnvironmentBlendMode {
   "opaque",
   "additive",
@@ -64,6 +53,17 @@ enum XREnvironmentBlendMode {
   attribute EventHandler onselectend;
 };
 
+enum XRSessionMode {
+  "inline",
+  "immersive-vr",
+  "immersive-ar"
+};
+
+dictionary XRSessionCreationOptions {
+  XRSessionMode mode = "inline";
+  XRPresentationContext outputContext;
+};
+
 callback XRFrameRequestCallback = void (DOMHighResTimeStamp time, XRFrame frame);
 
 [SecureContext, Exposed=Window] interface XRFrame {
diff --git a/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/firefox.py b/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/firefox.py
index 59f06699b58..26d744749e5 100644
--- a/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/firefox.py
+++ b/tests/wpt/web-platform-tests/tools/wptrunner/wptrunner/browsers/firefox.py
@@ -243,7 +243,7 @@ class FirefoxBrowser(Browser):
         self.profile.set_preferences({
             "marionette.port": self.marionette_port,
             "network.dns.localDomains": ",".join(self.config.domains_set),
-
+            "dom.file.createInChild": True,
             # TODO: Remove preferences once Firefox 64 is stable (Bug 905404)
             "network.proxy.type": 0,
             "places.history.enabled": False,
diff --git a/tests/wpt/web-platform-tests/tools/wptserve/tests/functional/docroot/subdir/sub_path.sub.txt b/tests/wpt/web-platform-tests/tools/wptserve/tests/functional/docroot/subdir/sub_path.sub.txt
new file mode 100644
index 00000000000..44027f2855e
--- /dev/null
+++ b/tests/wpt/web-platform-tests/tools/wptserve/tests/functional/docroot/subdir/sub_path.sub.txt
@@ -0,0 +1,3 @@
+{{fs_path(sub_path.sub.txt)}}
+{{fs_path(../sub_path.sub.txt)}}
+{{fs_path(/sub_path.sub.txt)}}
diff --git a/tests/wpt/web-platform-tests/tools/wptserve/tests/functional/test_pipes.py b/tests/wpt/web-platform-tests/tools/wptserve/tests/functional/test_pipes.py
index 693cb82e241..2ba6f744b22 100644
--- a/tests/wpt/web-platform-tests/tools/wptserve/tests/functional/test_pipes.py
+++ b/tests/wpt/web-platform-tests/tools/wptserve/tests/functional/test_pipes.py
@@ -117,6 +117,15 @@ server: http://localhost:{0}""".format(self.server.port).encode("ascii")
         expected = b"localhost %d A %d B localhost C" % (port, port)
         self.assertEqual(resp.read().rstrip(), expected)
 
+    def test_sub_fs_path(self):
+        resp = self.request("/subdir/sub_path.sub.txt")
+        root = os.path.abspath(doc_root)
+        expected = """%(root)s%(sep)ssubdir%(sep)ssub_path.sub.txt
+%(root)s%(sep)ssub_path.sub.txt
+%(root)s%(sep)ssub_path.sub.txt
+""" % {"root": root, "sep": os.path.sep}
+        self.assertEqual(resp.read(), expected.encode("utf8"))
+
 class TestTrickle(TestUsingServer):
     def test_trickle(self):
         #Actually testing that the response trickles in is not that easy
diff --git a/tests/wpt/web-platform-tests/tools/wptserve/wptserve/pipes.py b/tests/wpt/web-platform-tests/tools/wptserve/wptserve/pipes.py
index bb24cd31006..92b284c93e3 100644
--- a/tests/wpt/web-platform-tests/tools/wptserve/wptserve/pipes.py
+++ b/tests/wpt/web-platform-tests/tools/wptserve/wptserve/pipes.py
@@ -354,6 +354,8 @@ def sub(request, response, escape_type="html"):
       sha224, sha256, sha384, and sha512. For example:
 
         {{file_hash(md5, dom/interfaces.html)}}
+    fs_path(filepath)
+      The absolute path to a file inside the wpt document root
 
     So for example in a setup running on localhost with a www
     subdomain and a http server on ports 80 and 81::
@@ -414,6 +416,21 @@ class SubFunctions(object):
 
         return base64.b64encode(hash_obj.digest()).strip()
 
+    @staticmethod
+    def fs_path(request, path):
+        if not path.startswith("/"):
+            subdir = request.request_path[len(request.url_base):]
+            if "/" in subdir:
+                subdir = subdir.rsplit("/", 1)[0]
+            root_rel_path = subdir + "/" + path
+        else:
+            root_rel_path = path[1:]
+        root_rel_path = root_rel_path.replace("/", os.path.sep)
+        absolute_path = os.path.abspath(os.path.join(request.doc_root, root_rel_path))
+        if ".." in os.path.relpath(absolute_path, request.doc_root):
+            raise ValueError("Path outside wpt root")
+        return absolute_path
+
 def template(request, content, escape_type="html"):
     #TODO: There basically isn't any error handling here
     tokenizer = ReplacementTokenizer()