fonts: Fix loading local web font by TimvdLippe · Pull Request #41714 · servo/servo

TimvdLippe · 2026-01-06T17:15:46Z

When you open a local file that attempts to load a web font, previously it would trigger an assertion on the origin of the request being unequal to the
client.

We would set both the origin of the request as well as the client explicitly for fonts. Instead,
request.populate_request_from_client is supposed to initialize that.

Therefore, remove the explicit origin and instead rely on the client origin.

Fixes #41713
Testing: This only affects file URLs which are not well covered by automated tests

github-actions · 2026-01-06T17:18:06Z

🔨 Triggering try run (#20756079881) for Linux (WPT)

github-actions · 2026-01-06T17:59:42Z

Test results for linux-wpt from try job (#20756079881):

Flaky unexpected result (34)

PASS [expected FAIL] /_mozilla/css/linear_gradients_reverse_a.html

OK /_mozilla/css/offset_properties_inline.html (#40543)

FAIL [expected PASS] subtest: offsetTop

assert_equals: offsetTop of #inline-1 should be 0. expected 0 but got -1

FAIL [expected PASS] subtest: offsetLeft

assert_equals: offsetLeft of #inline-2 should be 40. expected 40 but got 25

OK /_mozilla/webxr/create_session.https.html
- FAIL [expected PASS] subtest: create_session
```
can't access property "simulateDeviceConnection", navigator.xr.test is undefined
```

OK /_mozilla/webxr/obtain_frame.https.html

FAIL [expected PASS] subtest: obtain_frame

promise_test: Unhandled rejection with value: object "TypeError: can't access property "simulateDeviceConnection", navigator.xr.test is undefined"

CRASH [expected OK] /_webgl/conformance/glsl/implicit/subtract_int_vec2.vert.html

OK /_webgl/conformance/textures/misc/texture-upload-size.html (#21770)

FAIL [expected PASS] subtest: WebGL test #77

assert_true: Texture was smaller than the expected size 2x2 expected true got false

FAIL [expected PASS] subtest: WebGL test #79

assert_true: getError expected: INVALID_VALUE. Was NO_ERROR : when calling texSubImage2D with the same texture upload with offset 1, 1 expected true got false

FAIL [expected PASS] subtest: WebGL test #81

assert_true: Texture was smaller than the expected size 2x2 expected true got false

FAIL [expected PASS] subtest: WebGL test #83

assert_true: getError expected: INVALID_VALUE. Was NO_ERROR : when calling texSubImage2D with the same texture upload with offset 1, 1 expected true got false

OK /content-security-policy/frame-ancestors/frame-ancestors-path-ignored.window.html (#36468)
- PASS [expected FAIL] subtest: A 'frame-ancestors' CSP directive with a URL that includes a path should be ignored.
TIMEOUT [expected OK] /credential-management/credentialscontainer-frame-basics.https.html (#39430)
- TIMEOUT [expected FAIL] subtest: navigator.credentials should be undefined in documents generated from data: URLs.
```
Test timed out
```
FAIL [expected PASS] /css/css-backgrounds/border-image-repeat-space-9.html
OK /css/css-fonts/generic-family-keywords-001.html (#37467)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted generic(fangsong)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted generic(khmer-mul)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted generic(nastaliq)
TIMEOUT [expected PASS] /css/css-text/text-align/text-align-match-parent-001.html
OK /custom-elements/form-associated/ElementInternals-setFormValue.html (#29174)
- PASS [expected FAIL] subtest: Single value - Non-empty name exists
OK /html/browsers/browsing-the-web/navigating-across-documents/initial-empty-document/load-pageshow-events-window-open.html (#28691)
- PASS [expected FAIL] subtest: load event does not fire on window.open('about:blank')
OK /html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin-fragment.html (#20768)
- FAIL [expected PASS] subtest: Tests that a fragment navigation in the unload handler will not block the initial navigation
```
assert_equals: expected "" but got "#fragment"
```
OK /html/browsers/browsing-the-web/navigating-across-documents/navigation-unload-same-origin.window.html (#29049)
- PASS [expected FAIL] subtest: Same-origin navigation started from unload handler must be ignored
OK /html/browsers/browsing-the-web/navigating-across-documents/replace-before-load/a-click.html (#28697)
- PASS [expected FAIL] subtest: aElement.click() before the load event must NOT replace
TIMEOUT [expected OK] /html/interaction/focus/the-autofocus-attribute/document-with-fragment-top.html (#28259)
- TIMEOUT [expected FAIL] subtest: Autofocus elements in top-level browsing context's documents with "top" fragments should work.
```
Test timed out
```
OK /html/semantics/embedded-content/the-iframe-element/iframe-loading-lazy-nav-location-replace-set-src.html (#32697)
- PASS [expected FAIL] subtest: Navigating iframe loading='lazy' and then setting src: location.replace
TIMEOUT [expected OK] /html/semantics/embedded-content/the-iframe-element/iframe_sandbox_navigate_other_frame_popup.sub.html (#39702)
- TIMEOUT [expected FAIL] subtest: Sandboxed iframe can not navigate other frame's popup
```
Test timed out
```
OK /html/semantics/forms/form-submission-0/jsurl-form-submit.tentative.html (#36489)
- PASS [expected FAIL] subtest: Verifies that form submissions scheduled inside javascript: urls take precedence over the javascript: url's return value.
OK /html/semantics/forms/form-submission-0/text-plain.window.html (#28687)
- FAIL [expected PASS] subtest: text/plain: Basic test (formdata event)
```
assert_equals: expected "basic=test\r\n" but got ""
```
- FAIL [expected PASS] subtest: text/plain: Basic File test (normal form)
```
assert_equals: expected "basic=file-test.txt\r\n" but got ""
```
- PASS [expected FAIL] subtest: text/plain: backslash in filename (formdata event)
OK /html/semantics/forms/form-submission-0/urlencoded2.window.html (#28687)
- FAIL [expected PASS] subtest: application/x-www-form-urlencoded: Basic test (formdata event)
```
assert_equals: expected "basic=test" but got ""
```
- PASS [expected FAIL] subtest: application/x-www-form-urlencoded: 0x00 in value (formdata event)
- PASS [expected FAIL] subtest: application/x-www-form-urlencoded: single quote in filename (formdata event)
- PASS [expected FAIL] subtest: application/x-www-form-urlencoded: characters not in encoding in name and value (normal form)
CRASH [expected TIMEOUT] /html/semantics/forms/the-select-element/customizable-select/select-appearance-picker-select-border.html
OK /html/semantics/scripting-1/the-script-element/module/dynamic-import/blob-url.any.html (#33948)
- FAIL [expected PASS] subtest: Revoking a blob URL immediately after calling import will not fail
```
promise_test: Unhandled rejection with value: object "TypeError: Dynamic import failed"
```
OK /mixed-content/tentative/autoupgrades/mixed-content-cors.https.sub.html (#41123)
- FAIL [expected PASS] subtest: Cross-Origin video should get upgraded even if CORS is set
```
assert_equals: Length. Other host expected 1 but got Infinity
```
OK /preload/link-header-preload-delay-onload.html (#39622)
- FAIL [expected PASS] subtest: Makes sure that Link headers preload resources and block window.onload after resource discovery
```
assert_true: expected true got false
```
CRASH [expected OK] /resource-timing/render-blocking-status-link.html (#41664)
OK /touch-events/single-tap-when-touchend-listener-use-sync-xhr.html (#41175)
- PASS [expected FAIL] subtest: Click event should be fired when touchend opens synchronous XHR
CRASH [expected OK] /trusted-types/eval-function-constructor.html
TIMEOUT /trusted-types/trusted-types-navigation.html?06-10 (#37920)
- PASS [expected FAIL] subtest: Navigate a frame via anchor with javascript:-urls in report-only mode.
OK [expected TIMEOUT] /trusted-types/trusted-types-navigation.html?26-30 (#38807)
- PASS [expected TIMEOUT] subtest: Navigate a window via form-submission with javascript:-urls in report-only mode.
- PASS [expected NOTRUN] subtest: Navigate a window via form-submission with javascript:-urls w/ default policy in report-only mode.
- PASS [expected NOTRUN] subtest: Navigate a frame via form-submission with javascript:-urls in enforcing mode.
- PASS [expected NOTRUN] subtest: Navigate a frame via form-submission with javascript:-urls w/ default policy in enforcing mode.
CRASH [expected OK] /wasm/webapi/esm-integration/wasm-to-wasm-link-error.tentative.html
CRASH [expected OK] /webaudio/the-audio-api/processing-model/feedback-delay-time.html
OK [expected TIMEOUT] /webstorage/localstorage-about-blank-3P-iframe-opens-3P-window.partitioned.html (#29053)
- PASS [expected TIMEOUT] subtest: StorageKey: test 3P about:blank window opened from a 3P iframe

Stable unexpected results that are known to be intermittent (29)

OK /IndexedDB/idbcursor-continuePrimaryKey-exceptions.any.html (#39277)

FAIL [expected PASS] subtest: IDBCursor continuePrimaryKey() on object store cursor

assert_throws_dom: continuePrimaryKey() should throw if source is not an index function "function() {
        cursor.continuePrimaryKey(2, 2);
      }" threw object "TypeError: cursor.continuePrimaryKey is not a function" that is not a DOMException InvalidAccessError: property "code" is equal to undefined, expected 15

OK /IndexedDB/idbcursor-continuePrimaryKey-exceptions.any.worker.html (#39277)

FAIL [expected PASS] subtest: IDBCursor continuePrimaryKey() on object store cursor

assert_throws_dom: continuePrimaryKey() should throw if source is not an index function "function() {
        cursor.continuePrimaryKey(2, 2);
      }" threw object "TypeError: cursor.continuePrimaryKey is not a function" that is not a DOMException InvalidAccessError: property "code" is equal to undefined, expected 15

OK /IndexedDB/idbobjectstore_getAll.any.html (#39276)
- PASS [expected FAIL] subtest: Get all values with transaction.commit()
OK /IndexedDB/idbobjectstore_getAll.any.worker.html (#39400)
- PASS [expected FAIL] subtest: Get all values with transaction.commit()
OK /IndexedDB/idbrequest-onupgradeneeded.any.html (#38895)
- PASS [expected FAIL] subtest: transaction oncomplete ordering relative to open request onsuccess
OK /IndexedDB/idbrequest-onupgradeneeded.any.worker.html (#38971)
- PASS [expected FAIL] subtest: transaction oncomplete ordering relative to open request onsuccess

OK /IndexedDB/key-conversion-exceptions.any.html (#39305)

FAIL [expected PASS] subtest: IDBCursor continue() method with throwing/invalid keys

assert_throws_exactly: key conversion with throwing getter should rethrow function "() =&gt; {
      receiver[method](key);
    }" threw object "TypeError: receiver[method] is not a function" but we expected it to throw object "getter: throwing from getter"

FAIL [expected PASS] subtest: IDBCursor update() method with throwing/invalid keys

assert_throws_exactly: throwing getter should rethrow during clone function "() =&gt; {
      cursor.update(value);
    }" threw object "TypeError: cursor.update is not a function" but we expected it to throw object "getter: throwing from getter"

OK /IndexedDB/key-conversion-exceptions.any.worker.html (#39284)

FAIL [expected PASS] subtest: IDBCursor continue() method with throwing/invalid keys

assert_throws_exactly: key conversion with throwing getter should rethrow function "() =&gt; {
      receiver[method](key);
    }" threw object "TypeError: receiver[method] is not a function" but we expected it to throw object "getter: throwing from getter"

FAIL [expected PASS] subtest: IDBCursor update() method with throwing/invalid keys

assert_throws_exactly: throwing getter should rethrow during clone function "() =&gt; {
      cursor.update(value);
    }" threw object "TypeError: cursor.update is not a function" but we expected it to throw object "getter: throwing from getter"

FAIL [expected PASS] /_mozilla/mozilla/sslfail.html (#10760)
TIMEOUT [expected OK] /_mozilla/mozilla/window_resize_event.html (#36741)
- TIMEOUT [expected PASS] subtest: Popup onresize event fires after resizeTo
```
Test timed out
```
CRASH [expected PASS] /_mozilla/shadow-dom/move-element-with-ua-shadow-tree-crash.html (#39473)
TIMEOUT /content-security-policy/inheritance/location-reload.html (#38983)
- FAIL [expected PASS] subtest: location.reload() of empty iframe.
```
assert_equals: Image should be blocked by CSP after reload. expected "img blocked" but got "img loaded"
```
OK /css/css-fonts/generic-family-keywords-003.html (#38994)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted system-ui (drawing text in a canvas)
- PASS [expected FAIL] subtest: @font-face matching for quoted and unquoted ui-rounded (drawing text in a canvas)
ERROR [expected OK] /fetch/fetch-later/quota/same-origin-iframe/multiple-iframes.https.window.html (#35176)
OK /fetch/metadata/generated/css-font-face.https.sub.tentative.html (#32732)
- PASS [expected FAIL] subtest: sec-fetch-user
OK /fetch/metadata/generated/css-font-face.sub.tentative.html (#34624)
- PASS [expected FAIL] subtest: sec-fetch-storage-access - Not sent to non-trustworthy same-origin destination
- PASS [expected FAIL] subtest: sec-fetch-storage-access - Not sent to non-trustworthy same-site destination
ERROR [expected OK] /focus/focus-event-after-switching-iframes.sub.html (#40368)
OK /html/browsers/history/the-history-interface/traverse_the_history_5.html (#21383)
- PASS [expected FAIL] subtest: Multiple history traversals, last would be aborted

OK [expected TIMEOUT] /html/interaction/focus/the-autofocus-attribute/supported-elements.html (#24145)

FAIL [expected NOTRUN] subtest: Host element with delegatesFocus should support autofocus

assert_equals: expected Element node &lt;div autofocus=""&gt;&lt;/div&gt; but got Element node &lt;body&gt;&lt;div autofocus=""&gt;&lt;/div&gt;&lt;/body&gt;

FAIL [expected NOTRUN] subtest: Host element with delegatesFocus including no focusable descendants should be skipped

assert_equals: expected Element node &lt;input autofocus=""&gt;&lt;/input&gt; but got Element node &lt;body&gt;&lt;/body&gt;

FAIL [expected NOTRUN] subtest: Area element should support autofocus

assert_equals: expected Element node &lt;area autofocus="" href="/common/blank.html"&gt;&lt;/area&gt; but got Element node &lt;body&gt;
&lt;img src="/media/poster.png" usemap="#map"&gt;
&lt;map n...

TIMEOUT [expected ERROR] /html/semantics/links/links-created-by-a-and-area-elements/target_blank_implicit_noopener_base.html (#40347)

OK /html/semantics/scripting-1/the-script-element/execution-timing/077.html (#22139)

FAIL [expected PASS] subtest: adding several types of scripts through the DOM and removing some of them confuses scheduler

assert_array_equals: expected property 1 to be "Script #1 ran" but got "Script #3 ran" (expected array ["Script #2 ran", "Script #1 ran", "Script #3 ran", "Script #4 ran"] got ["Script #2 ran", "Script #3 ran", "Script #4 ran", "Script #1 ran"])

OK /html/webappapis/user-prompts/print-during-unload.html (#35944)
- PASS [expected FAIL] subtest: print() during unload
FAIL [expected PASS] /png/apng/acTL-plays-one.html (#41218)
OK /preload/prefetch-document.html (#37210)
- PASS [expected FAIL] subtest: different-site document prefetch with 'as=document' should not be consumed
OK /preload/preload-error.sub.html (#37177)
- PASS [expected FAIL] subtest: 404 (image): main
- FAIL [expected PASS] subtest: 404 (style): main
```
assert_unreached: Should have rejected: undefined Reached unreachable code
```
- FAIL [expected PASS] subtest: 404 (script): main
```
assert_unreached: Should have rejected: undefined Reached unreachable code
```
- PASS [expected FAIL] subtest: CORS (fetch): main
TIMEOUT /resource-timing/test_resource_timing.html (#25720)
- PASS [expected FAIL] subtest: window.performance.getEntriesByName() and window.performance.getEntriesByNameType() return same data (xmlhttprequest)
TIMEOUT /resource-timing/test_resource_timing.https.html (#25216)
- PASS [expected FAIL] subtest: window.performance.getEntriesByName() and window.performance.getEntriesByNameType() return same data (xmlhttprequest)
TIMEOUT [expected OK] /trusted-types/trusted-types-navigation.html?01-05 (#38975)
- TIMEOUT [expected PASS] subtest: Navigate a window via anchor with javascript:-urls in report-only mode.
```
Test timed out
```
- NOTRUN [expected PASS] subtest: Navigate a window via anchor with javascript:-urls w/ default policy in report-only mode.
- NOTRUN [expected PASS] subtest: Navigate a frame via anchor with javascript:-urls in enforcing mode.
ERROR [expected OK] /webxr/render_state_update.https.html (#27535)

github-actions · 2026-01-06T17:59:50Z

✨ Try run (#20756079881) succeeded.

mrobinson

Thank you for addressing this so quickly. I do have a question about this fix:

mrobinson · 2026-01-06T17:57:49Z

tests/wpt/mozilla/tests/mozilla/loading-web-font-crash.html

+<!DOCTYPE html>
+<link rel="help" href="https://github.com/servo/servo/issues/41713">
+<style>
+@font-face {
+  font-family: "Amstelvar VF";
+  src: url("https://mdn.github.io/shared-assets/fonts/variable-fonts/AmstelvarAlpha-VF.woff2")
+}
+html {
+  font-family: "Amstelvar VF";
+  font-size: 4rem;
+}
+</style>
+
+Hello


I think you can just remove this test file completely:

Tests should not rely on remote resources.

I don't think it will trigger the bug as tests are run from a local web server and this issue is only about file:// URLs.

components/fonts/font_context.rs

mrobinson

Ah! I missed the conversation on #41713. This looks good, please remove the test before landing. I would just say something like "Testing: This only affects file URLs which are not well covered by automated tests."

When you open a local file that attempts to load a web font, previously it would trigger an assertion on the origin of the request being unequal to the client. We would set both the origin of the request as well as the client explicitly for fonts. Instead, `request.populate_request_from_client` is supposed to initialize that. Therefore, remove the explicit origin and instead rely on the client origin. Fixes servo#41713 Signed-off-by: Tim van der Lippe <[email protected]>

TimvdLippe requested a review from mrobinson January 6, 2026 17:15

TimvdLippe requested a review from nicoburns as a code owner January 6, 2026 17:15

servo-highfive added the S-awaiting-review There is new code that needs to be reviewed. label Jan 6, 2026

TimvdLippe added the T-linux-wpt Do a try run of the WPT label Jan 6, 2026

TimvdLippe mentioned this pull request Jan 6, 2026

Loading web fonts is broken from local files #41713

Closed

github-actions bot removed the T-linux-wpt Do a try run of the WPT label Jan 6, 2026

mrobinson reviewed Jan 6, 2026

View reviewed changes

mrobinson approved these changes Jan 6, 2026

View reviewed changes

servo-highfive removed the S-awaiting-review There is new code that needs to be reviewed. label Jan 6, 2026

TimvdLippe force-pushed the fix-local-font-loading branch from 1011ff7 to 7a8150f Compare January 7, 2026 13:05

servo-highfive added the S-awaiting-review There is new code that needs to be reviewed. label Jan 7, 2026

TimvdLippe enabled auto-merge January 7, 2026 13:06

TimvdLippe added this pull request to the merge queue Jan 7, 2026

servo-highfive added the S-awaiting-merge The PR is in the process of compiling and running tests on the automated CI. label Jan 7, 2026

Merged via the queue into servo:main with commit 69169b7 Jan 7, 2026
33 checks passed

TimvdLippe deleted the fix-local-font-loading branch January 7, 2026 13:59

servo-highfive removed the S-awaiting-merge The PR is in the process of compiling and running tests on the automated CI. label Jan 7, 2026

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fonts: Fix loading local web font#41714

fonts: Fix loading local web font#41714
TimvdLippe merged 1 commit intoservo:mainfrom
TimvdLippe:fix-local-font-loading

TimvdLippe commented Jan 6, 2026 •

edited

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TimvdLippe commented Jan 6, 2026 •

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