Loading web fonts is broken from local files #41713
Description
It seems that loading web fonts is broken from local files. When I run the following test case via ./mach run -r test.html I receive an assertion failure:
<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>
Helloassertion failed: request.origin == client.origin (thread tokio-runtime-5, at components/net/fetch/methods.rs:181)
0: <servoshell::backtrace::Print as core::fmt::Debug>::fmt
1: core::fmt::write
2: std::io::Write::write_fmt
3: servoshell::backtrace::print
4: servoshell::panic_hook::panic_hook
5: std::panicking::panic_with_hook
6: std::panicking::panic_handler::{{closure}}
7: std::sys::backtrace::__rust_end_short_backtrace
8: __rustc::rust_begin_unwind
9: core::panicking::panic_fmt
10: core::panicking::panic
11: net::fetch::methods::fetch::{{closure}}
12: <core::pin::Pin<P> as core::future::future::Future>::poll
13: tokio::runtime::task::core::Core<T,S>::poll
14: tokio::runtime::task::harness::Harness<T,S>::poll
15: tokio::runtime::scheduler::multi_thread::worker::Context::run_task
16: tokio::runtime::scheduler::multi_thread::worker::Context::run
17: tokio::runtime::context::scoped::Scoped<T>::set
18: tokio::runtime::context::runtime::enter_runtime
19: tokio::runtime::scheduler::multi_thread::worker::run
20: <tokio::runtime::blocking::task::BlockingTask<T> as core::future::future::Future>::poll
21: tokio::runtime::task::core::Core<T,S>::poll
22: tokio::runtime::task::harness::Harness<T,S>::poll
23: tokio::runtime::blocking::pool::Inner::run
24: std::sys::backtrace::__rust_begin_short_backtrace
25: core::ops::function::FnOnce::call_once{{vtable.shim}}
26: std::sys::thread::unix::Thread::new::thread_start
27: __pthread_cond_wait
[2026-01-06T15:47:42Z ERROR servoshell::panic_hook] assertion failed: request.origin == client.origin
Commenting out the assertion on line 181 of method.rs causes the font to load properly without issue. Is it possible that the assertion is wrong?
cc @TimvdLippe