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<!DOCTYPE html>
<html class="reftest-wait">
<head>
<meta charset="utf-8" />
<script src="/tests/SimpleTest/SimpleTest.js"></script>
<link rel="stylesheet" href="/tests/SimpleTest/test.css" />
</head>
<body>
<script>
// Ensure that, when WebGPU generates an error message that is later
// truncated by `wgpu_bindings::error::ErrorBuffer::init`, that
// truncation always produces valid UTF-8, even when the error contains
// multi-byte encodings.
async function truncate_error_messages() {
// The specific error we'll try to provoke is submitting a command
// buffer to the wrong device's queue.
const adapter = await navigator.gpu.requestAdapter();
const device1 = await adapter.requestDevice();
const device2 = await adapter.requestDevice();
// Try a range of label lengths (578±200, where 578 is the length that
// tickles the original bug), searching for one that, when combined with
// the error message and then truncated at whatever error message byte
// length limit Firefox is imposing, will produce invalid UTF-8.
//
// Use a label containing n space characters followed by a crab emoji,
// U+1F980, which requires four bytes to encode in UTF-8. Since this has
// a four-byte encoding at the end, we only need to try every third
// length to ensure we will always try a truncation point in the midst
// of that encoding.
for (let len = 378; len < 778; len += 3) {
const label = ' '.repeat(len) + '\uD83E\uDD80';
const encoder = device1.createCommandEncoder({ label });
const command_buffer = encoder.finish();
// We don't want an error scope around this, because what makes
// Firefox notice the bad UTF-8 is attempting to log the uncaught
// WebGPU error as a warning.
device2.queue.submit([command_buffer]);
}
}
truncate_error_messages()
.catch(e => {
console.log(e);
})
.finally(() => {
// End the crashtest.
document.documentElement.removeAttribute("class");
});
</script>
</body>
</html>
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