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<!doctype html>
<meta charset=utf-8>
<title></title>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<script>
function parseBlob(blob) {
return new Promise(resolve => {
let xhr = new XMLHttpRequest();
xhr.open("GET", URL.createObjectURL(blob));
xhr.onload = () => {
resolve(xhr.responseXML);
}
xhr.send();
});
}
promise_test(async (t) => {
// Most browser engines, including Gecko, use 5000 as the limit, so test a
// range around that.
const cutoff = 5000;
let minDepth = cutoff - 100;
let maxDepth = cutoff + 100;
// Generate a string with elements nested maxDepth deep.
const openTag = "<x>";
const closeTag = "</x>";
let xml = openTag.repeat(maxDepth) + closeTag.repeat(maxDepth);
// Compute where we change from opening to closing tags.
const middle = maxDepth * openTag.length;
// Create a blob around the string.
let blob = new Blob([xml], { type: "application/xml" });
while (minDepth < maxDepth) {
// Try to parse a number of nested tags between minDepth and maxDepth.
let test = Math.ceil((minDepth + maxDepth) / 2);
// We need the number of opening and closing tags to be equal to the number
// that we calculated above.
let slice = blob.slice(middle - (test * openTag.length),
middle + (test * closeTag.length), blob.type);
let responseXML = await parseBlob(slice);
// Move either minDepth or maxDepth so that the actual limit is still in the
// range of [minDepth-maxDepth].
if (responseXML) {
// Depth is ok.
minDepth = test;
} else {
maxDepth = test - 1;
}
}
assert_equals(minDepth, maxDepth);
assert_equals(minDepth, cutoff);
},"Parsing XML fails when the nesting depth is 5000");
</script>
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