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<th>Bug ID</th>
<td><a class="bz_bug_link
bz_status_NEW "
title="NEW - GetByID IC is using the wrong value for value.__proto__ when the value is the global object."
href="https://bugs.webkit.org/show_bug.cgi?id=165401">165401</a>
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<th>Summary</th>
<td>GetByID IC is using the wrong value for value.__proto__ when the value is the global object.
</td>
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<th>Classification</th>
<td>Unclassified
</td>
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<th>Product</th>
<td>WebKit
</td>
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<th>Version</th>
<td>WebKit Local Build
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<th>Hardware</th>
<td>Unspecified
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<th>OS</th>
<td>Unspecified
</td>
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<th>Status</th>
<td>NEW
</td>
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<th>Severity</th>
<td>Normal
</td>
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<th>Priority</th>
<td>P2
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<th>Component</th>
<td>JavaScriptCore
</td>
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<th>Assignee</th>
<td>webkit-unassigned@lists.webkit.org
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<th>Reporter</th>
<td>mark.lam@apple.com
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<p>
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<pre>Here's the test case:
function test(x) {
x.__proto__
}
for (var i = 0; i < 10000; i++)
test(this);
As soon as test is JIT compiled and the GetById IC gets optimized, we'll get an exception:
TypeError: Object.prototype.__proto__ called on null or undefined
This should never be the case because x (in the test above) is never null or undefined.</pre>
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