1 files changed, 24 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/sharedbuf/typedarray-from-sharedtypedarray-with-overridden-length.js b/js/src/jit-test/tests/sharedbuf/typedarray-from-sharedtypedarray-with-overridden-length.js
new file mode 100644
index 0000000000..100443495a
--- /dev/null
+++ b/js/src/jit-test/tests/sharedbuf/typedarray-from-sharedtypedarray-with-overridden-length.js
@@ -0,0 +1,24 @@
+// |jit-test| skip-if: !this.SharedArrayBuffer
+
+// This would hit an assertion in debug builds due to an incorrect
+// type guard in the code that copies data from STA to TA.
+
+// Original test case
+
+var sab = new SharedArrayBuffer(4);
+
+var x = new Int32Array(sab);
+x.__proto__ = (function(){});
+new Uint8Array(x);		// Would assert here
+
+// Supposedly equivalent test case, provoking the error directly
+
+var x = new Int32Array(sab);
+Object.defineProperty(x, "length", { value: 0 });
+new Uint8Array(x);		// Would assert here
+
+// Derived test case - would not tickle the bug, though.
+
+var x = new Int32Array(sab);
+Object.defineProperty(x, "length", { value: 1 << 20 });
+new Uint8Array(x);