1 files changed, 30 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/basic/globals-shared-shapes.js b/js/src/jit-test/tests/basic/globals-shared-shapes.js
new file mode 100644
index 000000000..f2f0013ce
--- /dev/null
+++ b/js/src/jit-test/tests/basic/globals-shared-shapes.js
@@ -0,0 +1,30 @@
+// Test that objects in different compartments can have the same shape.
+
+var g1 = newGlobal();
+var g2 = newGlobal({sameZoneAs: g1});
+
+g1.eval("x1 = {foo: 1}");
+g2.eval("x2 = {foo: 2}");
+assertEq(unwrappedObjectsHaveSameShape(g1.x1, g2.x2), true);
+
+g1.eval("x1 = [1]");
+g2.eval("x2 = [2]");
+assertEq(unwrappedObjectsHaveSameShape(g1.x1, g2.x2), true);
+
+g1.eval("x1 = function f(){}");
+g2.eval("x2 = function f(){}");
+assertEq(unwrappedObjectsHaveSameShape(g1.x1, g2.x2), true);
+
+g1.eval("x1 = /abc/;");
+g2.eval("x2 = /def/");
+assertEq(unwrappedObjectsHaveSameShape(g1.x1, g2.x2), true);
+
+// Now the same, but we change Array.prototype.__proto__.
+// The arrays should no longer get the same Shape, as their
+// proto chain is different.
+g1 = newGlobal();
+g2 = newGlobal({sameZoneAs: g1});
+g1.eval("x1 = [1];");
+g2.eval("Array.prototype.__proto__ = Math;");
+g2.eval("x2 = [2];");
+assertEq(unwrappedObjectsHaveSameShape(g1.x1, g2.x2), false);