1 files changed, 16 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/gc/str-atom-dedupe.js b/js/src/jit-test/tests/gc/str-atom-dedupe.js
new file mode 100644
index 0000000000..587f879db5
--- /dev/null
+++ b/js/src/jit-test/tests/gc/str-atom-dedupe.js
@@ -0,0 +1,16 @@
+// Create Latin1 string + atom.
+var latin1S = "foo".repeat(50);
+var obj = {};
+obj[latin1S] = 3;
+assertEq(obj[latin1S], 3);
+
+// Create a TwoByte version, ensure it's in the StringToAtomCache.
+var twoByteS = newString(latin1S, {twoByte: true});
+assertEq(obj[twoByteS], 3);
+
+// Create a dependent TwoByte string.
+var depTwoByteS = twoByteS.slice(1);
+
+// Deduplication shouldn't get confused about Latin1 atom vs TwoByte strings.
+minorgc();
+assertEq(obj["f" + depTwoByteS], 3);