1 files changed, 15 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/regexp/bug1640473.js b/js/src/jit-test/tests/regexp/bug1640473.js
new file mode 100644
index 0000000000..c4440bd8d6
--- /dev/null
+++ b/js/src/jit-test/tests/regexp/bug1640473.js
@@ -0,0 +1,15 @@
+var s = "";
+var input = "";
+for (var i = 0; i < 500; ++i) {
+    s += "(?<a" + i + ">a)";
+    s += "(?<b" + i + ">b)?";
+    input += "a";
+}
+
+var r = RegExp(s);
+var e = r.exec(input);
+
+for (var i = 0; i < 500; i++) {
+    assertEq(e.groups["a" + i], "a");
+    assertEq(e.groups["b" + i], undefined);
+}