1 files changed, 14 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/regexp/lastIndex-negative.js b/js/src/jit-test/tests/regexp/lastIndex-negative.js
new file mode 100644
index 0000000000..536b3d2233
--- /dev/null
+++ b/js/src/jit-test/tests/regexp/lastIndex-negative.js
@@ -0,0 +1,14 @@
+// A negative lastIndex value must be treated as 0.
+function test() {
+    var re = /abc.+de/g;
+    for (var i = 0; i < 100; i++) {
+        re.lastIndex = (i > 60) ? -1 : 0;
+        assertEq(typeof re.exec("abcXdef"), "object");
+        assertEq(re.lastIndex, 6);
+
+        re.lastIndex = (i > 60) ? -1 : 0;
+        assertEq(re.test("abcXdef"), true);
+        assertEq(re.lastIndex, 6);
+    }
+}
+test();