1 files changed, 14 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/auto-regress/bug1689880-1.js b/js/src/jit-test/tests/auto-regress/bug1689880-1.js
new file mode 100644
index 0000000000..e2da308010
--- /dev/null
+++ b/js/src/jit-test/tests/auto-regress/bug1689880-1.js
@@ -0,0 +1,14 @@
+// |jit-test| error: ReferenceError
+
+// We elide the uninitialised lexical check for the second access to |x|,
+// because we statically know that the first access will throw an error.
+// `!x` is compiled straight from bytecode without going through any ICs, so
+// already on first (eager) compilation we may be Warp compiling.
+
+function testNot(x = (x, !x)) {
+    function inner() {
+        // Close over |x|.
+        x;
+    }
+}
+testNot();