1 files changed, 36 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/debug/class-derived-default-constructor-1.js b/js/src/jit-test/tests/debug/class-derived-default-constructor-1.js
new file mode 100644
index 0000000000..baabc338b6
--- /dev/null
+++ b/js/src/jit-test/tests/debug/class-derived-default-constructor-1.js
@@ -0,0 +1,36 @@
+const g = newGlobal({newCompartment: true});
+g.eval(`
+  class Base {}
+  class Derived extends Base {}
+  this.Derived = Derived;
+`);
+
+const dbg = new Debugger(g);
+const gw = dbg.addDebuggee(g);
+
+let calleeCount = 0;
+
+dbg.onEnterFrame = frame => {
+  // Ignore any other callees.
+  if (frame.callee !== gw.makeDebuggeeValue(g.Derived)) {
+    return;
+  }
+
+  calleeCount++;
+
+  const names = frame.environment.names();
+
+  // Set all variables to |null|. This mustn't affect the implicit rest-argument
+  // of the default derived class constructor, otherwise we'll crash when
+  // passing the rest-argument to the super spread-call.
+  frame.onStep = () => {
+    names.forEach(name => {
+      frame.environment.setVariable(name, null);
+    });
+  };
+};
+
+new g.Derived();
+
+// |Derived| should be called at most once.
+assertEq(calleeCount, 1);