src/third_party/mozjs-45/js/src/jit-test/tests/debug/bug-725733.js

// |jit-test|
// Adding a debuggee must leave its scripts in a safe state.

var g = newGlobal();
g.eval(
    "function f(x) { return {q: x}; }\n" +
    "var n = f('').q;\n");
var dbg = new Debugger(g);
g.eval("f(0)");