1 files changed, 38 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/debug/optimized-out-02.js b/js/src/jit-test/tests/debug/optimized-out-02.js
new file mode 100644
index 0000000000..c7690cca7a
--- /dev/null
+++ b/js/src/jit-test/tests/debug/optimized-out-02.js
@@ -0,0 +1,38 @@
+// Test that prevUpToDate on frames are cleared.
+
+var g = newGlobal({newCompartment: true});
+var dbg = new Debugger(g);
+
+g.eval(`
+function outer(unaliasedArg) {
+  var unaliasedVar = unaliasedArg + 42;
+  var aliasedVar = unaliasedArg;
+
+  inner();
+  return unaliasedVar; // To prevent the JIT from optimizing out unaliasedVar.
+
+  function inner() {
+    aliasedVar++;
+  }
+}
+`);
+
+var log = "";
+for (var script of dbg.findScripts()) {
+  if (script.displayName === "inner") {
+    script.setBreakpoint(0, { hit: function(frame) {
+      // Force updateLiveScopes.
+      var outerEnv = frame.environment;
+
+      // Get the environment of outer's frame on the stack, so that we may
+      // recover unaliased bindings in the debug scope.
+      outerEnv = frame.older.environment;
+      log += outerEnv.getVariable('unaliasedArg'); // 42
+      log += outerEnv.getVariable('unaliasedVar'); // 84
+      log += outerEnv.getVariable('aliasedVar');   // 42
+    }});
+  }
+}
+
+g.outer(42);
+assertEq(log, "428442");