1 files changed, 32 insertions, 0 deletions
diff --git a/js/src/jit-test/tests/debug/onExceptionUnwind-resumption-05.js b/js/src/jit-test/tests/debug/onExceptionUnwind-resumption-05.js
new file mode 100644
index 0000000000..00fe2aae44
--- /dev/null
+++ b/js/src/jit-test/tests/debug/onExceptionUnwind-resumption-05.js
@@ -0,0 +1,32 @@
+// Make sure that stacks in completion values are not lost when an exception
+// unwind hook returns undefined.
+
+let g = newGlobal({ newCompartment: true });
+g.eval(`
+  function foo() {
+    bar();
+  }
+  function bar() {
+    throw new Error();
+  }
+`);
+
+let dbg = Debugger(g);
+let unwindHits = 0, popHits = 0;
+dbg.onExceptionUnwind = frame => {
+  unwindHits++;
+  return undefined;
+}
+dbg.onEnterFrame = frame => {
+  frame.onPop = completion => {
+    assertEq(completion.stack.functionDisplayName, "bar");
+    popHits++;
+  };
+};
+
+try {
+  g.eval("foo()");
+} catch (e) {}
+assertEq(unwindHits, 3);
+assertEq(popHits, 3);
+dbg.removeDebuggee(g);