From acbf8065522e3dcbfd3d0a916f13e0097272404f Mon Sep 17 00:00:00 2001
From: Trevor Norris <trev.norris@gmail.com>
Date: Wed, 14 Dec 2016 17:17:10 -0700
Subject: [PATCH] src: return early if nextTickQueue is empty

This brings the node::MakeCallback and node::AsyncWrap::MakeCallback
implementations into alignment in that they return early if the
nextTickQueue is empty after processing the MicrotaskQueue.

Include test to make sure early return happens. Test has text explaining
the conditions for the test to pass, since it relies on internal
mechanisms that aren't guaranteed in the future.

PR-URL: https://github.com/nodejs/node/pull/10274
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: Colin Ihrig <cjihrig@gmail.com>
---
 src/node.cc                                 |  1 +
 test/parallel/test-no-enter-tickcallback.js | 32 +++++++++++++++++++++
 2 files changed, 33 insertions(+)
 create mode 100644 test/parallel/test-no-enter-tickcallback.js

diff --git a/src/node.cc b/src/node.cc
index bdae47ee6c8211..bd8248b2e3c9b4 100644
--- a/src/node.cc
+++ b/src/node.cc
@@ -1274,6 +1274,7 @@ Local<Value> MakeCallback(Environment* env,
 
   if (tick_info->length() == 0) {
     tick_info->set_index(0);
+    return ret;
   }
 
   if (env->tick_callback_function()->Call(process, 0, nullptr).IsEmpty()) {
diff --git a/test/parallel/test-no-enter-tickcallback.js b/test/parallel/test-no-enter-tickcallback.js
new file mode 100644
index 00000000000000..e06628628955be
--- /dev/null
+++ b/test/parallel/test-no-enter-tickcallback.js
@@ -0,0 +1,32 @@
+'use strict';
+
+const common = require('../common');
+const assert = require('assert');
+var allsGood = false;
+var cntr = 0;
+
+process.on('exit', () => {
+  assert.ok(cntr > 0, '_tickDomainCallback was never called');
+});
+
+/**
+ * This test relies upon the following internals to work as specified:
+ *  - require('domain') causes node::Environment::set_tick_callback_function()
+ *    to use process._tickDomainCallback() to process the nextTickQueue;
+ *    replacing process._tickCallback().
+ *  - setImmediate() uses node::MakeCallback() instead of
+ *    node::AsyncWrap::MakeCallback(). Otherwise the test will always pass.
+ *    Have not found a way to verify that node::MakeCallback() is used.
+ */
+process._tickDomainCallback = function _tickDomainCallback() {
+  assert.ok(allsGood, '_tickDomainCallback should not have been called');
+  cntr++;
+};
+
+setImmediate(common.mustCall(() => {
+  require('domain');
+  setImmediate(common.mustCall(() => setImmediate(common.mustCall(() => {
+    allsGood = true;
+    process.nextTick(() => {});
+  }))));
+}));