timers: fix regression with clearImmediate()

This commit fixes a regression introduced in 0ed8839a27 that caused
additional queued immediate callbacks to be ignored if
`clearImmediate(immediate)` was called within the callback for
`immediate`.

PR-URL: https://github.com/nodejs/node/pull/9086
Fixes: https://github.com/nodejs/node/issues/9084
Reviewed-By: Rich Trott <rtrott@gmail.com>
Reviewed-By: Jeremiah Senkpiel <fishrock123@rocketmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/test/parallel/test-timers-clearImmediate.js b/test/parallel/test-timers-clearImmediate.js
new file mode 100644
index 0000000000..ab65b7bf1c
--- /dev/null
+++ b/test/parallel/test-timers-clearImmediate.js
@@ -0,0 +1,18 @@
+'use strict';
+require('../common');
+const assert = require('assert');
+
+const N = 3;
+var count = 0;
+function next() {
+  const immediate = setImmediate(function() {
+    clearImmediate(immediate);
+    ++count;
+  });
+}
+for (var i = 0; i < N; ++i)
+  next();
+
+process.on('exit', () => {
+  assert.strictEqual(count, N, `Expected ${N} immediate callback executions`);
+});