From 264f003b0e8b761c606951239cbeb9fc5413f453 Mon Sep 17 00:00:00 2001
From: Anna Henningsen <anna@addaleax.net>
Date: Fri, 7 Aug 2020 16:24:05 +0200
Subject: [PATCH] src: fix `size` underflow in CallbackQueue

Only decrease the size when actually removing items.

PR-URL: https://github.com/nodejs/node/pull/34662
Fixes: https://github.com/nodejs/node/issues/34657
Refs: https://github.com/nodejs/node/pull/34572
Reviewed-By: Gabriel Schulhof <gabriel.schulhof@intel.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
---
 src/callback_queue-inl.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/callback_queue-inl.h b/src/callback_queue-inl.h
index e83c81cd0dd802..8c6919912e161b 100644
--- a/src/callback_queue-inl.h
+++ b/src/callback_queue-inl.h
@@ -22,8 +22,8 @@ CallbackQueue<R, Args...>::Shift() {
     head_ = ret->get_next();
     if (!head_)
       tail_ = nullptr;  // The queue is now empty.
+    size_--;
   }
-  size_--;
   return ret;
 }