child_process: clean event listener correctly

I was working on AbortSignal for spawn and noticed there is a leak in
the current code for AbortSignal support in child_process since it
removes the wrong listener. I used the new signal as argument feature
to make removing the listener easier and added a test.

PR-URL: https://github.com/nodejs/node/pull/36424
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Rich Trott <rtrott@gmail.com>

1 files changed, 4 insertions, 5 deletions

diff --git a/lib/child_process.js b/lib/child_process.js
index ae5a5f6587..29a6450210 100644
--- a/lib/child_process.js
+++ b/lib/child_process.js
@@ -378,14 +378,13 @@ function execFile(file /* , args, options, callback */) {
     if (options.signal.aborted) {
       process.nextTick(() => kill());
     } else {
+      const childController = new AbortController();
       options.signal.addEventListener('abort', () => {
-        if (!ex) {
+        if (!ex)
           ex = new AbortError();
-        }
         kill();
-      });
-      const remove = () => options.signal.removeEventListener('abort', kill);
-      child.once('close', remove);
+      }, { signal: childController.signal });
+      child.once('close', () => childController.abort());
     }
   }