From 9759b249e97d4b05644309fc70ae9277b347027e Mon Sep 17 00:00:00 2001
From: Paul Eggert <eggert@cs.ucla.edu>
Date: Sun, 21 May 2017 02:00:02 -0700
Subject: [PATCH] Work around macOS bug in create_process, too

* src/process.c (create_process) [DARWIN_OS]:
Reset SIGCHLD after vfork here, too.
---
 src/process.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/process.c b/src/process.c
index c30173955d2..2a1c2eecde3 100644
--- a/src/process.c
+++ b/src/process.c
@@ -2051,11 +2051,16 @@ create_process (Lisp_Object process, char **new_argv, Lisp_Object current_dir)
 
 #ifdef DARWIN_OS
   /* Darwin doesn't let us run setsid after a vfork, so use fork when
-     necessary. */
+     necessary.  Also, reset SIGCHLD handling after a vfork, as
+     apparently macOS can mistakenly deliver SIGCHLD to the child.  */
   if (pty_flag)
     pid = fork ();
   else
-    pid = vfork ();
+    {
+      pid = vfork ();
+      if (pid == 0)
+	signal (SIGCHLD, SIG_DFL);
+    }
 #else
   pid = vfork ();
 #endif
-- 
2.39.2