From 2bc95990571f82ddfc685fadff4847abff4362e3 Mon Sep 17 00:00:00 2001
From: Max Romanov <max.romanov@nginx.com>
Date: Wed, 24 Nov 2021 13:11:50 +0300
Subject: [PATCH] Fixing zombie process appearance and hang up on shutdown.

After the c8790d2a89bb commit, the SIGCHLD handler may return before processing
all awaiting PIDs.  To avoid zombie processes and ensure successful main
process termination, waitpid() must be called until an error is returned.

This closes #600 issue on GitHub.
---
 src/nxt_main_process.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/nxt_main_process.c b/src/nxt_main_process.c
index 3914c041..9883f04c 100644
--- a/src/nxt_main_process.c
+++ b/src/nxt_main_process.c
@@ -972,9 +972,11 @@ nxt_main_process_sigchld_handler(nxt_task_t *task, void *obj, void *data)
 
                 if (rt->nprocesses <= 1) {
                     nxt_runtime_quit(task, 0);
+
+                    return;
                 }
 
-                return;
+                continue;
             }
 
             nxt_port_remove_notify_others(task, process);