From c8179a99e0d1fd08f6bfa12f63994c155f46907f Mon Sep 17 00:00:00 2001
From: Klemens Morgenstern <klemens.morgenstern@gmx.net>
Date: Sat, 24 May 2025 09:38:36 +0800
Subject: [PATCH] Checking waitpid res for zombie process reaping.

Fixes comment by @mathisloge in issue #447.
---
 include/boost/process/v2/posix/default_launcher.hpp         | 3 ++-
 include/boost/process/v2/posix/fork_and_forget_launcher.hpp | 3 ++-
 include/boost/process/v2/posix/pdfork_launcher.hpp          | 3 ++-
 include/boost/process/v2/posix/vfork_launcher.hpp           | 3 ++-
 4 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/include/boost/process/v2/posix/default_launcher.hpp b/include/boost/process/v2/posix/default_launcher.hpp
index fc826fea2..7a2018c43 100644
--- a/include/boost/process/v2/posix/default_launcher.hpp
+++ b/include/boost/process/v2/posix/default_launcher.hpp
@@ -411,7 +411,8 @@ struct default_launcher
             if (ec)
             {
                 detail::on_error(*this, executable, argv, ec, inits...);
-                do { ::waitpid(pid, nullptr, 0); } while (errno == EINTR);
+                int res = 0;
+                do { res = ::waitpid(pid, nullptr, 0); } while ((res == -1) && (errno == EINTR));
                 return basic_process<Executor>{exec};
             }
         }
diff --git a/include/boost/process/v2/posix/fork_and_forget_launcher.hpp b/include/boost/process/v2/posix/fork_and_forget_launcher.hpp
index f86314dee..26a1e6e45 100644
--- a/include/boost/process/v2/posix/fork_and_forget_launcher.hpp
+++ b/include/boost/process/v2/posix/fork_and_forget_launcher.hpp
@@ -124,7 +124,8 @@ struct fork_and_forget_launcher : default_launcher
             if (ec)
             {
                 detail::on_error(*this, executable, argv, ec, inits...);
-                do { ::waitpid(pid, nullptr, 0); } while (errno == EINTR);
+                int res = 0;
+                do { res = ::waitpid(pid, nullptr, 0); } while ((res != -1)  && (errno == EINTR));
                 return basic_process<Executor>{exec};
             }
         }
diff --git a/include/boost/process/v2/posix/pdfork_launcher.hpp b/include/boost/process/v2/posix/pdfork_launcher.hpp
index 0a082f562..5affc51e9 100644
--- a/include/boost/process/v2/posix/pdfork_launcher.hpp
+++ b/include/boost/process/v2/posix/pdfork_launcher.hpp
@@ -161,7 +161,8 @@ struct pdfork_launcher : default_launcher
             if (ec)
             {
                 detail::on_error(*this, executable, argv, ec, inits...);
-                do { ::waitpid(pid, nullptr, 0); } while (errno == EINTR);
+                int res = 0;
+                do { res = ::waitpid(pid, nullptr, 0); } while ((res == -1) && (errno == EINTR));
                 return basic_process<Executor>{exec};
             }
         }
diff --git a/include/boost/process/v2/posix/vfork_launcher.hpp b/include/boost/process/v2/posix/vfork_launcher.hpp
index bb1b9f2ca..49e2a70b0 100644
--- a/include/boost/process/v2/posix/vfork_launcher.hpp
+++ b/include/boost/process/v2/posix/vfork_launcher.hpp
@@ -121,7 +121,8 @@ struct vfork_launcher :  default_launcher
         if (ec)
         {
             detail::on_error(*this, executable, argv, ec, inits...);
-            do { ::waitpid(pid, nullptr, 0); } while (errno == EINTR);
+            int res = 0;
+            do { res = ::waitpid(pid, nullptr, 0); } while ((res != -1) && (errno == EINTR));
             return basic_process<Executor>{exec};
         }