From a045f4f0e65be77f78d305e6304cc77a7fb4369d Mon Sep 17 00:00:00 2001
From: Kovid Goyal <kovid@kovidgoyal.net>
Date: Thu, 3 Nov 2016 18:04:39 +0530
Subject: [PATCH] Retrieve child exit status before shutting down

---
 kitty/main.py  |  7 ++++---
 kitty/utils.py | 13 ++++++++++++-
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/kitty/main.py b/kitty/main.py
index cc54cd52a..77fe23e1f 100644
--- a/kitty/main.py
+++ b/kitty/main.py
@@ -13,7 +13,7 @@ from gettext import gettext as _
 from .config import load_config
 from .constants import appname, str_version, config_dir
 from .boss import Boss
-from .utils import fork_child, hangup
+from .utils import fork_child, hangup, get_child_status
 from .shaders import GL_VERSION
 from .fast_data_types import glewInit, enable_automatic_opengl_error_checking
 import glfw
@@ -56,7 +56,9 @@ def run_app(opts, args):
         glfw.glfwMakeContextCurrent(window)
         glewInit()
         glfw.glfwSwapInterval(1)
+        child = args.args or [pwd.getpwuid(os.geteuid()).pw_shell or '/bin/sh']
         boss = Boss(window, window_width, window_height, opts, args)
+        fork_child(child, args.directory, opts)
         glfw.glfwSetFramebufferSizeCallback(window, boss.on_window_resize)
         boss.start()
         try:
@@ -69,6 +71,7 @@ def run_app(opts, args):
                 boss.close()
                 boss.join()
             boss.destroy()
+            get_child_status()  # Ensure child does not become zombie
     finally:
         glfw.glfwDestroyWindow(window)
 
@@ -93,8 +96,6 @@ def main():
     if not glfw.glfwInit():
         raise SystemExit('GLFW initialization failed')
     try:
-        child = args.args or [pwd.getpwuid(os.geteuid()).pw_shell or '/bin/sh']
-        fork_child(child, args.directory, opts)
         if args.profile:
             tf = tempfile.NamedTemporaryFile(prefix='kitty-profiling-stats-')
             args.profile = tf.name
diff --git a/kitty/utils.py b/kitty/utils.py
index 4fa01ddff..e707d6d2b 100644
--- a/kitty/utils.py
+++ b/kitty/utils.py
@@ -84,10 +84,21 @@ def hangup():
     if hasattr(fork_child, 'pid'):
         pid = fork_child.pid
         del fork_child.pid
-        pgrp = os.getpgid(pid)
+        try:
+            pgrp = os.getpgid(pid)
+        except ProcessLookupError:
+            return
         os.killpg(pgrp, signal.SIGHUP)
         os.close(create_pty()[0])
 
+
+def get_child_status():
+    if hasattr(fork_child, 'pid'):
+        try:
+            return os.waitid(os.P_PID, fork_child.pid, os.WEXITED | os.WNOHANG)
+        except ChildProcessError:
+            del fork_child.pid
+
 base_size = sys.getsizeof('')