From 5385853f3ffa6adbd558e741c7e4366ec0b2ff0e Mon Sep 17 00:00:00 2001
From: Geoffrey McRae <geoff@hostfission.com>
Date: Sun, 18 Sep 2022 10:10:13 +1000
Subject: [PATCH] [client] x11: set _NET_WM_PID

Fixes #1013
---
 client/displayservers/X11/atoms.h |  1 +
 client/displayservers/X11/x11.c   | 15 +++++++++++++++
 2 files changed, 16 insertions(+)

diff --git a/client/displayservers/X11/atoms.h b/client/displayservers/X11/atoms.h
index c1446bf9..1126e249 100644
--- a/client/displayservers/X11/atoms.h
+++ b/client/displayservers/X11/atoms.h
@@ -38,6 +38,7 @@
   DEF_ATOM(_NET_WM_WINDOW_TYPE, True) \
   DEF_ATOM(_NET_WM_WINDOW_TYPE_NORMAL, True) \
   DEF_ATOM(_NET_WM_WINDOW_TYPE_UTILITY, True) \
+  DEF_ATOM(_NET_WM_PID, True) \
   DEF_ATOM(WM_DELETE_WINDOW, True) \
   DEF_ATOM(_MOTIF_WM_HINTS, True) \
   \
diff --git a/client/displayservers/X11/x11.c b/client/displayservers/X11/x11.c
index 40f92c02..f36db977 100644
--- a/client/displayservers/X11/x11.c
+++ b/client/displayservers/X11/x11.c
@@ -350,6 +350,21 @@ static bool x11Init(const LG_DSInitParams params)
   // check for Extended Window Manager Hints support
   x11CheckEWMHSupport();
 
+  if (x11atoms._NET_WM_PID)
+  {
+    pid_t pid = getpid();
+    XChangeProperty(
+      x11.display,
+      x11.window,
+      x11atoms._NET_WM_PID,
+      XA_CARDINAL,
+      32,
+      PropModeReplace,
+      (unsigned char *)&pid,
+      1
+    );
+  }
+
   if (params.borderless)
   {
     if (x11atoms._MOTIF_WM_HINTS)