Funnel/Lua: closing child window disconnects buttons of parent

Summary

Add button to parent to open a child window.

    win:add_button("Help", function()
        local splash = TextWindow.new("HexCalc Reference");

Click button on parent, open child, close child - buttons on parent (except Close) are disconnected.

Related? #16177 (closed), 499d912f, 8afd7a75

Steps to reproduce

https://wiki.wireshark.org/Contrib#other
hexcalc.lua | 1.0.0 | unknown | New Tools menu item to convert between hex and decimal
hexcalc.lua

What is the current bug behavior?

(What actually happens)

What is the expected correct behavior?

(What you should see instead)

Sample capture file

(If possible attach a sample capture file, not screenshot of dissection, showing this issue)

Relevant logs and/or screenshots

(Paste any relevant logs here)

Build information

Version 4.0.0rc2 (v4.0.0rc2-0-g0d976e7a44e9).

Compiled (64-bit) using Microsoft Visual Studio 2022 (VC++ 14.32, build 31332),
with GLib 2.72.3, with PCRE2, with zlib 1.2.12, with Qt 6.2.3, with libpcap,
with Lua 5.2.4, with GnuTLS 3.6.3 and PKCS #11 support, with Gcrypt 1.10.1, with
Kerberos (MIT), with MaxMind, with nghttp2 1.46.0, with brotli, with LZ4, with
Zstandard, with Snappy, with libxml2 2.9.14, with libsmi 0.4.8, with
QtMultimedia, with automatic updates using WinSparkle 0.5.7, with AirPcap, with
SpeexDSP (using bundled resampler), with Minizip, with binary plugins.

Running on 64-bit Windows 10 (21H1), build 19043, with Intel(R) Core(TM)
i5-4300U CPU @ 1.90GHz (with SSE4.2), with 12191 MB of physical memory, with
GLib 2.72.3, with PCRE2 10.40 2022-04-14, with Qt 6.2.3, with Npcap version
1.60, based on libpcap version 1.10.2-PRE-GIT, with c-ares 1.18.1, with GnuTLS
3.6.3, with Gcrypt 1.10.1, with nghttp2 1.46.0, with brotli 1.0.9, with LZ4
1.9.3, with Zstandard 1.5.2, without AirPcap, with light display mode, without
HiDPI, with LC_TYPE=English_United States.utf8, binary plugins supported.