gnu: lxqt-session: Fix handling of procps@4.

* gnu/packages/patches/lxqt-session-procps-4.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register patch.
* gnu/packages/lxqt.cm (lxqt-session): Apply patch.

1 files changed, 82 insertions, 0 deletions

diff --git a/gnu/packages/patches/lxqt-session-procps-4.patch b/gnu/packages/patches/lxqt-session-procps-4.patch
new file mode 100644
index 0000000000..d10e310723
--- /dev/null
+++ b/gnu/packages/patches/lxqt-session-procps-4.patch
@@ -0,0 +1,82 @@
+From d1db1c791195f3c0cf148e2be8bd46c5a51ca535 Mon Sep 17 00:00:00 2001
+From: Palo Kisa <palo.kisa@gmail.com>
+Date: Tue, 7 Mar 2023 14:21:40 +0100
+Subject: [PATCH 978/978] reaper: Build/Run on systems with procps-ng >= 4.0.0
+ (#456)
+
+On Linux, make it possible to use libproc2 or libprocps whichever is
+available.
+---
+ CMakeLists.txt                  |  6 +++++-
+ lxqt-session/src/procreaper.cpp | 24 +++++++++++++++++++++++-
+ 2 files changed, 28 insertions(+), 2 deletions(-)
+
+diff --git a/CMakeLists.txt b/CMakeLists.txt
+index a3c5e0d..f208600 100644
+--- a/CMakeLists.txt
++++ b/CMakeLists.txt
+@@ -35,7 +35,11 @@ find_package(X11 REQUIRED)
+ message(STATUS "Building with Qt${Qt5Core_VERSION}")
+ find_package(PkgConfig REQUIRED)
+ if (CMAKE_SYSTEM_NAME STREQUAL "Linux")
+-    pkg_search_module(PROCPS REQUIRED libprocps)
++    pkg_search_module(PROCPS REQUIRED libproc2 libprocps)
++    message(STATUS "Using PROCPS -> ${PROCPS_MODULE_NAME} v${PROCPS_VERSION}")
++    if (PROCPS_VERSION VERSION_GREATER_EQUAL 4.0.0)
++        add_definitions("-DUSING_LIBPROC2")
++    endif()
+ endif()
+ 
+ # Please don't move, must be after lxqt
+diff --git a/lxqt-session/src/procreaper.cpp b/lxqt-session/src/procreaper.cpp
+index 2acd030..1ea4bdc 100644
+--- a/lxqt-session/src/procreaper.cpp
++++ b/lxqt-session/src/procreaper.cpp
+@@ -29,7 +29,11 @@
+ #include "log.h"
+ #if defined(Q_OS_LINUX)
+ #include <sys/prctl.h>
+-#include <proc/readproc.h>
++# if defined(USING_LIBPROC2)
++#  include <libproc2/pids.h>
++# else
++#  include <proc/readproc.h>
++# endif
+ #elif defined(Q_OS_FREEBSD)
+ #include <sys/procctl.h>
+ #include <libutil.h>
+@@ -109,6 +113,23 @@ void ProcReaper::stop(const std::set<int64_t> & excludedPids)
+     const pid_t my_pid = ::getpid();
+     std::vector<pid_t> children;
+ #if defined(Q_OS_LINUX)
++# if defined(USING_LIBPROC2)
++    constexpr pids_item items[] = { PIDS_ID_PPID, PIDS_ID_TGID };
++    enum rel_items { rel_ppid, rel_tgid };
++    pids_info * info = nullptr;
++    procps_pids_new(&info, const_cast<pids_item *>(items), sizeof(items) / sizeof(pids_item));
++    pids_stack * stack = nullptr;
++    while ((stack = procps_pids_get(info, PIDS_FETCH_TASKS_ONLY)))
++    {
++        const int ppid = PIDS_VAL(rel_ppid, s_int, stack, info);
++        if (ppid == my_pid)
++        {
++            const int tgid = PIDS_VAL(rel_tgid, s_int, stack, info);
++            children.push_back(tgid);
++        }
++    }
++    procps_pids_unref(&info);
++# else
+     PROCTAB * proc_dir = ::openproc(PROC_FILLSTAT);
+     while (proc_t * proc = ::readproc(proc_dir, nullptr))
+     {
+@@ -119,6 +140,7 @@ void ProcReaper::stop(const std::set<int64_t> & excludedPids)
+         ::freeproc(proc);
+     }
+     ::closeproc(proc_dir);
++# endif
+ #elif defined(Q_OS_FREEBSD)
+     int cnt = 0;
+     if (kinfo_proc *proc_info = kinfo_getallproc(&cnt))
+-- 
+2.39.2
+