kde-plasma/powerdevil: Fix int overflow w/ screen brightness

Upstream commit dd74cdbdd3849fbd86e6613ef7ecab6c7857cb89
KDE-bug: https://bugs.kde.org/show_bug.cgi?id=454161

Package-Manager: Portage-3.0.30, Repoman-3.0.3
Signed-off-by: Andreas Sturmlechner <asturm@gentoo.org>

2 files changed, 131 insertions, 0 deletions

diff --git a/kde-plasma/powerdevil/files/powerdevil-5.25.0-backlight-fix-int-overflow.patch b/kde-plasma/powerdevil/files/powerdevil-5.25.0-backlight-fix-int-overflow.patch
new file mode 100644
index 000000000000..e2003dd42ef0
--- /dev/null
+++ b/kde-plasma/powerdevil/files/powerdevil-5.25.0-backlight-fix-int-overflow.patch
@@ -0,0 +1,59 @@
+From dd74cdbdd3849fbd86e6613ef7ecab6c7857cb89 Mon Sep 17 00:00:00 2001
+From: ivan tkachenko <me@ratijas.tk>
+Date: Thu, 16 Jun 2022 00:17:42 +0300
+Subject: [PATCH] upower: Prevent integer overflow during new brightness
+ computation
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Provably, if two integers can fit in 31 bits each, the result of their
+multiplication is expressible in 62 bits (let alone 63 available). So,
+this should be safe. And the division can't do much harm: the divisor
+is always at least 1, and worst case scenario — it would be so big that
+the overall results becomes zero.
+
+This code still assumes that the allowed brightness values can fit in 32
+bits int, which is not totally unreasonable so far.
+
+BUG: 454161
+
+
+(cherry picked from commit 2ebe655d220c9167b66893a823b2fff2e2b8a531)
+---
+ daemon/backends/upower/backlighthelper.cpp | 11 +++++++----
+ 1 file changed, 7 insertions(+), 4 deletions(-)
+
+diff --git a/daemon/backends/upower/backlighthelper.cpp b/daemon/backends/upower/backlighthelper.cpp
+index 84c6aee1..c9e34e4b 100644
+--- a/daemon/backends/upower/backlighthelper.cpp
++++ b/daemon/backends/upower/backlighthelper.cpp
+@@ -27,6 +27,7 @@
+ #include <KLocalizedString>
+ 
+ #include <algorithm>
++#include <climits>
+ #include <sys/utsname.h>
+ 
+ #ifdef Q_OS_FREEBSD
+@@ -318,11 +319,13 @@ bool BacklightHelper::writeBrightness(int brightness) const
+ #else
+ 
+     if (!m_devices.isEmpty()) {
+-        int first_maxbrightness = m_devices.constFirst().second;
+-        if (first_maxbrightness <= 0)
+-            first_maxbrightness = 1;
++        const int first_maxbrightness = std::max(1, m_devices.constFirst().second);
+         for (const auto &device : m_devices) {
+-            writeToDevice(device.first, brightness * device.second / first_maxbrightness);
++            // Some monitor brightness values are ridiculously high, and can easily overflow during computation
++            const qint64 new_brightness_64 = static_cast<qint64>(brightness) * static_cast<qint64>(device.second) / static_cast<qint64>(first_maxbrightness);
++            // cautiously truncate it back
++            const int new_brightness = static_cast<int>(std::min(static_cast<qint64>(std::numeric_limits<int>::max()), new_brightness_64));
++            writeToDevice(device.first, new_brightness);
+         }
+     }
+ 
+-- 
+GitLab
+
diff --git a/kde-plasma/powerdevil/powerdevil-5.25.0-r1.ebuild b/kde-plasma/powerdevil/powerdevil-5.25.0-r1.ebuild
new file mode 100644
index 000000000000..e12b3e0ed115
--- /dev/null
+++ b/kde-plasma/powerdevil/powerdevil-5.25.0-r1.ebuild
@@ -0,0 +1,72 @@
+# Copyright 1999-2022 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=8
+
+ECM_HANDBOOK="forceoptional"
+KFMIN=5.94.0
+PVCUT=$(ver_cut 1-3)
+QTMIN=5.15.3
+inherit ecm kde.org
+
+DESCRIPTION="Power management for KDE Plasma Shell"
+HOMEPAGE="https://invent.kde.org/plasma/powerdevil"
+
+LICENSE="GPL-2" # TODO: CHECK
+SLOT="5"
+KEYWORDS="~amd64 ~arm ~arm64 ~ppc64 ~riscv ~x86"
+IUSE="brightness-control caps +wireless"
+
+DEPEND="
+	>=dev-qt/qtdbus-${QTMIN}:5
+	>=dev-qt/qtgui-${QTMIN}:5
+	>=dev-qt/qtwidgets-${QTMIN}:5
+	>=dev-qt/qtx11extras-${QTMIN}:5
+	>=kde-frameworks/kactivities-${KFMIN}:5
+	>=kde-frameworks/kauth-${KFMIN}:5[policykit]
+	>=kde-frameworks/kcompletion-${KFMIN}:5
+	>=kde-frameworks/kconfig-${KFMIN}:5
+	>=kde-frameworks/kconfigwidgets-${KFMIN}:5
+	>=kde-frameworks/kcoreaddons-${KFMIN}:5
+	>=kde-frameworks/kcrash-${KFMIN}:5
+	>=kde-frameworks/kdbusaddons-${KFMIN}:5
+	>=kde-frameworks/kglobalaccel-${KFMIN}:5
+	>=kde-frameworks/ki18n-${KFMIN}:5
+	>=kde-frameworks/kidletime-${KFMIN}:5
+	>=kde-frameworks/kio-${KFMIN}:5
+	>=kde-frameworks/kirigami-${KFMIN}:5
+	>=kde-frameworks/knotifications-${KFMIN}:5
+	>=kde-frameworks/knotifyconfig-${KFMIN}:5
+	>=kde-frameworks/kservice-${KFMIN}:5
+	>=kde-frameworks/kwayland-${KFMIN}:5
+	>=kde-frameworks/kwidgetsaddons-${KFMIN}:5
+	>=kde-frameworks/kxmlgui-${KFMIN}:5
+	>=kde-frameworks/solid-${KFMIN}:5
+	>=kde-plasma/libkscreen-${PVCUT}:5
+	>=kde-plasma/libkworkspace-${PVCUT}:5
+	virtual/libudev:=
+	x11-libs/libxcb
+	brightness-control? ( app-misc/ddcutil:= )
+	caps? ( sys-libs/libcap )
+	wireless? (
+		>=kde-frameworks/bluez-qt-${KFMIN}:5
+		>=kde-frameworks/networkmanager-qt-${KFMIN}:5
+	)
+"
+RDEPEND="${DEPEND}
+	>=kde-plasma/kde-cli-tools-${PVCUT}:5
+	>=sys-power/upower-0.9.23
+"
+
+PATCHES=( "${FILESDIR}/${P}-backlight-fix-int-overflow.patch" )
+
+src_configure() {
+	local mycmakeargs=(
+		-DHAVE_DDCUTIL=$(usex brightness-control)
+		$(cmake_use_find_package caps Libcap)
+		$(cmake_use_find_package wireless KF5BluezQt)
+		$(cmake_use_find_package wireless KF5NetworkManagerQt)
+	)
+
+	ecm_src_configure
+}