dev-qt/qtgui: Fix multiscreen regression

"There is a bug in Qt 5.15.1 that seriously affects multiscreen. We get
a bunch of reports every day. Effectively a screen change signal goes
missing and Plasma naturally breaks."

See also: https://mail.kde.org/pipermail/distributions/2020-September/000866.html
KDE-Bug: https://bugs.kde.org/show_bug.cgi?id=426496
QTBUG: https://bugreports.qt.io/browse/QTBUG-86604
Cherry-picked from: https://codereview.qt-project.org/c/qt/qtbase/+/315721

Package-Manager: Portage-3.0.8, Repoman-3.0.1
Signed-off-by: Andreas Sturmlechner <asturm@gentoo.org>

2 files changed, 271 insertions, 0 deletions

diff --git a/dev-qt/qtgui/files/qtgui-5.15.1-emit-qscreen-geometrychanged-when-dpi-changes.patch b/dev-qt/qtgui/files/qtgui-5.15.1-emit-qscreen-geometrychanged-when-dpi-changes.patch
new file mode 100644
index 000000000000..3e4187b22a06
--- /dev/null
+++ b/dev-qt/qtgui/files/qtgui-5.15.1-emit-qscreen-geometrychanged-when-dpi-changes.patch
@@ -0,0 +1,86 @@
+From 65243ad7aef48af4689ea4454916b504025b5051 Mon Sep 17 00:00:00 2001
+From: Friedemann Kleint <Friedemann.Kleint@qt.io>
+Date: Fri, 25 Sep 2020 14:10:58 +0200
+Subject: [PATCH] Emit QScreen::geometryChanged when the logical DPI changes
+
+Add the missing call to QScreenPrivate::emitGeometryChangeSignals()
+along with an emission of physicalDotsPerInchChanged()
+since that is calculated from geometry and physical size.
+
+Rearrange the code in
+QGuiApplicationPrivate::processScreenGeometryChange()
+to prevent duplicate emissions of geometryChanged(),
+physicalDotsPerInchChanged() which this change would introduce.
+
+Amends 5290027e3bab75f14fc0a2b7c206594d9cb91e76.
+
+Task-number: QTBUG-76902
+Task-number: QTBUG-79248
+Fixes: QTBUG-86604
+Change-Id: I3dc2ec5ccd9c6413e92f9246242f323e8afc5e57
+Reviewed-by: David Edmundson <davidedmundson@kde.org>
+(cherry picked from commit 5c7307775d32ae0a54acad8ae7a1c9d3cff7d45e)
+Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
+---
+ src/gui/kernel/qguiapplication.cpp | 11 +++++------
+ src/gui/kernel/qscreen.cpp         |  6 ++++++
+ 2 files changed, 11 insertions(+), 6 deletions(-)
+
+diff --git a/src/gui/kernel/qguiapplication.cpp b/src/gui/kernel/qguiapplication.cpp
+index 239a78313c5..ef090605819 100644
+--- a/src/gui/kernel/qguiapplication.cpp
++++ b/src/gui/kernel/qguiapplication.cpp
+@@ -3162,13 +3162,14 @@ void QGuiApplicationPrivate::processScreenGeometryChange(QWindowSystemInterfaceP
+     bool availableGeometryChanged = e->availableGeometry != s->d_func()->availableGeometry;
+     s->d_func()->availableGeometry = e->availableGeometry;
+ 
+-    if (geometryChanged) {
+-        Qt::ScreenOrientation primaryOrientation = s->primaryOrientation();
++    const Qt::ScreenOrientation primaryOrientation = s->primaryOrientation();
++    if (geometryChanged)
+         s->d_func()->updatePrimaryOrientation();
+ 
+-        emit s->geometryChanged(s->geometry());
++    s->d_func()->emitGeometryChangeSignals(geometryChanged, availableGeometryChanged);
++
++    if (geometryChanged) {
+         emit s->physicalSizeChanged(s->physicalSize());
+-        emit s->physicalDotsPerInchChanged(s->physicalDotsPerInch());
+         emit s->logicalDotsPerInchChanged(s->logicalDotsPerInch());
+ 
+         if (s->primaryOrientation() != primaryOrientation)
+@@ -3178,8 +3179,6 @@ void QGuiApplicationPrivate::processScreenGeometryChange(QWindowSystemInterfaceP
+             updateFilteredScreenOrientation(s);
+     }
+ 
+-    s->d_func()->emitGeometryChangeSignals(geometryChanged, availableGeometryChanged);
+-
+     resetCachedDevicePixelRatio();
+ }
+ 
+diff --git a/src/gui/kernel/qscreen.cpp b/src/gui/kernel/qscreen.cpp
+index df628fcc73a..a1afc1ba143 100644
+--- a/src/gui/kernel/qscreen.cpp
++++ b/src/gui/kernel/qscreen.cpp
+@@ -88,6 +88,9 @@ void QScreenPrivate::updateGeometriesWithSignals()
+ void QScreenPrivate::emitGeometryChangeSignals(bool geometryChanged, bool availableGeometryChanged)
+ {
+     Q_Q(QScreen);
++    if (geometryChanged)
++        emit q->geometryChanged(geometry);
++
+     if (availableGeometryChanged)
+         emit q->availableGeometryChanged(availableGeometry);
+ 
+@@ -96,6 +99,9 @@ void QScreenPrivate::emitGeometryChangeSignals(bool geometryChanged, bool availa
+         for (QScreen* sibling : siblings)
+             emit sibling->virtualGeometryChanged(sibling->virtualGeometry());
+     }
++
++    if (geometryChanged)
++        emit q->physicalDotsPerInchChanged(q->physicalDotsPerInch());
+ }
+ 
+ void QScreenPrivate::setPlatformScreen(QPlatformScreen *screen)
+-- 
+2.16.3
diff --git a/dev-qt/qtgui/qtgui-5.15.1-r1.ebuild b/dev-qt/qtgui/qtgui-5.15.1-r1.ebuild
new file mode 100644
index 000000000000..be95e1eff6bf
--- /dev/null
+++ b/dev-qt/qtgui/qtgui-5.15.1-r1.ebuild
@@ -0,0 +1,185 @@
+# Copyright 1999-2020 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+QT5_MODULE="qtbase"
+inherit qt5-build
+
+DESCRIPTION="The GUI module and platform plugins for the Qt5 framework"
+SLOT=5/$(ver_cut 1-3) # bug 707658
+
+if [[ ${QT5_BUILD_TYPE} == release ]]; then
+	KEYWORDS="~amd64 ~arm ~arm64 ~hppa ~ppc ~ppc64 ~sparc ~x86"
+fi
+
+# TODO: linuxfb
+
+IUSE="accessibility dbus egl eglfs evdev +gif gles2-only ibus jpeg
+	+libinput +png tslib tuio +udev vnc vulkan wayland +X"
+REQUIRED_USE="
+	|| ( eglfs X )
+	accessibility? ( dbus X )
+	eglfs? ( egl )
+	ibus? ( dbus )
+	libinput? ( udev )
+	X? ( gles2-only? ( egl ) )
+"
+
+RDEPEND="
+	dev-libs/glib:2
+	~dev-qt/qtcore-${PV}:5=
+	dev-util/gtk-update-icon-cache
+	media-libs/fontconfig
+	>=media-libs/freetype-2.6.1:2
+	>=media-libs/harfbuzz-1.6.0:=
+	sys-libs/zlib:=
+	dbus? ( ~dev-qt/qtdbus-${PV} )
+	egl? ( media-libs/mesa[egl] )
+	eglfs? (
+		media-libs/mesa[gbm]
+		x11-libs/libdrm
+	)
+	evdev? ( sys-libs/mtdev )
+	gles2-only? ( media-libs/mesa[gles2] )
+	!gles2-only? ( virtual/opengl )
+	jpeg? ( virtual/jpeg:0 )
+	libinput? (
+		dev-libs/libinput:=
+		>=x11-libs/libxkbcommon-0.5.0
+	)
+	png? ( media-libs/libpng:0= )
+	tslib? ( >=x11-libs/tslib-1.21 )
+	tuio? ( ~dev-qt/qtnetwork-${PV} )
+	udev? ( virtual/libudev:= )
+	vnc? ( ~dev-qt/qtnetwork-${PV} )
+	vulkan? ( dev-util/vulkan-headers )
+	X? (
+		x11-libs/libICE
+		x11-libs/libSM
+		x11-libs/libX11
+		>=x11-libs/libxcb-1.12:=[xkb]
+		>=x11-libs/libxkbcommon-0.5.0[X]
+		x11-libs/xcb-util-image
+		x11-libs/xcb-util-keysyms
+		x11-libs/xcb-util-renderutil
+		x11-libs/xcb-util-wm
+	)
+"
+DEPEND="${RDEPEND}
+	evdev? ( sys-kernel/linux-headers )
+	udev? ( sys-kernel/linux-headers )
+"
+PDEPEND="
+	ibus? ( app-i18n/ibus )
+	wayland? ( ~dev-qt/qtwayland-${PV} )
+"
+
+QT5_TARGET_SUBDIRS=(
+	src/tools/qvkgen
+	src/gui
+	src/openglextensions
+	src/platformheaders
+	src/platformsupport
+	src/plugins/generic
+	src/plugins/imageformats
+	src/plugins/platforms
+	src/plugins/platforminputcontexts
+)
+
+QT5_GENTOO_CONFIG=(
+	accessibility:accessibility-atspi-bridge
+	egl:egl:
+	eglfs:eglfs:
+	eglfs:eglfs_egldevice:
+	eglfs:eglfs_gbm:
+	evdev:evdev:
+	evdev:mtdev:
+	:fontconfig:
+	:system-freetype:FREETYPE
+	!:no-freetype:
+	!gif:no-gif:
+	gles2-only::OPENGL_ES
+	gles2-only:opengles2:OPENGL_ES_2
+	!:no-gui:
+	:system-harfbuzz:
+	!:no-harfbuzz:
+	jpeg:system-jpeg:IMAGEFORMAT_JPEG
+	!jpeg:no-jpeg:
+	libinput
+	libinput:xkbcommon:
+	:opengl
+	png:png:
+	png:system-png:IMAGEFORMAT_PNG
+	!png:no-png:
+	tslib:tslib:
+	udev:libudev:
+	vulkan:vulkan:
+	X:xcb:
+	X:xcb-glx:
+	X:xcb-plugin:
+	X:xcb-render:
+	X:xcb-sm:
+	X:xcb-xlib:
+	X:xcb-xinput:
+)
+
+QT5_GENTOO_PRIVATE_CONFIG=(
+	:gui
+)
+
+PATCHES=(
+	"${FILESDIR}/qt-5.12-gcc-avx2.patch" # bug 672946
+	"${FILESDIR}/${PN}-5.14.1-cmake-macro-backward-compat.patch" # bug 703306
+	"${FILESDIR}/${P}-emit-qscreen-geometrychanged-when-dpi-changes.patch" # QTBUG-86604
+)
+
+src_prepare() {
+	# don't add -O3 to CXXFLAGS, bug 549140
+	sed -i -e '/CONFIG\s*+=/s/optimize_full//' src/gui/gui.pro || die
+
+	# egl_x11 is activated when both egl and X are enabled
+	use egl && QT5_GENTOO_CONFIG+=(X:egl_x11:) || QT5_GENTOO_CONFIG+=(egl:egl_x11:)
+
+	qt_use_disable_config dbus dbus \
+		src/platformsupport/themes/genericunix/genericunix.pri
+
+	qt_use_disable_config tuio tuiotouch src/plugins/generic/generic.pro
+
+	qt_use_disable_mod ibus dbus \
+		src/plugins/platforminputcontexts/platforminputcontexts.pro
+
+	use vnc || sed -i -e '/SUBDIRS += vnc/d' \
+		src/plugins/platforms/platforms.pro || die
+
+	qt5-build_src_prepare
+}
+
+src_configure() {
+	local myconf=(
+		$(usex dbus -dbus-linked '')
+		$(qt_use egl)
+		$(qt_use eglfs)
+		$(usex eglfs '-gbm -kms' '')
+		$(qt_use evdev)
+		$(qt_use evdev mtdev)
+		-fontconfig
+		-system-freetype
+		$(usex gif '' -no-gif)
+		-gui
+		-system-harfbuzz
+		$(qt_use jpeg libjpeg system)
+		$(qt_use libinput)
+		-opengl $(usex gles2-only es2 desktop)
+		$(qt_use png libpng system)
+		$(qt_use tslib)
+		$(qt_use udev libudev)
+		$(qt_use vulkan)
+		$(qt_use X xcb)
+		$(usex X '-xcb-xlib' '')
+	)
+	if use libinput || use X; then
+		myconf+=( -xkbcommon )
+	fi
+	qt5-build_src_configure
+}