From 75bb439f45608b21781d18170a88aaa2aedefb04 Mon Sep 17 00:00:00 2001 From: Fabian Vogt Date: Fri, 9 Mar 2018 18:28:00 +0100 Subject: [PATCH 1/2] Sanitize QXcbScreen's pixelDensity values When the monitor's EDID contains invalid values, we should catch that now and fall back to 96dpi instead of returning unexpected values. --- src/plugins/platforms/xcb/qxcbscreen.cpp | 10 ++++++++++ 1 file changed, 10 insertions(+) Index: qtbase-everywhere-src-5.12.0-beta3/src/plugins/platforms/xcb/qxcbscreen.cpp =================================================================== --- qtbase-everywhere-src-5.12.0-beta3.orig/src/plugins/platforms/xcb/qxcbscreen.cpp +++ qtbase-everywhere-src-5.12.0-beta3/src/plugins/platforms/xcb/qxcbscreen.cpp @@ -752,6 +752,16 @@ void QXcbScreen::updateGeometry(const QR qreal referenceDpi = physicalSize().width() <= 320 ? 128 : 96; m_pixelDensity = qMax(1, qRound(dpi/referenceDpi)); + + if(m_pixelDensity > 1 && qEnvironmentVariableIsEmpty("QT_XCB_FORCE_ACCEPT_DPI")) { + // If we have no physical size or the resolution is untypical, fall back to 1x + if (physicalSize().height() <= 0 + || geometry.height() < 1440 + || m_pixelDensity > 3) { + m_pixelDensity = 1; + } + } + m_geometry = geometry; m_availableGeometry = geometry & m_virtualDesktop->workArea(); QWindowSystemInterface::handleScreenGeometryChange(QPlatformScreen::screen(), m_geometry, m_availableGeometry);