File xcb-prevent-fp-division-by-zero.patch of Package libqt5-qtbase.2170

From 40c927e7331ea4ac9ca50de48560b700e657cded Mon Sep 17 00:00:00 2001
From: Giuseppe D'Angelo <giuseppe.dangelo@kdab.com>
Date: Tue, 8 Dec 2015 18:28:24 +0100
Subject: [PATCH] XCB: prevent a fp division by zero
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

For certain devices vci->resolution is zero, which causes a SIGFPE
if FE_INVALID exceptions are enabled. Try to prevent that.

Task-number: QTBUG-42717
Change-Id: I388735f5dfb6218496787dbb74cf0c0f43cc928f
Reviewed-by: Alexander Volkov <a.volkov@rusbitech.ru>
Reviewed-by: Błażej Szczygieł <spaz16@wp.pl>
Reviewed-by: Shawn Rutledge <shawn.rutledge@theqtcompany.com>
---
 src/plugins/platforms/xcb/qxcbconnection_xi2.cpp | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
index 8097cce..1a12370 100644
--- a/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
+++ b/src/plugins/platforms/xcb/qxcbconnection_xi2.cpp
@@ -406,6 +406,9 @@ XInput2TouchDeviceData *QXcbConnection::touchDeviceForId(int id)
 #endif // XCB_USE_XINPUT22
             case XIValuatorClass: {
                 XIValuatorClassInfo *vci = reinterpret_cast<XIValuatorClassInfo *>(classinfo);
+                // Some devices (mice) report a resolution of 0; they will be excluded later,
+                // for now just prevent a division by zero
+                const int vciResolution = vci->resolution ? vci->resolution : 1;
                 if (vci->label == atom(QXcbAtom::AbsMTPositionX))
                     caps |= QTouchDevice::Position | QTouchDevice::NormalizedPosition;
                 else if (vci->label == atom(QXcbAtom::AbsMTTouchMajor))
@@ -414,16 +417,16 @@ XInput2TouchDeviceData *QXcbConnection::touchDeviceForId(int id)
                     caps |= QTouchDevice::Pressure;
                 else if (vci->label == atom(QXcbAtom::RelX)) {
                     hasRelativeCoords = true;
-                    dev->size.setWidth((vci->max - vci->min) * 1000.0 / vci->resolution);
+                    dev->size.setWidth((vci->max - vci->min) * 1000.0 / vciResolution);
                 } else if (vci->label == atom(QXcbAtom::RelY)) {
                     hasRelativeCoords = true;
-                    dev->size.setHeight((vci->max - vci->min) * 1000.0 / vci->resolution);
+                    dev->size.setHeight((vci->max - vci->min) * 1000.0 / vciResolution);
                 } else if (vci->label == atom(QXcbAtom::AbsX)) {
                     caps |= QTouchDevice::Position;
-                    dev->size.setHeight((vci->max - vci->min) * 1000.0 / vci->resolution);
+                    dev->size.setHeight((vci->max - vci->min) * 1000.0 / vciResolution);
                 } else if (vci->label == atom(QXcbAtom::AbsY)) {
                     caps |= QTouchDevice::Position;
-                    dev->size.setWidth((vci->max - vci->min) * 1000.0 / vci->resolution);
+                    dev->size.setWidth((vci->max - vci->min) * 1000.0 / vciResolution);
                 }
                 break;
             }
-- 
2.6.3