Merge remote-tracking branch 'origin/5.5' into 5.6

Conflicts:
	src/corelib/io/qstorageinfo_unix.cpp
	src/plugins/platforms/windows/qwindowsmousehandler.cpp
	src/widgets/styles/qwindowsvistastyle.cpp

Change-Id: Ie1725933815891cc8c86258d4c0e8ed0ab386edf

16 files changed, 167 insertions, 57 deletions

diff --git a/src/3rdparty/forkfd/forkfd.c b/src/3rdparty/forkfd/forkfd.c
index e55ef47683..3bf7fc3deb 100644
--- a/src/3rdparty/forkfd/forkfd.c
+++ b/src/3rdparty/forkfd/forkfd.c
@@ -61,6 +61,9 @@
 #if _POSIX_VERSION-0 >= 200809L || _XOPEN_VERSION-0 >= 500
 #  define HAVE_WAITID   1
 #endif
+#if !defined(WEXITED) || !defined(WNOWAIT)
+#  undef HAVE_WAITID
+#endif
 
 #if defined(__FreeBSD__)
 #  define HAVE_PIPE2    1
diff --git a/src/android/jar/src/org/qtproject/qt5/android/QtNative.java b/src/android/jar/src/org/qtproject/qt5/android/QtNative.java
index 371e4e4a61..1b7ec8abbb 100644
--- a/src/android/jar/src/org/qtproject/qt5/android/QtNative.java
+++ b/src/android/jar/src/org/qtproject/qt5/android/QtNative.java
@@ -107,13 +107,15 @@ public class QtNative
         }
     }
 
-    public static boolean openURL(String url)
+    public static boolean openURL(String url, String mime)
     {
         boolean ok = true;
 
         try {
             Uri uri = Uri.parse(url);
             Intent intent = new Intent(Intent.ACTION_VIEW, uri);
+            if (!mime.isEmpty())
+                intent.setDataAndType(uri, mime);
             activity().startActivity(intent);
         } catch (Exception e) {
             e.printStackTrace();
diff --git a/src/angle/src/compiler/preprocessor/preprocessor.pro b/src/angle/src/compiler/preprocessor/preprocessor.pro
index 759a3399b4..12f644870d 100644
--- a/src/angle/src/compiler/preprocessor/preprocessor.pro
+++ b/src/angle/src/compiler/preprocessor/preprocessor.pro
@@ -41,15 +41,15 @@ SOURCES += \
     $$ANGLE_DIR/src/compiler/preprocessor/Token.cpp
 
 # NOTE: 'flex' and 'bison' can be found in qt5/gnuwin32/bin
-flex.commands = $$addGnuPath(flex) --noline --nounistd --outfile=${QMAKE_FILE_BASE}.cpp ${QMAKE_FILE_NAME}
-flex.output = ${QMAKE_FILE_BASE}.cpp
+flex.commands = $$addGnuPath(flex) --noline --nounistd --outfile=${QMAKE_FILE_OUT} ${QMAKE_FILE_NAME}
+flex.output = $${BUILDSUBDIR}${QMAKE_FILE_BASE}.cpp
 flex.input = FLEX_SOURCES
 flex.dependency_type = TYPE_C
 flex.variable_out = GENERATED_SOURCES
 QMAKE_EXTRA_COMPILERS += flex
 
-bison.commands = $$addGnuPath(bison) --no-lines --skeleton=yacc.c  --output=${QMAKE_FILE_BASE}.cpp ${QMAKE_FILE_NAME}
-bison.output = ${QMAKE_FILE_BASE}.cpp
+bison.commands = $$addGnuPath(bison) --no-lines --skeleton=yacc.c --output=${QMAKE_FILE_OUT} ${QMAKE_FILE_NAME}
+bison.output = $${BUILDSUBDIR}${QMAKE_FILE_BASE}.cpp
 bison.input = BISON_SOURCES
 bison.dependency_type = TYPE_C
 bison.variable_out = GENERATED_SOURCES
diff --git a/src/angle/src/compiler/translator.pro b/src/angle/src/compiler/translator.pro
index 9572a51ad4..b40aa96319 100644
--- a/src/angle/src/compiler/translator.pro
+++ b/src/angle/src/compiler/translator.pro
@@ -163,16 +163,18 @@ SOURCES += \
 
 
 # NOTE: 'flex' and 'bison' can be found in qt5/gnuwin32/bin
-flex.commands = $$addGnuPath(flex) --noline --nounistd --outfile=${QMAKE_FILE_BASE}_lex.cpp ${QMAKE_FILE_NAME}
-flex.output = ${QMAKE_FILE_BASE}_lex.cpp
+flex.commands = $$addGnuPath(flex) --noline --nounistd --outfile=${QMAKE_FILE_OUT} ${QMAKE_FILE_NAME}
+flex.output = $${BUILDSUBDIR}${QMAKE_FILE_BASE}_lex.cpp
 flex.input = FLEX_SOURCES
 flex.dependency_type = TYPE_C
 flex.variable_out = GENERATED_SOURCES
 QMAKE_EXTRA_COMPILERS += flex
 
-bison.commands = $$addGnuPath(bison) --no-lines --skeleton=yacc.c --defines=${QMAKE_FILE_BASE}_tab.h \
-                --output=${QMAKE_FILE_BASE}_tab.cpp ${QMAKE_FILE_NAME}
-bison.output = ${QMAKE_FILE_BASE}_tab.h
+defineReplace(myDirName) { return($$dirname(1)) }
+bison.commands = $$addGnuPath(bison) --no-lines --skeleton=yacc.c --defines=${QMAKE_FILE_OUT} \
+                --output=${QMAKE_FUNC_FILE_OUT_myDirName}$$QMAKE_DIR_SEP${QMAKE_FILE_OUT_BASE}.cpp \
+                ${QMAKE_FILE_NAME}
+bison.output = $${BUILDSUBDIR}${QMAKE_FILE_BASE}_tab.h
 bison.input = BISON_SOURCES
 bison.dependency_type = TYPE_C
 bison.variable_out = GENERATED_SOURCES
@@ -182,10 +184,10 @@ QMAKE_EXTRA_COMPILERS += bison
 # have one output file even if the command generates two.
 MAKEFILE_NOOP_COMMAND = @echo -n
 msvc: MAKEFILE_NOOP_COMMAND = @echo >NUL
-bison_impl.output = ${QMAKE_FILE_BASE}_tab.cpp
+bison_impl.output = $${BUILDSUBDIR}${QMAKE_FILE_BASE}_tab.cpp
 bison_impl.input = BISON_SOURCES
 bison_impl.commands = $$MAKEFILE_NOOP_COMMAND
-bison_impl.depends = ${QMAKE_FILE_BASE}_tab.h
-bison_impl.output = ${QMAKE_FILE_BASE}_tab.cpp
+bison_impl.depends = $${BUILDSUBDIR}${QMAKE_FILE_BASE}_tab.h
+bison_impl.output = $${BUILDSUBDIR}${QMAKE_FILE_BASE}_tab.cpp
 bison_impl.variable_out = GENERATED_SOURCES
 QMAKE_EXTRA_COMPILERS += bison_impl
diff --git a/src/angle/src/config.pri b/src/angle/src/config.pri
index 0d75245ec5..085913ac83 100644
--- a/src/angle/src/config.pri
+++ b/src/angle/src/config.pri
@@ -53,6 +53,8 @@ CONFIG(debug, debug|release) {
     DEFINES += NDEBUG
 }
 
+!isEmpty(BUILD_PASS): BUILDSUBDIR = $$lower($$BUILD_PASS)/
+
 # c++11 is needed by MinGW to get support for unordered_map.
 CONFIG += stl exceptions c++11
 
diff --git a/src/corelib/io/qstorageinfo_unix.cpp b/src/corelib/io/qstorageinfo_unix.cpp
index 262703b9e6..e365d8d7e6 100644
--- a/src/corelib/io/qstorageinfo_unix.cpp
+++ b/src/corelib/io/qstorageinfo_unix.cpp
@@ -68,8 +68,8 @@
 
 #if defined(Q_OS_BSD4)
 #  if defined(Q_OS_NETBSD)
-     define QT_STATFSBUF struct statvfs
-     define QT_STATFS    ::statvfs
+#    define QT_STATFSBUF struct statvfs
+#    define QT_STATFS    ::statvfs
 #  else
 #    define QT_STATFSBUF struct statfs
 #    define QT_STATFS    ::statfs
@@ -507,9 +507,15 @@ void QStorageInfoPrivate::retrieveVolumeInfo()
         valid = true;
         ready = true;
 
+#if defined(Q_OS_BSD4) && !defined(Q_OS_NETBSD)
+        bytesTotal = statfs_buf.f_blocks * statfs_buf.f_bsize;
+        bytesFree = statfs_buf.f_bfree * statfs_buf.f_bsize;
+        bytesAvailable = statfs_buf.f_bavail * statfs_buf.f_bsize;
+#else
         bytesTotal = statfs_buf.f_blocks * statfs_buf.f_frsize;
         bytesFree = statfs_buf.f_bfree * statfs_buf.f_frsize;
         bytesAvailable = statfs_buf.f_bavail * statfs_buf.f_frsize;
+#endif
         blockSize = statfs_buf.f_bsize;
 #if defined(Q_OS_ANDROID) || defined (Q_OS_BSD4)
 #if defined(_STATFS_F_FLAGS)
diff --git a/src/corelib/io/qwindowspipereader.cpp b/src/corelib/io/qwindowspipereader.cpp
index a49fcdaf9f..f0d6417483 100644
--- a/src/corelib/io/qwindowspipereader.cpp
+++ b/src/corelib/io/qwindowspipereader.cpp
@@ -186,6 +186,10 @@ void QWindowsPipeReader::notified(quint32 numberOfBytesRead, quint32 errorCode,
     case ERROR_PIPE_NOT_CONNECTED:
         pipeBroken = true;
         break;
+    case ERROR_OPERATION_ABORTED:
+        if (stopped)
+            break;
+        // fall through
     default:
         emit winError(errorCode, QLatin1String("QWindowsPipeReader::notified"));
         pipeBroken = true;
diff --git a/src/corelib/io/qwinoverlappedionotifier.cpp b/src/corelib/io/qwinoverlappedionotifier.cpp
index 083feb4a20..c6ce15c2c9 100644
--- a/src/corelib/io/qwinoverlappedionotifier.cpp
+++ b/src/corelib/io/qwinoverlappedionotifier.cpp
@@ -33,6 +33,7 @@
 
 #include "qwinoverlappedionotifier_p.h"
 #include <qdebug.h>
+#include <qatomic.h>
 #include <qelapsedtimer.h>
 #include <qmutex.h>
 #include <qpointer.h>
@@ -99,6 +100,7 @@ public:
     {
     }
 
+    OVERLAPPED *waitForAnyNotified(int msecs);
     void notify(DWORD numberOfBytes, DWORD errorCode, OVERLAPPED *overlapped);
     OVERLAPPED *_q_notified();
 
@@ -108,6 +110,7 @@ public:
     HANDLE hHandle;
     HANDLE hSemaphore;
     HANDLE hResultsMutex;
+    QAtomicInt waiting;
     QQueue<IOResult> results;
 };
 
@@ -286,28 +289,21 @@ void QWinOverlappedIoNotifier::setEnabled(bool enabled)
         d->iocp->unregisterNotifier(d);
 }
 
-/*!
- * Wait synchronously for any notified signal.
- *
- * The function returns a pointer to the OVERLAPPED object corresponding to the completed I/O
- * operation. In case no I/O operation was completed during the \a msec timeout, this function
- * returns a null pointer.
- */
-OVERLAPPED *QWinOverlappedIoNotifier::waitForAnyNotified(int msecs)
+OVERLAPPED *QWinOverlappedIoNotifierPrivate::waitForAnyNotified(int msecs)
 {
-    Q_D(QWinOverlappedIoNotifier);
-    if (!d->iocp->isRunning()) {
+    if (!iocp->isRunning()) {
         qWarning("Called QWinOverlappedIoNotifier::waitForAnyNotified on inactive notifier.");
         return 0;
     }
 
     if (msecs == 0)
-        d->iocp->drainQueue();
+        iocp->drainQueue();
 
-    switch (WaitForSingleObject(d->hSemaphore, msecs == -1 ? INFINITE : DWORD(msecs))) {
+    const DWORD wfso = WaitForSingleObject(hSemaphore, msecs == -1 ? INFINITE : DWORD(msecs));
+    switch (wfso) {
     case WAIT_OBJECT_0:
-        ReleaseSemaphore(d->hSemaphore, 1, NULL);
-        return d->_q_notified();
+        ReleaseSemaphore(hSemaphore, 1, NULL);
+        return _q_notified();
     case WAIT_TIMEOUT:
         return 0;
     default:
@@ -316,6 +312,39 @@ OVERLAPPED *QWinOverlappedIoNotifier::waitForAnyNotified(int msecs)
     }
 }
 
+class QScopedAtomicIntIncrementor
+{
+public:
+    QScopedAtomicIntIncrementor(QAtomicInt &i)
+        : m_int(i)
+    {
+        ++m_int;
+    }
+
+    ~QScopedAtomicIntIncrementor()
+    {
+        --m_int;
+    }
+
+private:
+    QAtomicInt &m_int;
+};
+
+/*!
+ * Wait synchronously for any notified signal.
+ *
+ * The function returns a pointer to the OVERLAPPED object corresponding to the completed I/O
+ * operation. In case no I/O operation was completed during the \a msec timeout, this function
+ * returns a null pointer.
+ */
+OVERLAPPED *QWinOverlappedIoNotifier::waitForAnyNotified(int msecs)
+{
+    Q_D(QWinOverlappedIoNotifier);
+    QScopedAtomicIntIncrementor saii(d->waiting);
+    OVERLAPPED *result = d->waitForAnyNotified(msecs);
+    return result;
+}
+
 /*!
  * Wait synchronously for the notified signal.
  *
@@ -324,6 +353,8 @@ OVERLAPPED *QWinOverlappedIoNotifier::waitForAnyNotified(int msecs)
  */
 bool QWinOverlappedIoNotifier::waitForNotified(int msecs, OVERLAPPED *overlapped)
 {
+    Q_D(QWinOverlappedIoNotifier);
+    QScopedAtomicIntIncrementor saii(d->waiting);
     int t = msecs;
     QElapsedTimer stopWatch;
     stopWatch.start();
@@ -350,7 +381,8 @@ void QWinOverlappedIoNotifierPrivate::notify(DWORD numberOfBytes, DWORD errorCod
     results.enqueue(IOResult(numberOfBytes, errorCode, overlapped));
     ReleaseMutex(hResultsMutex);
     ReleaseSemaphore(hSemaphore, 1, NULL);
-    emit q->_q_notify();
+    if (!waiting)
+        emit q->_q_notify();
 }
 
 OVERLAPPED *QWinOverlappedIoNotifierPrivate::_q_notified()
diff --git a/src/network/access/qnetworkreplyhttpimpl.cpp b/src/network/access/qnetworkreplyhttpimpl.cpp
index c29b132217..ad8a5321b4 100644
--- a/src/network/access/qnetworkreplyhttpimpl.cpp
+++ b/src/network/access/qnetworkreplyhttpimpl.cpp
@@ -1784,8 +1784,9 @@ void QNetworkReplyHttpImplPrivate::_q_startOperation()
 #endif
     } else {
 #ifndef QT_NO_BEARERMANAGEMENT
-        QObject::connect(session.data(), SIGNAL(stateChanged(QNetworkSession::State)),
-                         q, SLOT(_q_networkSessionStateChanged(QNetworkSession::State)), Qt::QueuedConnection);
+        if (session)
+            QObject::connect(session.data(), SIGNAL(stateChanged(QNetworkSession::State)),
+                             q, SLOT(_q_networkSessionStateChanged(QNetworkSession::State)), Qt::QueuedConnection);
 #endif
     }
 
diff --git a/src/plugins/platforms/android/qandroidplatformservices.cpp b/src/plugins/platforms/android/qandroidplatformservices.cpp
index 2dba6c78e1..412e3e0466 100644
--- a/src/plugins/platforms/android/qandroidplatformservices.cpp
+++ b/src/plugins/platforms/android/qandroidplatformservices.cpp
@@ -33,8 +33,9 @@
 
 #include "qandroidplatformservices.h"
 #include <QUrl>
-#include <QDir>
+#include <QFile>
 #include <QDebug>
+#include <QMimeDatabase>
 #include <QtCore/private/qjni_p.h>
 
 QT_BEGIN_NAMESPACE
@@ -43,13 +44,27 @@ QAndroidPlatformServices::QAndroidPlatformServices()
 {
 }
 
-bool QAndroidPlatformServices::openUrl(const QUrl &url)
+bool QAndroidPlatformServices::openUrl(const QUrl &theUrl)
 {
+    QString mime;
+    QUrl url(theUrl);
+
+    // if the file is local, we need to pass the MIME type, otherwise Android
+    // does not start an Intent to view this file
+    if ((url.scheme().isEmpty() && QFile::exists(url.path())) || url.isLocalFile()) {
+        // a real URL including the scheme is needed, else the Intent can not be started
+        url.setScheme(QLatin1String("file"));
+
+        QMimeDatabase mimeDb;
+        mime = mimeDb.mimeTypeForUrl(url).name();
+    }
+
     QJNIObjectPrivate urlString = QJNIObjectPrivate::fromString(url.toString());
+    QJNIObjectPrivate mimeString = QJNIObjectPrivate::fromString(mime);
     return QJNIObjectPrivate::callStaticMethod<jboolean>(QtAndroid::applicationClass(),
                                                          "openURL",
-                                                         "(Ljava/lang/String;)Z",
-                                                         urlString.object());
+                                                         "(Ljava/lang/String;Ljava/lang/String;)Z",
+                                                         urlString.object(), mimeString.object());
 }
 
 bool QAndroidPlatformServices::openDocument(const QUrl &url)
diff --git a/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm b/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm
index 28f3b2af84..b55393c7dc 100644
--- a/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm
+++ b/src/plugins/platforms/cocoa/qcocoaaccessibilityelement.mm
@@ -56,6 +56,14 @@ static void convertLineOffset(QAccessibleTextInterface *text, int &line, int &of
     do {
         curStart = curEnd;
         text->textAtOffset(curStart, QAccessible::LineBoundary, &curStart, &curEnd);
+        // If the text is empty then we just return
+        if (curStart == -1 || curEnd == -1) {
+            if (start)
+                *start = 0;
+            if (end)
+                *end = 0;
+            return;
+        }
         ++curLine;
         {
             // check for a case where a single word longer than the text edit's width and gets wrapped
diff --git a/src/plugins/platforms/windows/qwindowscontext.cpp b/src/plugins/platforms/windows/qwindowscontext.cpp
index 4d18e7ea58..02accfae01 100644
--- a/src/plugins/platforms/windows/qwindowscontext.cpp
+++ b/src/plugins/platforms/windows/qwindowscontext.cpp
@@ -201,12 +201,14 @@ void QWindowsUser32DLL::init()
 
 bool QWindowsUser32DLL::initTouch()
 {
-    QSystemLibrary library(QStringLiteral("user32"));
-    isTouchWindow = (IsTouchWindow)(library.resolve("IsTouchWindow"));
-    registerTouchWindow = (RegisterTouchWindow)(library.resolve("RegisterTouchWindow"));
-    unregisterTouchWindow = (UnregisterTouchWindow)(library.resolve("UnregisterTouchWindow"));
-    getTouchInputInfo = (GetTouchInputInfo)(library.resolve("GetTouchInputInfo"));
-    closeTouchInputHandle = (CloseTouchInputHandle)(library.resolve("CloseTouchInputHandle"));
+    if (!isTouchWindow && QSysInfo::windowsVersion() >= QSysInfo::WV_WINDOWS7) {
+        QSystemLibrary library(QStringLiteral("user32"));
+        isTouchWindow = (IsTouchWindow)(library.resolve("IsTouchWindow"));
+        registerTouchWindow = (RegisterTouchWindow)(library.resolve("RegisterTouchWindow"));
+        unregisterTouchWindow = (UnregisterTouchWindow)(library.resolve("UnregisterTouchWindow"));
+        getTouchInputInfo = (GetTouchInputInfo)(library.resolve("GetTouchInputInfo"));
+        closeTouchInputHandle = (CloseTouchInputHandle)(library.resolve("CloseTouchInputHandle"));
+    }
     return isTouchWindow && registerTouchWindow && unregisterTouchWindow && getTouchInputInfo && closeTouchInputHandle;
 }
 
@@ -359,6 +361,36 @@ QWindowsContext::~QWindowsContext()
     m_instance = 0;
 }
 
+bool QWindowsContext::initTouch()
+{
+    return initTouch(QWindowsIntegration::instance()->options());
+}
+
+bool QWindowsContext::initTouch(unsigned integrationOptions)
+{
+    if (d->m_systemInfo & QWindowsContext::SI_SupportsTouch)
+        return true;
+
+    QTouchDevice *touchDevice = d->m_mouseHandler.ensureTouchDevice();
+    if (!touchDevice)
+        return false;
+
+#ifndef Q_OS_WINCE
+    if (!QWindowsContext::user32dll.initTouch()) {
+        delete touchDevice;
+        return false;
+    }
+#endif // !Q_OS_WINCE
+
+    if (!(integrationOptions & QWindowsIntegration::DontPassOsMouseEventsSynthesizedFromTouch))
+        touchDevice->setCapabilities(touchDevice->capabilities() | QTouchDevice::MouseEmulation);
+
+    QWindowSystemInterface::registerTouchDevice(touchDevice);
+
+    d->m_systemInfo |= QWindowsContext::SI_SupportsTouch;
+    return true;
+}
+
 void QWindowsContext::setTabletAbsoluteRange(int a)
 {
 #if !defined(QT_NO_TABLETEVENT) && !defined(Q_OS_WINCE)
diff --git a/src/plugins/platforms/windows/qwindowscontext.h b/src/plugins/platforms/windows/qwindowscontext.h
index d2a3481b28..641e3ed41f 100644
--- a/src/plugins/platforms/windows/qwindowscontext.h
+++ b/src/plugins/platforms/windows/qwindowscontext.h
@@ -170,6 +170,9 @@ public:
     explicit QWindowsContext();
     ~QWindowsContext();
 
+    bool initTouch();
+    bool initTouch(unsigned integrationOptions); // For calls from QWindowsIntegration::QWindowsIntegration() only.
+
     int defaultDPI() const;
 
     QString registerWindowClass(const QWindow *w);
diff --git a/src/plugins/platforms/windows/qwindowsintegration.cpp b/src/plugins/platforms/windows/qwindowsintegration.cpp
index bbb1f68a52..b67e0b859f 100644
--- a/src/plugins/platforms/windows/qwindowsintegration.cpp
+++ b/src/plugins/platforms/windows/qwindowsintegration.cpp
@@ -226,17 +226,7 @@ QWindowsIntegrationPrivate::QWindowsIntegrationPrivate(const QStringList &paramL
     qCDebug(lcQpaWindows)
         << __FUNCTION__ << "DpiAwareness=" << dpiAwareness;
 
-    QTouchDevice *touchDevice = m_context.touchDevice();
-    if (touchDevice) {
-#ifdef Q_OS_WINCE
-        touchDevice->setCapabilities(touchDevice->capabilities() | QTouchDevice::MouseEmulation);
-#else
-        if (!(m_options & QWindowsIntegration::DontPassOsMouseEventsSynthesizedFromTouch)) {
-            touchDevice->setCapabilities(touchDevice->capabilities() | QTouchDevice::MouseEmulation);
-        }
-#endif
-        QWindowSystemInterface::registerTouchDevice(touchDevice);
-    }
+    m_context.initTouch(m_options);
 }
 
 QWindowsIntegrationPrivate::~QWindowsIntegrationPrivate()
diff --git a/src/plugins/platforms/windows/qwindowsmousehandler.cpp b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
index 90cb6fe195..e26010b5c4 100644
--- a/src/plugins/platforms/windows/qwindowsmousehandler.cpp
+++ b/src/plugins/platforms/windows/qwindowsmousehandler.cpp
@@ -150,12 +150,19 @@ static inline QTouchDevice *createTouchDevice()
 QWindowsMouseHandler::QWindowsMouseHandler() :
     m_windowUnderMouse(0),
     m_trackedWindow(0),
-    m_touchDevice(createTouchDevice()),
+    m_touchDevice(Q_NULLPTR),
     m_leftButtonDown(false),
     m_previousCaptureWindow(0)
 {
 }
 
+QTouchDevice *QWindowsMouseHandler::ensureTouchDevice()
+{
+    if (!m_touchDevice)
+        m_touchDevice = createTouchDevice();
+    return m_touchDevice;
+}
+
 Qt::MouseButtons QWindowsMouseHandler::queryMouseButtons()
 {
     Qt::MouseButtons result = 0;
@@ -476,7 +483,11 @@ bool QWindowsMouseHandler::translateTouchEvent(QWindow *window, HWND,
     typedef QWindowSystemInterface::TouchPoint QTouchPoint;
     typedef QList<QWindowSystemInterface::TouchPoint> QTouchPointList;
 
-    Q_ASSERT(m_touchDevice);
+    if (!QWindowsContext::instance()->initTouch()) {
+        qWarning("Unable to initialize touch handling.");
+        return true;
+    }
+
     const QScreen *screen = window->screen();
     if (!screen)
         screen = QGuiApplication::primaryScreen();
@@ -492,8 +503,6 @@ bool QWindowsMouseHandler::translateTouchEvent(QWindow *window, HWND,
     touchPoints.reserve(winTouchPointCount);
     Qt::TouchPointStates allStates = 0;
 
-    Q_ASSERT(QWindowsContext::user32dll.getTouchInputInfo);
-
     QWindowsContext::user32dll.getTouchInputInfo((HANDLE) msg.lParam, msg.wParam, winTouchInputs.data(), sizeof(TOUCHINPUT));
     for (int i = 0; i < winTouchPointCount; ++i) {
         const TOUCHINPUT &winTouchInput = winTouchInputs[i];
diff --git a/src/plugins/platforms/windows/qwindowsmousehandler.h b/src/plugins/platforms/windows/qwindowsmousehandler.h
index 61aa8d6084..4b5078567d 100644
--- a/src/plugins/platforms/windows/qwindowsmousehandler.h
+++ b/src/plugins/platforms/windows/qwindowsmousehandler.h
@@ -52,6 +52,7 @@ public:
     QWindowsMouseHandler();
 
     QTouchDevice *touchDevice() const { return m_touchDevice; }
+    QTouchDevice *ensureTouchDevice();
 
     bool translateMouseEvent(QWindow *widget, HWND hwnd,
                              QtWindows::WindowsEventType t, MSG msg,