Tidy nullptr usage

Move away from using 0 as pointer literal.

Done using clang-tidy. This is not complete as
run-clang-tidy can't handle all of qtbase in one go.

Change-Id: I1076a21f32aac0dab078af6f175f7508145eece0
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@qt.io>
Reviewed-by: Lars Knoll <lars.knoll@qt.io>

18 files changed, 116 insertions, 116 deletions

diff --git a/src/gui/image/qbmphandler.cpp b/src/gui/image/qbmphandler.cpp
index 7f8e072322..32b6131309 100644
--- a/src/gui/image/qbmphandler.cpp
+++ b/src/gui/image/qbmphandler.cpp
@@ -414,7 +414,7 @@ static bool read_dib_body(QDataStream &s, const BMP_INFOHDR &bi, qint64 offset,
                                 *p++ = tmp >> 4;
                             }
                             if ((((c & 3) + 1) & 2) == 2)
-                                d->getChar(0);        // align on word boundary
+                                d->getChar(nullptr);        // align on word boundary
                             x += c;
                     }
                 } else {                        // encoded mode
@@ -494,7 +494,7 @@ static bool read_dib_body(QDataStream &s, const BMP_INFOHDR &bi, qint64 offset,
                             if (d->read((char *)p, b) != b)
                                 return false;
                             if ((b & 1) == 1)
-                                d->getChar(0);        // align on word boundary
+                                d->getChar(nullptr);        // align on word boundary
                             x += b;
                             p += b;
                     }
diff --git a/src/gui/image/qicon.cpp b/src/gui/image/qicon.cpp
index 84e387e317..19be066d23 100644
--- a/src/gui/image/qicon.cpp
+++ b/src/gui/image/qicon.cpp
@@ -132,7 +132,7 @@ static void qt_cleanup_icon_cache()
     if Qt::AA_UseHighDpiPixmaps is not set this function
     returns 1.0 to keep non-hihdpi aware code working.
 */
-static qreal qt_effective_device_pixel_ratio(QWindow *window = 0)
+static qreal qt_effective_device_pixel_ratio(QWindow *window = nullptr)
 {
     if (!qApp->testAttribute(Qt::AA_UseHighDpiPixmaps))
         return qreal(1.0);
@@ -228,7 +228,7 @@ static QPixmapIconEngineEntry *bestSizeMatch( const QSize &size, QPixmapIconEngi
 
 QPixmapIconEngineEntry *QPixmapIconEngine::tryMatch(const QSize &size, QIcon::Mode mode, QIcon::State state)
 {
-    QPixmapIconEngineEntry *pe = 0;
+    QPixmapIconEngineEntry *pe = nullptr;
     for (int i = 0; i < pixmaps.count(); ++i)
         if (pixmaps.at(i).mode == mode && pixmaps.at(i).state == state) {
             if (pe)
@@ -674,7 +674,7 @@ QFactoryLoader *qt_iconEngineFactoryLoader()
   Constructs a null icon.
 */
 QIcon::QIcon() noexcept
-    : d(0)
+    : d(nullptr)
 {
 }
 
@@ -682,7 +682,7 @@ QIcon::QIcon() noexcept
   Constructs an icon from a \a pixmap.
  */
 QIcon::QIcon(const QPixmap &pixmap)
-    :d(0)
+    :d(nullptr)
 {
     addPixmap(pixmap);
 }
@@ -723,7 +723,7 @@ QIcon::QIcon(const QIcon &other)
     complete list of the supported file formats.
 */
 QIcon::QIcon(const QString &fileName)
-    : d(0)
+    : d(nullptr)
 {
     addFile(fileName);
 }
@@ -838,7 +838,7 @@ QPixmap QIcon::pixmap(const QSize &size, Mode mode, State state) const
 {
     if (!d)
         return QPixmap();
-    return pixmap(0, size, mode, state);
+    return pixmap(nullptr, size, mode, state);
 }
 
 /*!
@@ -878,7 +878,7 @@ QSize QIcon::actualSize(const QSize &size, Mode mode, State state) const
 {
     if (!d)
         return QSize();
-    return actualSize(0, size, mode, state);
+    return actualSize(nullptr, size, mode, state);
 }
 
 /*!
@@ -1008,7 +1008,7 @@ void QIcon::detach()
         if (d->engine->isNull()) {
             if (!d->ref.deref())
                 delete d;
-            d = 0;
+            d = nullptr;
             return;
         } else if (d->ref.loadRelaxed() != 1) {
             QIconPrivate *x = new QIconPrivate(d->engine->clone());
diff --git a/src/gui/image/qiconloader.cpp b/src/gui/image/qiconloader.cpp
index 27c82bc09f..e67b387981 100644
--- a/src/gui/image/qiconloader.cpp
+++ b/src/gui/image/qiconloader.cpp
@@ -714,7 +714,7 @@ QIconLoaderEngineEntry *QIconLoaderEngine::entryForSize(const QThemeIconInfo &in
 
     // Find the minimum distance icon
     int minimalSize = INT_MAX;
-    QIconLoaderEngineEntry *closestMatch = 0;
+    QIconLoaderEngineEntry *closestMatch = nullptr;
     for (int i = 0; i < numEntries; ++i) {
         QIconLoaderEngineEntry *entry = info.entries.at(i);
         int distance = directorySizeDistance(entry->dir, iconsize, scale);
diff --git a/src/gui/image/qimage.cpp b/src/gui/image/qimage.cpp
index 869e206524..99d64737c5 100644
--- a/src/gui/image/qimage.cpp
+++ b/src/gui/image/qimage.cpp
@@ -73,7 +73,7 @@ QT_BEGIN_NAMESPACE
 
 static inline bool isLocked(QImageData *data)
 {
-    return data != 0 && data->is_locked;
+    return data != nullptr && data->is_locked;
 }
 
 #if defined(Q_CC_DEC) && defined(__alpha) && (__DECCXX_VER-0 >= 50190001)
@@ -99,15 +99,15 @@ static int next_qimage_serial_number()
 }
 
 QImageData::QImageData()
-    : ref(0), width(0), height(0), depth(0), nbytes(0), devicePixelRatio(1.0), data(0),
+    : ref(0), width(0), height(0), depth(0), nbytes(0), devicePixelRatio(1.0), data(nullptr),
       format(QImage::Format_ARGB32), bytes_per_line(0),
       ser_no(next_qimage_serial_number()),
       detach_no(0),
       dpmx(qt_defaultDpiX() * 100 / qreal(2.54)),
       dpmy(qt_defaultDpiY() * 100 / qreal(2.54)),
       offset(0, 0), own_data(true), ro_data(false), has_alpha_clut(false),
-      is_cached(false), is_locked(false), cleanupFunction(0), cleanupInfo(0),
-      paintEngine(0)
+      is_cached(false), is_locked(false), cleanupFunction(nullptr), cleanupInfo(nullptr),
+      paintEngine(nullptr)
 {
 }
 
@@ -170,7 +170,7 @@ QImageData::~QImageData()
     delete paintEngine;
     if (data && own_data)
         free(data);
-    data = 0;
+    data = nullptr;
 }
 
 #if defined(_M_ARM)
@@ -746,7 +746,7 @@ bool QImageData::checkForAlphaPixels() const
 QImage::QImage() noexcept
     : QPaintDevice()
 {
-    d = 0;
+    d = nullptr;
 }
 
 /*!
@@ -955,7 +955,7 @@ QImage::QImage(const uchar *data, int width, int height, int bytesPerLine, Forma
 QImage::QImage(const QString &fileName, const char *format)
     : QPaintDevice()
 {
-    d = 0;
+    d = nullptr;
     load(fileName, format);
 }
 
@@ -981,10 +981,10 @@ extern bool qt_read_xpm_image_or_array(QIODevice *device, const char * const *so
 QImage::QImage(const char * const xpm[])
     : QPaintDevice()
 {
-    d = 0;
+    d = nullptr;
     if (!xpm)
         return;
-    if (!qt_read_xpm_image_or_array(0, xpm, *this))
+    if (!qt_read_xpm_image_or_array(nullptr, xpm, *this))
         // Issue: Warning because the constructor may be ambigious
         qWarning("QImage::QImage(), XPM is not supported");
 }
@@ -1003,7 +1003,7 @@ QImage::QImage(const QImage &image)
     : QPaintDevice()
 {
     if (image.paintingActive() || isLocked(image.d)) {
-        d = 0;
+        d = nullptr;
         image.copy().swap(*this);
     } else {
         d = image.d;
@@ -1593,13 +1593,13 @@ void QImage::setColor(int i, QRgb c)
 uchar *QImage::scanLine(int i)
 {
     if (!d)
-        return 0;
+        return nullptr;
 
     detach();
 
     // In case detach() ran out of memory
     if (!d)
-        return 0;
+        return nullptr;
 
     return d->data + i * d->bytes_per_line;
 }
@@ -1610,7 +1610,7 @@ uchar *QImage::scanLine(int i)
 const uchar *QImage::scanLine(int i) const
 {
     if (!d)
-        return 0;
+        return nullptr;
 
     Q_ASSERT(i >= 0 && i < height());
     return d->data + i * d->bytes_per_line;
@@ -1633,7 +1633,7 @@ const uchar *QImage::scanLine(int i) const
 const uchar *QImage::constScanLine(int i) const
 {
     if (!d)
-        return 0;
+        return nullptr;
 
     Q_ASSERT(i >= 0 && i < height());
     return d->data + i * d->bytes_per_line;
@@ -1653,12 +1653,12 @@ const uchar *QImage::constScanLine(int i) const
 uchar *QImage::bits()
 {
     if (!d)
-        return 0;
+        return nullptr;
     detach();
 
     // In case detach ran out of memory...
     if (!d)
-        return 0;
+        return nullptr;
 
     return d->data;
 }
@@ -1672,7 +1672,7 @@ uchar *QImage::bits()
 */
 const uchar *QImage::bits() const
 {
-    return d ? d->data : 0;
+    return d ? d->data : nullptr;
 }
 
 
@@ -1688,7 +1688,7 @@ const uchar *QImage::bits() const
 */
 const uchar *QImage::constBits() const
 {
-    return d ? d->data : 0;
+    return d ? d->data : nullptr;
 }
 
 /*!
@@ -3027,11 +3027,11 @@ QImage QImage::createHeuristicMask(bool clipTight) const
     while(!done) {
         done = true;
         ypn = m.scanLine(0);
-        ypc = 0;
+        ypc = nullptr;
         for (y = 0; y < h; y++) {
             ypp = ypc;
             ypc = ypn;
-            ypn = (y == h-1) ? 0 : m.scanLine(y+1);
+            ypn = (y == h-1) ? nullptr : m.scanLine(y+1);
             const QRgb *p = (const QRgb *)scanLine(y);
             for (x = 0; x < w; x++) {
                 // slowness here - it's possible to do six of these tests
@@ -3053,11 +3053,11 @@ QImage QImage::createHeuristicMask(bool clipTight) const
 
     if (!clipTight) {
         ypn = m.scanLine(0);
-        ypc = 0;
+        ypc = nullptr;
         for (y = 0; y < h; y++) {
             ypp = ypc;
             ypc = ypn;
-            ypn = (y == h-1) ? 0 : m.scanLine(y+1);
+            ypn = (y == h-1) ? nullptr : m.scanLine(y+1);
             const QRgb *p = (const QRgb *)scanLine(y);
             for (x = 0; x < w; x++) {
                 if ((*p & 0x00ffffff) != background) {
@@ -4122,7 +4122,7 @@ void QImage::setText(const QString &key, const QString &value)
 QPaintEngine *QImage::paintEngine() const
 {
     if (!d)
-        return 0;
+        return nullptr;
 
     if (!d->paintEngine) {
         QPaintDevice *paintDevice = const_cast<QImage *>(this);
diff --git a/src/gui/image/qimage_conversions.cpp b/src/gui/image/qimage_conversions.cpp
index 8f33a13b95..27088698ec 100644
--- a/src/gui/image/qimage_conversions.cpp
+++ b/src/gui/image/qimage_conversions.cpp
@@ -198,7 +198,7 @@ void convert_generic(QImageData *dest, const QImageData *src, Qt::ImageConversio
             store = destLayout->storeFromRGB32;
     }
     QDitherInfo dither;
-    QDitherInfo *ditherPtr = 0;
+    QDitherInfo *ditherPtr = nullptr;
     if ((flags & Qt::PreferDither) && (flags & Qt::Dither_Mask) != Qt::ThresholdDither)
         ditherPtr = &dither;
 
@@ -212,8 +212,8 @@ void convert_generic(QImageData *dest, const QImageData *src, Qt::ImageConversio
                 buffer = reinterpret_cast<uint *>(destData) + x;
             else
                 l = qMin(l, BufferSize);
-            const uint *ptr = fetch(buffer, srcData, x, l, 0, ditherPtr);
-            store(destData, ptr, x, l, 0, ditherPtr);
+            const uint *ptr = fetch(buffer, srcData, x, l, nullptr, ditherPtr);
+            store(destData, ptr, x, l, nullptr, ditherPtr);
             x += l;
         }
         srcData += src->bytes_per_line;
@@ -314,7 +314,7 @@ bool convert_generic_inplace(QImageData *data, QImage::Format dst_format, Qt::Im
             store = destLayout->storeFromRGB32;
     }
     QDitherInfo dither;
-    QDitherInfo *ditherPtr = 0;
+    QDitherInfo *ditherPtr = nullptr;
     if ((flags & Qt::PreferDither) && (flags & Qt::Dither_Mask) != Qt::ThresholdDither)
         ditherPtr = &dither;
 
diff --git a/src/gui/image/qimageiohandler.cpp b/src/gui/image/qimageiohandler.cpp
index a4f927a462..0c9083a16e 100644
--- a/src/gui/image/qimageiohandler.cpp
+++ b/src/gui/image/qimageiohandler.cpp
@@ -288,7 +288,7 @@ public:
 
 QImageIOHandlerPrivate::QImageIOHandlerPrivate(QImageIOHandler *q)
 {
-    device = 0;
+    device = nullptr;
     q_ptr = q;
 }
 
diff --git a/src/gui/image/qimagereader.cpp b/src/gui/image/qimagereader.cpp
index dff24b449a..5e3b608d20 100644
--- a/src/gui/image/qimagereader.cpp
+++ b/src/gui/image/qimagereader.cpp
@@ -179,10 +179,10 @@ static QImageIOHandler *createReadHandlerHelper(QIODevice *device,
                                                 bool ignoresFormatAndExtension)
 {
     if (!autoDetectImageFormat && format.isEmpty())
-        return 0;
+        return nullptr;
 
     QByteArray form = format.toLower();
-    QImageIOHandler *handler = 0;
+    QImageIOHandler *handler = nullptr;
     QByteArray suffix;
 
 #ifndef QT_NO_IMAGEFORMATPLUGIN
@@ -450,7 +450,7 @@ static QImageIOHandler *createReadHandlerHelper(QIODevice *device,
         qDebug("QImageReader::createReadHandler: no handlers found. giving up.");
 #endif
         // no handler: give up.
-        return 0;
+        return nullptr;
     }
 
     handler->setDevice(device);
@@ -500,9 +500,9 @@ public:
 QImageReaderPrivate::QImageReaderPrivate(QImageReader *qq)
     : autoDetectImageFormat(true), ignoresFormatAndExtension(false)
 {
-    device = 0;
+    device = nullptr;
     deleteDevice = false;
-    handler = 0;
+    handler = nullptr;
     quality = -1;
     imageReaderError = QImageReader::UnknownError;
     autoTransform = UsePluginDefault;
@@ -571,7 +571,7 @@ bool QImageReaderPrivate::initHandler()
     }
 
     // assign a handler
-    if (!handler && (handler = createReadHandlerHelper(device, format, autoDetectImageFormat, ignoresFormatAndExtension)) == 0) {
+    if (!handler && (handler = createReadHandlerHelper(device, format, autoDetectImageFormat, ignoresFormatAndExtension)) == nullptr) {
         imageReaderError = QImageReader::UnsupportedFormatError;
         errorString = QImageReader::tr("Unsupported image format");
         return false;
diff --git a/src/gui/image/qimagereaderwriterhelpers.cpp b/src/gui/image/qimagereaderwriterhelpers.cpp
index a5b7fb6449..dd56d887a7 100644
--- a/src/gui/image/qimagereaderwriterhelpers.cpp
+++ b/src/gui/image/qimagereaderwriterhelpers.cpp
@@ -63,7 +63,7 @@ static void appendImagePluginFormats(QFactoryLoader *loader,
     const PluginKeyMap keyMap = loader->keyMap();
     const PluginKeyMapConstIterator cend = keyMap.constEnd();
     int i = -1;
-    QImageIOPlugin *plugin = 0;
+    QImageIOPlugin *plugin = nullptr;
     result->reserve(result->size() + keyMap.size());
     for (PluginKeyMapConstIterator it = keyMap.constBegin(); it != cend; ++it) {
         if (it.key() != i) {
@@ -71,7 +71,7 @@ static void appendImagePluginFormats(QFactoryLoader *loader,
             plugin = qobject_cast<QImageIOPlugin *>(loader->instance(i));
         }
         const QByteArray key = it.value().toLatin1();
-        if (plugin && (plugin->capabilities(0, key) & cap) != 0)
+        if (plugin && (plugin->capabilities(nullptr, key) & cap) != 0)
             result->append(key);
     }
 }
@@ -92,7 +92,7 @@ static void appendImagePluginMimeTypes(QFactoryLoader *loader,
         const int keyCount = keys.size();
         for (int k = 0; k < keyCount; ++k) {
             const QByteArray key = keys.at(k).toString().toLatin1();
-            if (plugin && (plugin->capabilities(0, key) & cap) != 0) {
+            if (plugin && (plugin->capabilities(nullptr, key) & cap) != 0) {
                 result->append(mimeTypes.at(k).toString().toLatin1());
                 if (resultKeys)
                     resultKeys->append(key);
diff --git a/src/gui/image/qimagewriter.cpp b/src/gui/image/qimagewriter.cpp
index ec66588ddf..9dcc955fe2 100644
--- a/src/gui/image/qimagewriter.cpp
+++ b/src/gui/image/qimagewriter.cpp
@@ -139,7 +139,7 @@ static QImageIOHandler *createWriteHandlerHelper(QIODevice *device,
 {
     QByteArray form = format.toLower();
     QByteArray suffix;
-    QImageIOHandler *handler = 0;
+    QImageIOHandler *handler = nullptr;
 
 #ifndef QT_NO_IMAGEFORMATPLUGIN
     typedef QMultiMap<int, QString> PluginKeyMap;
@@ -226,7 +226,7 @@ static QImageIOHandler *createWriteHandlerHelper(QIODevice *device,
 #endif // QT_NO_IMAGEFORMATPLUGIN
 
     if (!handler)
-        return 0;
+        return nullptr;
 
     handler->setDevice(device);
     if (!testFormat.isEmpty())
@@ -270,9 +270,9 @@ public:
 */
 QImageWriterPrivate::QImageWriterPrivate(QImageWriter *qq)
 {
-    device = 0;
+    device = nullptr;
     deleteDevice = false;
-    handler = 0;
+    handler = nullptr;
     quality = -1;
     compression = -1;
     gamma = 0.0;
@@ -304,7 +304,7 @@ bool QImageWriterPrivate::canWriteHelper()
         errorString = QImageWriter::tr("Device not writable");
         return false;
     }
-    if (!handler && (handler = createWriteHandlerHelper(device, format)) == 0) {
+    if (!handler && (handler = createWriteHandlerHelper(device, format)) == nullptr) {
         imageWriterError = QImageWriter::UnsupportedFormatError;
         errorString = QImageWriter::tr("Unsupported image format");
         return false;
@@ -403,7 +403,7 @@ void QImageWriter::setDevice(QIODevice *device)
     d->device = device;
     d->deleteDevice = false;
     delete d->handler;
-    d->handler = 0;
+    d->handler = nullptr;
 }
 
 /*!
@@ -823,7 +823,7 @@ QString QImageWriter::errorString() const
 */
 bool QImageWriter::supportsOption(QImageIOHandler::ImageOption option) const
 {
-    if (!d->handler && (d->handler = createWriteHandlerHelper(d->device, d->format)) == 0) {
+    if (!d->handler && (d->handler = createWriteHandlerHelper(d->device, d->format)) == nullptr) {
         d->imageWriterError = QImageWriter::UnsupportedFormatError;
         d->errorString = QImageWriter::tr("Unsupported image format");
         return false;
diff --git a/src/gui/image/qmovie.cpp b/src/gui/image/qmovie.cpp
index 25fce050a1..79019d0fdf 100644
--- a/src/gui/image/qmovie.cpp
+++ b/src/gui/image/qmovie.cpp
@@ -272,7 +272,7 @@ public:
 /*! \internal
  */
 QMoviePrivate::QMoviePrivate(QMovie *qq)
-    : reader(0), speed(100), movieState(QMovie::NotRunning),
+    : reader(nullptr), speed(100), movieState(QMovie::NotRunning),
       currentFrameNumber(-1), nextFrameNumber(0), greatestFrameNumber(-1),
       nextDelay(0), playCounter(-1),
       cacheMode(QMovie::CacheNone), haveReadAll(false), isFirstIteration(true)
diff --git a/src/gui/image/qpaintengine_pic.cpp b/src/gui/image/qpaintengine_pic.cpp
index 6a87a01a87..e89cac452a 100644
--- a/src/gui/image/qpaintengine_pic.cpp
+++ b/src/gui/image/qpaintengine_pic.cpp
@@ -73,14 +73,14 @@ QPicturePaintEngine::QPicturePaintEngine()
     : QPaintEngine(*(new QPicturePaintEnginePrivate), AllFeatures)
 {
     Q_D(QPicturePaintEngine);
-    d->pt = 0;
+    d->pt = nullptr;
 }
 
 QPicturePaintEngine::QPicturePaintEngine(QPaintEnginePrivate &dptr)
     : QPaintEngine(dptr, AllFeatures)
 {
     Q_D(QPicturePaintEngine);
-    d->pt = 0;
+    d->pt = nullptr;
 }
 
 QPicturePaintEngine::~QPicturePaintEngine()
@@ -484,7 +484,7 @@ void QPicturePaintEngine::drawTextItem(const QPointF &p , const QTextItem &ti)
 #endif
 
     const QTextItemInt &si = static_cast<const QTextItemInt &>(ti);
-    if (si.chars == 0)
+    if (si.chars == nullptr)
         QPaintEngine::drawTextItem(p, ti); // Draw as path
 
     if (d->pic_d->formatMajor >= 9) {
diff --git a/src/gui/image/qpicture.cpp b/src/gui/image/qpicture.cpp
index 978a07b9f9..3a32cc7f15 100644
--- a/src/gui/image/qpicture.cpp
+++ b/src/gui/image/qpicture.cpp
@@ -458,7 +458,7 @@ public:
     QFakeDevice() { dpi_x = qt_defaultDpiX(); dpi_y = qt_defaultDpiY(); }
     void setDpiX(int dpi) { dpi_x = dpi; }
     void setDpiY(int dpi) { dpi_y = dpi; }
-    QPaintEngine *paintEngine() const override { return 0; }
+    QPaintEngine *paintEngine() const override { return nullptr; }
     int metric(PaintDeviceMetric m) const override
     {
         switch(m) {
@@ -709,11 +709,11 @@ bool QPicture::exec(QPainter *painter, QDataStream &s, int nrecords)
 
                 QFontMetrics fm(fnt);
                 QPointF pt(p.x(), p.y() - fm.ascent());
-                qt_format_text(fnt, QRectF(pt, size), flags, /*opt*/0,
-                               str, /*brect=*/0, /*tabstops=*/0, /*...*/0, /*tabarraylen=*/0, painter);
+                qt_format_text(fnt, QRectF(pt, size), flags, /*opt*/nullptr,
+                               str, /*brect=*/nullptr, /*tabstops=*/0, /*...*/nullptr, /*tabarraylen=*/0, painter);
             } else {
-                qt_format_text(font, QRectF(p, QSizeF(1, 1)), Qt::TextSingleLine | Qt::TextDontClip, /*opt*/0,
-                               str, /*brect=*/0, /*tabstops=*/0, /*...*/0, /*tabarraylen=*/0, painter);
+                qt_format_text(font, QRectF(p, QSizeF(1, 1)), Qt::TextSingleLine | Qt::TextDontClip, /*opt*/nullptr,
+                               str, /*brect=*/nullptr, /*tabstops=*/0, /*...*/nullptr, /*tabarraylen=*/0, painter);
             }
 
             break;
@@ -1369,11 +1369,11 @@ QPictureIO::QPictureIO(const QString &fileName, const char* format)
 void QPictureIO::init()
 {
     d = new QPictureIOData();
-    d->parameters = 0;
+    d->parameters = nullptr;
     d->quality = -1; // default quality of the current format
     d->gamma=0.0f;
     d->iostat = 0;
-    d->iodev  = 0;
+    d->iodev  = nullptr;
 }
 
 /*!
@@ -1467,7 +1467,7 @@ static QPictureHandler *get_picture_handler(const char *format)
                 return list->at(i);
         }
     }
-    return 0;                                        // no such handler
+    return nullptr;                                        // no such handler
 }
 
 
@@ -1887,7 +1887,7 @@ bool QPictureIO::read()
         if (picture_format.isEmpty()) {
             if (file.isOpen()) {                        // unknown format
                 file.close();
-                d->iodev = 0;
+                d->iodev = nullptr;
             }
             return false;
         }
@@ -1913,7 +1913,7 @@ bool QPictureIO::read()
 
     if (file.isOpen()) {                        // picture was read using file
         file.close();
-        d->iodev = 0;
+        d->iodev = nullptr;
     }
     return d->iostat == 0;                                // picture successfully read?
 }
@@ -1957,7 +1957,7 @@ bool QPictureIO::write()
     (*h->write_picture)(this);
     if (file.isOpen()) {                        // picture was written using file
         file.close();
-        d->iodev = 0;
+        d->iodev = nullptr;
     }
     return d->iostat == 0;                                // picture successfully written?
 }
diff --git a/src/gui/image/qpixmap.cpp b/src/gui/image/qpixmap.cpp
index b6e41f16a5..3fce64cb20 100644
--- a/src/gui/image/qpixmap.cpp
+++ b/src/gui/image/qpixmap.cpp
@@ -94,7 +94,7 @@ void QPixmap::doInit(int w, int h, int type)
     if ((w > 0 && h > 0) || type == QPlatformPixmap::BitmapType)
         data = QPlatformPixmap::create(w, h, (QPlatformPixmap::PixelType) type);
     else
-        data = 0;
+        data = nullptr;
 }
 
 /*!
@@ -780,7 +780,7 @@ bool QPixmap::load(const QString &fileName, const char *format, Qt::ImageConvers
 
 bool QPixmap::loadFromData(const uchar *buf, uint len, const char *format, Qt::ImageConversionFlags flags)
 {
-    if (len == 0 || buf == 0) {
+    if (len == 0 || buf == nullptr) {
         data.reset();
         return false;
     }
@@ -1455,7 +1455,7 @@ int QPixmap::metric(PaintDeviceMetric metric) const
 */
 QPaintEngine *QPixmap::paintEngine() const
 {
-    return data ? data->paintEngine() : 0;
+    return data ? data->paintEngine() : nullptr;
 }
 
 /*!
diff --git a/src/gui/image/qpixmap_blitter.cpp b/src/gui/image/qpixmap_blitter.cpp
index 649a25250c..aeed1e3b34 100644
--- a/src/gui/image/qpixmap_blitter.cpp
+++ b/src/gui/image/qpixmap_blitter.cpp
@@ -92,8 +92,8 @@ void QBlittablePlatformPixmap::setBlittable(QBlittable *blittable)
 
 void QBlittablePlatformPixmap::resize(int width, int height)
 {
-    m_blittable.reset(0);
-    m_engine.reset(0);
+    m_blittable.reset(nullptr);
+    m_engine.reset(nullptr);
     d = QGuiApplication::primaryScreen()->depth();
     w = width;
     h = height;
@@ -145,8 +145,8 @@ void QBlittablePlatformPixmap::fill(const QColor &color)
         // if we could just change the format, e.g. when going from
         // RGB32 -> ARGB8888.
         if (color.alpha() != 255 && !hasAlphaChannel()) {
-            m_blittable.reset(0);
-            m_engine.reset(0);
+            m_blittable.reset(nullptr);
+            m_engine.reset(nullptr);
             m_alpha = true;
         }
 
diff --git a/src/gui/image/qpixmapcache.cpp b/src/gui/image/qpixmapcache.cpp
index 483d6d79a2..9709df9e0c 100644
--- a/src/gui/image/qpixmapcache.cpp
+++ b/src/gui/image/qpixmapcache.cpp
@@ -126,7 +126,7 @@ static inline bool qt_pixmapcache_thread_test()
 /*!
     Constructs an empty Key object.
 */
-QPixmapCache::Key::Key() : d(0)
+QPixmapCache::Key::Key() : d(nullptr)
 {
 }
 
@@ -259,9 +259,9 @@ uint qHash(const QPixmapCache::Key &k)
 }
 
 QPMCache::QPMCache()
-    : QObject(0),
+    : QObject(nullptr),
       QCache<QPixmapCache::Key, QPixmapCacheEntry>(cache_limit_default),
-      keyArray(0), theid(0), ps(0), keyArraySize(0), freeKey(0), t(false)
+      keyArray(nullptr), theid(0), ps(0), keyArraySize(0), freeKey(0), t(false)
 {
 }
 QPMCache::~QPMCache()
@@ -325,7 +325,7 @@ QPixmap *QPMCache::object(const QString &key) const
     QPixmapCache::Key cacheKey = cacheKeys.value(key);
     if (!cacheKey.d || !cacheKey.d->isValid) {
         const_cast<QPMCache *>(this)->cacheKeys.remove(key);
-        return 0;
+        return nullptr;
     }
     QPixmap *ptr = QCache<QPixmapCache::Key, QPixmapCacheEntry>::object(cacheKey);
      //We didn't find the pixmap in the cache, the key is not valid anymore
@@ -453,7 +453,7 @@ void QPMCache::releaseKey(const QPixmapCache::Key &key)
 void QPMCache::clear()
 {
     free(keyArray);
-    keyArray = 0;
+    keyArray = nullptr;
     freeKey = 0;
     keyArraySize = 0;
     //Mark all keys as invalid
@@ -539,7 +539,7 @@ bool QPixmapCache::find(const QString &key, QPixmap *pixmap)
     QPixmap *ptr = pm_cache()->object(key);
     if (ptr && pixmap)
         *pixmap = *ptr;
-    return ptr != 0;
+    return ptr != nullptr;
 }
 
 /*!
@@ -561,7 +561,7 @@ bool QPixmapCache::find(const Key &key, QPixmap *pixmap)
     QPixmap *ptr = pm_cache()->object(key);
     if (ptr && pixmap)
         *pixmap = *ptr;
-    return ptr != 0;
+    return ptr != nullptr;
 }
 
 /*!
diff --git a/src/gui/image/qplatformpixmap.cpp b/src/gui/image/qplatformpixmap.cpp
index a2e01147c4..493f55514e 100644
--- a/src/gui/image/qplatformpixmap.cpp
+++ b/src/gui/image/qplatformpixmap.cpp
@@ -266,7 +266,7 @@ QImage QPlatformPixmap::toImage(const QRect &rect) const
 
 QImage* QPlatformPixmap::buffer()
 {
-    return 0;
+    return nullptr;
 }
 
 
diff --git a/src/gui/image/qpnghandler.cpp b/src/gui/image/qpnghandler.cpp
index d6caf6773a..251f09fe52 100644
--- a/src/gui/image/qpnghandler.cpp
+++ b/src/gui/image/qpnghandler.cpp
@@ -109,7 +109,7 @@ public:
     };
 
     QPngHandlerPrivate(QPngHandler *qq)
-        : gamma(0.0), fileGamma(0.0), quality(50), compression(50), colorSpaceState(Undefined), png_ptr(0), info_ptr(0), end_info(0), state(Ready), q(qq)
+        : gamma(0.0), fileGamma(0.0), quality(50), compression(50), colorSpaceState(Undefined), png_ptr(nullptr), info_ptr(nullptr), end_info(nullptr), state(Ready), q(qq)
     { }
 
     float gamma;
@@ -134,18 +134,18 @@ public:
 
     struct AllocatedMemoryPointers {
         AllocatedMemoryPointers()
-            : row_pointers(0), accRow(0), inRow(0), outRow(0)
+            : row_pointers(nullptr), accRow(nullptr), inRow(nullptr), outRow(nullptr)
         { }
         void deallocate()
         {
             delete [] row_pointers;
-            row_pointers = 0;
+            row_pointers = nullptr;
             delete [] accRow;
-            accRow = 0;
+            accRow = nullptr;
             delete [] inRow;
-            inRow = 0;
+            inRow = nullptr;
             delete [] outRow;
-            outRow = 0;
+            outRow = nullptr;
         }
 
         png_byte **row_pointers;
@@ -245,13 +245,13 @@ void setup_qt(QImage& image, png_structp png_ptr, png_infop info_ptr, QSize scal
     png_uint_32 height = 0;
     int bit_depth = 0;
     int color_type = 0;
-    png_bytep trans_alpha = 0;
-    png_color_16p trans_color_p = 0;
+    png_bytep trans_alpha = nullptr;
+    png_color_16p trans_color_p = nullptr;
     int num_trans;
-    png_colorp palette = 0;
+    png_colorp palette = nullptr;
     int num_palette;
     int interlace_method = PNG_INTERLACE_LAST;
-    png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_method, 0, 0);
+    png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, &interlace_method, nullptr, nullptr);
     png_set_interlace_handling(png_ptr);
 
     if (color_type == PNG_COLOR_TYPE_GRAY) {
@@ -343,7 +343,7 @@ void setup_qt(QImage& image, png_structp png_ptr, png_infop info_ptr, QSize scal
         if (bit_depth != 1)
             png_set_packing(png_ptr);
         png_read_update_info(png_ptr, info_ptr);
-        png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, 0, 0, 0);
+        png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, nullptr, nullptr, nullptr);
         QImage::Format format = bit_depth == 1 ? QImage::Format_Mono : QImage::Format_Indexed8;
         if (image.size() != QSize(width, height) || image.format() != format) {
             image = QImage(width, height, format);
@@ -452,7 +452,7 @@ static void read_image_scaled(QImage *outImage, png_structp png_ptr, png_infop i
     int bit_depth = 0;
     int color_type = 0;
     int unit_type = PNG_OFFSET_PIXEL;
-    png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, 0, 0, 0);
+    png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, nullptr, nullptr, nullptr);
     png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y, &unit_type);
     uchar *data = outImage->bits();
     int bpl = outImage->bytesPerLine();
@@ -478,7 +478,7 @@ static void read_image_scaled(QImage *outImage, png_structp png_ptr, png_infop i
             amp.accRow[i] = rval*amp.inRow[i];
         // Accumulate the next input rows
         for (rval = iysz-rval; rval > 0; rval-=oysz) {
-            png_read_row(png_ptr, amp.inRow, NULL);
+            png_read_row(png_ptr, amp.inRow, nullptr);
             quint32 fact = qMin(oysz, quint32(rval));
             for (quint32 i=0; i < ibw; i++)
                 amp.accRow[i] += fact*amp.inRow[i];
@@ -558,11 +558,11 @@ void QPngHandlerPrivate::readPngTexts(png_info *info)
 bool QPngHandlerPrivate::readPngHeader()
 {
     state = Error;
-    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,0,0,0);
+    png_ptr = png_create_read_struct(PNG_LIBPNG_VER_STRING,nullptr,nullptr,nullptr);
     if (!png_ptr)
         return false;
 
-    png_set_error_fn(png_ptr, 0, 0, qt_png_warning);
+    png_set_error_fn(png_ptr, nullptr, nullptr, qt_png_warning);
 
 #if defined(PNG_SET_OPTION_SUPPORTED) && defined(PNG_MAXIMUM_INFLATE_WINDOW)
     // Trade off a little bit of memory for better compatibility with existing images
@@ -572,21 +572,21 @@ bool QPngHandlerPrivate::readPngHeader()
 
     info_ptr = png_create_info_struct(png_ptr);
     if (!info_ptr) {
-        png_destroy_read_struct(&png_ptr, 0, 0);
-        png_ptr = 0;
+        png_destroy_read_struct(&png_ptr, nullptr, nullptr);
+        png_ptr = nullptr;
         return false;
     }
 
     end_info = png_create_info_struct(png_ptr);
     if (!end_info) {
-        png_destroy_read_struct(&png_ptr, &info_ptr, 0);
-        png_ptr = 0;
+        png_destroy_read_struct(&png_ptr, &info_ptr, nullptr);
+        png_ptr = nullptr;
         return false;
     }
 
     if (setjmp(png_jmpbuf(png_ptr))) {
         png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
-        png_ptr = 0;
+        png_ptr = nullptr;
         return false;
     }
 
@@ -670,7 +670,7 @@ bool QPngHandlerPrivate::readPngImage(QImage *outImage)
 
     if (setjmp(png_jmpbuf(png_ptr))) {
         png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
-        png_ptr = 0;
+        png_ptr = nullptr;
         amp.deallocate();
         state = Error;
         return false;
@@ -689,7 +689,7 @@ bool QPngHandlerPrivate::readPngImage(QImage *outImage)
 
     if (outImage->isNull()) {
         png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
-        png_ptr = 0;
+        png_ptr = nullptr;
         amp.deallocate();
         state = Error;
         return false;
@@ -706,7 +706,7 @@ bool QPngHandlerPrivate::readPngImage(QImage *outImage)
         int bit_depth = 0;
         int color_type = 0;
         int unit_type = PNG_OFFSET_PIXEL;
-        png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, 0, 0, 0);
+        png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, nullptr, nullptr, nullptr);
         png_get_oFFs(png_ptr, info_ptr, &offset_x, &offset_y, &unit_type);
         uchar *data = outImage->bits();
         int bpl = outImage->bytesPerLine();
@@ -747,7 +747,7 @@ bool QPngHandlerPrivate::readPngImage(QImage *outImage)
         outImage->setText(readTexts.at(i), readTexts.at(i+1));
 
     png_destroy_read_struct(&png_ptr, &info_ptr, &end_info);
-    png_ptr = 0;
+    png_ptr = nullptr;
     amp.deallocate();
     state = Ready;
 
@@ -767,7 +767,7 @@ QImage::Format QPngHandlerPrivate::readImageFormat()
         int bit_depth = 0, color_type = 0;
         png_colorp palette;
         int num_palette;
-        png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, 0, 0, 0);
+        png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type, nullptr, nullptr, nullptr);
         if (color_type == PNG_COLOR_TYPE_GRAY) {
             // Black & White or grayscale
             if (bit_depth == 1 && png_get_channels(png_ptr, info_ptr) == 1) {
@@ -910,16 +910,16 @@ bool QPNGImageWriter::writeImage(const QImage& image, int compression_in, const
     png_structp png_ptr;
     png_infop info_ptr;
 
-    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,0,0,0);
+    png_ptr = png_create_write_struct(PNG_LIBPNG_VER_STRING,nullptr,nullptr,nullptr);
     if (!png_ptr) {
         return false;
     }
 
-    png_set_error_fn(png_ptr, 0, 0, qt_png_warning);
+    png_set_error_fn(png_ptr, nullptr, nullptr, qt_png_warning);
 
     info_ptr = png_create_info_struct(png_ptr);
     if (!info_ptr) {
-        png_destroy_write_struct(&png_ptr, 0);
+        png_destroy_write_struct(&png_ptr, nullptr);
         return false;
     }
 
@@ -1022,7 +1022,7 @@ bool QPNGImageWriter::writeImage(const QImage& image, int compression_in, const
         png_set_PLTE(png_ptr, info_ptr, palette, num_palette);
 
         if (num_trans) {
-            png_set_tRNS(png_ptr, info_ptr, trans, num_trans, 0);
+            png_set_tRNS(png_ptr, info_ptr, trans, num_trans, nullptr);
         }
     }
 
diff --git a/src/gui/image/qxpmhandler.cpp b/src/gui/image/qxpmhandler.cpp
index cf105b250a..f9424b62bb 100644
--- a/src/gui/image/qxpmhandler.cpp
+++ b/src/gui/image/qxpmhandler.cpp
@@ -1175,7 +1175,7 @@ QXpmHandler::QXpmHandler()
 bool QXpmHandler::readHeader()
 {
     state = Error;
-    if (!read_xpm_header(device(), 0, index, buffer, &cpp, &ncols, &width, &height))
+    if (!read_xpm_header(device(), nullptr, index, buffer, &cpp, &ncols, &width, &height))
         return false;
     state = ReadHeader;
     return true;
@@ -1191,7 +1191,7 @@ bool QXpmHandler::readImage(QImage *image)
         return false;
     }
 
-    if (!read_xpm_body(device(), 0, index, buffer, cpp, ncols, width, height, *image)) {
+    if (!read_xpm_body(device(), nullptr, index, buffer, cpp, ncols, width, height, *image)) {
         state = Error;
         return false;
     }