3 files changed, 46 insertions, 13 deletions

diff --git a/src/gui/image/qicon.cpp b/src/gui/image/qicon.cpp
index ac1d303..bf6eb8d 100644
--- a/src/gui/image/qicon.cpp
+++ b/src/gui/image/qicon.cpp
@@ -104,6 +104,15 @@ QT_BEGIN_NAMESPACE
 
 static QBasicAtomicInt serialNumCounter = Q_BASIC_ATOMIC_INITIALIZER(1);
 
+static void qt_cleanup_icon_cache();
+typedef QCache<QString, QIcon> IconCache;
+Q_GLOBAL_STATIC_WITH_INITIALIZER(IconCache, qtIconCache, qAddPostRoutine(qt_cleanup_icon_cache))
+
+static void qt_cleanup_icon_cache()
+{
+    qtIconCache()->clear();
+}
+
 QIconPrivate::QIconPrivate()
     : engine(0), ref(1),
     serialNum(serialNumCounter.fetchAndAddRelaxed(1)),
@@ -963,15 +972,13 @@ QString QIcon::themeName()
 */
 QIcon QIcon::fromTheme(const QString &name, const QIcon &fallback)
 {
-    static QCache <QString, QIcon> iconCache;
-
     QIcon icon;
 
-    if (iconCache.contains(name)) {
-        icon = *iconCache.object(name);
+    if (qtIconCache()->contains(name)) {
+        icon = *qtIconCache()->object(name);
     } else {
         QIcon *cachedIcon  = new QIcon(new QIconLoaderEngine(name));
-        iconCache.insert(name, cachedIcon);
+        qtIconCache()->insert(name, cachedIcon);
         icon = *cachedIcon;
     }
 
diff --git a/src/gui/image/qimagereader.cpp b/src/gui/image/qimagereader.cpp
index c9e015c..9320cfc 100644
--- a/src/gui/image/qimagereader.cpp
+++ b/src/gui/image/qimagereader.cpp
@@ -263,25 +263,37 @@ static QImageIOHandler *createReadHandlerHelper(QIODevice *device,
             device->seek(pos);
     }
 
-    if (!handler && !testFormat.isEmpty() && autoDetectImageFormat && !ignoresFormatAndExtension) {
+    if (!handler && !testFormat.isEmpty() && !ignoresFormatAndExtension) {
         // check if any plugin supports the format (they are not allowed to
         // read from the device yet).
         const qint64 pos = device ? device->pos() : 0;
-        for (int i = 0; i < keys.size(); ++i) {
-            if (i != suffixPluginIndex) {
-                QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(l->instance(keys.at(i)));
-                if (plugin && plugin->capabilities(device, testFormat) & QImageIOPlugin::CanRead) {
+
+        if (autoDetectImageFormat) {
+            for (int i = 0; i < keys.size(); ++i) {
+                if (i != suffixPluginIndex) {
+                    QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(l->instance(keys.at(i)));
+                    if (plugin && plugin->capabilities(device, testFormat) & QImageIOPlugin::CanRead) {
 #ifdef QIMAGEREADER_DEBUG
-                    qDebug() << "QImageReader::createReadHandler: the" << keys.at(i) << "plugin can read this format";
+                        qDebug() << "QImageReader::createReadHandler: the" << keys.at(i) << "plugin can read this format";
 #endif
-                    handler = plugin->create(device, testFormat);
-                    break;
+                        handler = plugin->create(device, testFormat);
+                        break;
+                    }
                 }
             }
+        } else {
+            QImageIOPlugin *plugin = qobject_cast<QImageIOPlugin *>(l->instance(QLatin1String(testFormat)));
+            if (plugin && plugin->capabilities(device, testFormat) & QImageIOPlugin::CanRead) {
+#ifdef QIMAGEREADER_DEBUG
+                qDebug() << "QImageReader::createReadHandler: the" << testFormat << "plugin can read this format";
+#endif
+                handler = plugin->create(device, testFormat);
+            }
         }
         if (device && !device->isSequential())
             device->seek(pos);
     }
+
 #endif // QT_NO_LIBRARY
 
     // if we don't have a handler yet, check if we have built-in support for
diff --git a/src/gui/image/qpixmapfilter.cpp b/src/gui/image/qpixmapfilter.cpp
index 37a6a18..7cf942c 100644
--- a/src/gui/image/qpixmapfilter.cpp
+++ b/src/gui/image/qpixmapfilter.cpp
@@ -422,6 +422,9 @@ void QPixmapConvolutionFilter::draw(QPainter *painter, const QPointF &p, const Q
     if(d->kernelWidth<=0 || d->kernelHeight <= 0)
         return;
 
+    if (src.isNull())
+        return;
+
     QPixmapFilter *filter = painter->paintEngine() && painter->paintEngine()->isExtended() ?
         static_cast<QPaintEngineEx *>(painter->paintEngine())->pixmapFilter(type(), this) : 0;
     QPixmapConvolutionFilter *convolutionFilter = static_cast<QPixmapConvolutionFilter*>(filter);
@@ -902,6 +905,9 @@ void QPixmapBlurFilter::draw(QPainter *painter, const QPointF &p, const QPixmap
     if (!painter->isActive())
         return;
 
+    if (src.isNull())
+        return;
+
     QRectF srcRect = rect;
     if (srcRect.isNull())
         srcRect = src.rect();
@@ -1082,6 +1088,10 @@ void QPixmapColorizeFilter::setStrength(qreal strength)
 void QPixmapColorizeFilter::draw(QPainter *painter, const QPointF &dest, const QPixmap &src, const QRectF &srcRect) const
 {
     Q_D(const QPixmapColorizeFilter);
+
+    if (src.isNull())
+        return;
+
     QPixmapFilter *filter = painter->paintEngine() && painter->paintEngine()->isExtended() ?
         static_cast<QPaintEngineEx *>(painter->paintEngine())->pixmapFilter(type(), this) : 0;
     QPixmapColorizeFilter *colorizeFilter = static_cast<QPixmapColorizeFilter*>(filter);
@@ -1312,6 +1322,10 @@ void QPixmapDropShadowFilter::draw(QPainter *p,
                                    const QRectF &src) const
 {
     Q_D(const QPixmapDropShadowFilter);
+
+    if (px.isNull())
+        return;
+
     QPixmapFilter *filter = p->paintEngine() && p->paintEngine()->isExtended() ?
         static_cast<QPaintEngineEx *>(p->paintEngine())->pixmapFilter(type(), this) : 0;
     QPixmapDropShadowFilter *dropShadowFilter = static_cast<QPixmapDropShadowFilter*>(filter);