3 files changed, 15 insertions, 4 deletions
diff --git a/src/printsupport/dialogs/qprintdialog_unix.cpp b/src/printsupport/dialogs/qprintdialog_unix.cpp
index f3be45262b..a15fd51c98 100644
--- a/src/printsupport/dialogs/qprintdialog_unix.cpp
+++ b/src/printsupport/dialogs/qprintdialog_unix.cpp
@@ -231,6 +231,7 @@ public:
 QPrintPropertiesDialog::QPrintPropertiesDialog(QAbstractPrintDialog *parent)
     : QDialog(parent)
 {
+    setWindowTitle(tr("Printer Properties"));
     QVBoxLayout *lay = new QVBoxLayout(this);
     this->setLayout(lay);
     QWidget *content = new QWidget(this);
@@ -803,7 +804,7 @@ void QUnixPrintWidgetPrivate::applyPrinterProperties()
         QString cur = QDir::currentPath();
         if (home.at(home.length()-1) != QLatin1Char('/'))
             home += QLatin1Char('/');
-        if (cur.at(cur.length()-1) != QLatin1Char('/'))
+        if (!cur.isEmpty() && cur.at(cur.length()-1) != QLatin1Char('/'))
             cur += QLatin1Char('/');
         if (cur.left(home.length()) != home)
             cur = home;
diff --git a/src/printsupport/kernel/qpaintengine_alpha.cpp b/src/printsupport/kernel/qpaintengine_alpha.cpp
index 710691453a..0ae9464b69 100644
--- a/src/printsupport/kernel/qpaintengine_alpha.cpp
+++ b/src/printsupport/kernel/qpaintengine_alpha.cpp
@@ -376,6 +376,7 @@ QAlphaPaintEnginePrivate::QAlphaPaintEnginePrivate()
         m_pic(0),
         m_picengine(0),
         m_picpainter(0),
+        m_numberOfCachedRects(0),
         m_hasalpha(false),
         m_alphaPen(false),
         m_alphaBrush(false),
@@ -426,7 +427,14 @@ void QAlphaPaintEnginePrivate::addAlphaRect(const QRectF &rect)
 
 bool QAlphaPaintEnginePrivate::canSeeTroughBackground(bool somethingInRectHasAlpha, const QRectF &rect) const
 {
-    return somethingInRectHasAlpha && m_dirtyrgn.intersects(rect.toAlignedRect());
+    if (somethingInRectHasAlpha) {
+        if (m_dirtyRects.count() != m_numberOfCachedRects) {
+            m_cachedDirtyRgn.setRects(m_dirtyRects.constData(), m_dirtyRects.count());
+            m_numberOfCachedRects = m_dirtyRects.count();
+        }
+        return m_cachedDirtyRgn.intersects(rect.toAlignedRect());
+    }
+    return false;
 }
 
 void QAlphaPaintEnginePrivate::drawAlphaImage(const QRectF &rect)
diff --git a/src/printsupport/kernel/qpaintengine_alpha_p.h b/src/printsupport/kernel/qpaintengine_alpha_p.h
index 2becad7379..49a9938e56 100644
--- a/src/printsupport/kernel/qpaintengine_alpha_p.h
+++ b/src/printsupport/kernel/qpaintengine_alpha_p.h
@@ -99,7 +99,9 @@ public:
 
     QRegion m_alphargn;
     QRegion m_cliprgn;
-    QRegion m_dirtyrgn;
+    mutable QRegion m_cachedDirtyRgn;
+    mutable int m_numberOfCachedRects;
+    QVector<QRect> m_dirtyRects;
 
     bool m_hasalpha;
     bool m_alphaPen;
@@ -115,7 +117,7 @@ public:
     QPen m_pen;
 
     void addAlphaRect(const QRectF &rect);
-    void addDirtyRect(const QRectF &rect) { m_dirtyrgn |= rect.toAlignedRect(); }
+    void addDirtyRect(const QRectF &rect) { m_dirtyRects.append(rect.toAlignedRect()); }
     bool canSeeTroughBackground(bool somethingInRectHasAlpha, const QRectF &rect) const;
 
     QRectF addPenWidth(const QPainterPath &path);