4 files changed, 58 insertions, 34 deletions

diff --git a/src/gui/embedded/qscreen_qws.cpp b/src/gui/embedded/qscreen_qws.cpp
index 05771ff..af53cd7 100644
--- a/src/gui/embedded/qscreen_qws.cpp
+++ b/src/gui/embedded/qscreen_qws.cpp
@@ -2420,7 +2420,7 @@ void QScreen::exposeRegion(QRegion r, int windowIndex)
 #endif
     compose(0, r, blendRegion, &blendBuffer, changing);
 
-    if (blendBuffer) {
+    if (blendBuffer && !blendBuffer->isNull()) {
         const QPoint offset = blendRegion.boundingRect().topLeft();
 #ifndef QT_NO_QWS_CURSOR
         if (qt_screencursor && !qt_screencursor->isAccelerated()) {
diff --git a/src/gui/embedded/qsoundqss_qws.cpp b/src/gui/embedded/qsoundqss_qws.cpp
index a45d0fe..e239e14 100644
--- a/src/gui/embedded/qsoundqss_qws.cpp
+++ b/src/gui/embedded/qsoundqss_qws.cpp
@@ -1037,24 +1037,28 @@ void QWSSoundServerPrivate::stopFile(int wid, int sid)
 void QWSSoundServerPrivate::stopAll(int wid)
 {
     QWSSoundServerProvider *bucket;
-    QList<QWSSoundServerProvider*>::Iterator it = active.begin();
-    while (it != active.end()) {
-        bucket = *it;
-        if (bucket->groupId() == wid) {
-            it = active.erase(it);
-            delete bucket;
-        } else {
-            ++it;
+    if (!active.isEmpty()) {
+        QList<QWSSoundServerProvider*>::Iterator it = active.begin();
+        while (it != active.end()) {
+            bucket = *it;
+            if (bucket->groupId() == wid) {
+                it = active.erase(it);
+                delete bucket;
+            } else {
+                ++it;
+            }
         }
     }
-    it = inactive.begin();
-    while (it != inactive.end()) {
-        bucket = *it;
-        if (bucket->groupId() == wid) {
-            it = inactive.erase(it);
-            delete bucket;
-        } else {
-            ++it;
+    if (!inactive.isEmpty()) {
+        QList<QWSSoundServerProvider*>::Iterator it = inactive.begin();
+        while (it != inactive.end()) {
+            bucket = *it;
+            if (bucket->groupId() == wid) {
+                it = inactive.erase(it);
+                delete bucket;
+            } else {
+                ++it;
+            }
         }
     }
 }
diff --git a/src/gui/embedded/qwindowsystem_qws.cpp b/src/gui/embedded/qwindowsystem_qws.cpp
index 624ba84..7384817 100644
--- a/src/gui/embedded/qwindowsystem_qws.cpp
+++ b/src/gui/embedded/qwindowsystem_qws.cpp
@@ -1297,7 +1297,13 @@ QWSServer::QWSServer(int flags, QObject *parent) :
     QObject(*new QWSServerPrivate, parent)
 {
     Q_D(QWSServer);
-    d->initServer(flags);
+    QT_TRY {
+        d->initServer(flags);
+    } QT_CATCH(...) {
+        qwsServer = 0;
+        qwsServerPrivate = 0;
+        QT_RETHROW;
+    }
 }
 
 #ifdef QT3_SUPPORT
@@ -1743,21 +1749,29 @@ void QWSServerPrivate::cleanupFonts(bool force)
 #if defined(QWS_DEBUG_FONTCLEANUP)
     qDebug() << "cleanupFonts()";
 #endif
-    QMap<QByteArray, int>::Iterator it = fontReferenceCount.begin();
-    while (it != fontReferenceCount.end()) {
-        if (it.value() && !force) {
-            ++it;
-            continue;
-        }
+    if (!fontReferenceCount.isEmpty()) {
+        QMap<QByteArray, int>::Iterator it = fontReferenceCount.begin();
+        while (it != fontReferenceCount.end()) {
+            if (it.value() && !force) {
+                ++it;
+                continue;
+            }
 
-        const QByteArray &fontName = it.key();
+            const QByteArray &fontName = it.key();
 #if defined(QWS_DEBUG_FONTCLEANUP)
-        qDebug() << "removing unused font file" << fontName;
+            qDebug() << "removing unused font file" << fontName;
 #endif
-        QFile::remove(QFile::decodeName(fontName));
-        sendFontRemovedEvent(fontName);
-
-        it = fontReferenceCount.erase(it);
+            QT_TRY {
+                QFile::remove(QFile::decodeName(fontName));
+                sendFontRemovedEvent(fontName);
+
+                it = fontReferenceCount.erase(it);
+            } QT_CATCH(...) {
+                // so we were not able to remove the font.
+                // don't be angry and just continue with the next ones.
+                ++it;
+            }
+        }
     }
 
     if (crashedClientIds.isEmpty())
@@ -3959,7 +3973,8 @@ void QWSServerPrivate::openDisplay()
 
 void QWSServerPrivate::closeDisplay()
 {
-    qt_screen->shutdownDevice();
+    if (qt_screen)
+        qt_screen->shutdownDevice();
 }
 
 /*!
@@ -4058,9 +4073,14 @@ void QWSServer::startup(int flags)
 
 void QWSServer::closedown()
 {
-    unlink(qws_qtePipeFilename().toLatin1().constData());
-    delete qwsServer;
+    QScopedPointer<QWSServer> server(qwsServer);
     qwsServer = 0;
+    QT_TRY {
+        unlink(qws_qtePipeFilename().toLatin1().constData());
+    } QT_CATCH(const std::bad_alloc &) {
+        // ### TODO - what to do when we run out of memory
+        // when calling toLatin1?
+    }
 }
 
 void QWSServerPrivate::emergency_cleanup()
diff --git a/src/gui/embedded/qwscursor_qws.cpp b/src/gui/embedded/qwscursor_qws.cpp
index 1930944..e4474ac 100644
--- a/src/gui/embedded/qwscursor_qws.cpp
+++ b/src/gui/embedded/qwscursor_qws.cpp
@@ -531,7 +531,7 @@ void QWSCursor::set(const uchar *data, const uchar *mask,
 
     cursor = QImage(width,height, QImage::Format_Indexed8);
 
-    if (!width || !height || !data || !mask)
+    if (!width || !height || !data || !mask || cursor.isNull())
         return;
 
     cursor.setNumColors(3);