Fixed casual crash in initializeDb (Symbian)

dynamic_cast should be used carefully with rvct before version 4.

We found that out after the a dynamic (down)-cast from CFont* to
CFbsFont* in QtGui suddenly failed.

We test for (TypeUid() == KCFbsFontUid), before doing the
cast. So, a static_cast is safe in this case. Also the other
two dynamic_casts in qfontdatabase_s60.cpp were changed to
static_cast.

http://bugreports.qt.nokia.com/browse/QTBUG-7963

Task-number: QTBUG-7963
Reviewed-by: lars

	modified:   src/gui/text/qfontdatabase_s60.cpp
(cherry picked from commit 3b7164b3188e9382510bef2211e82ef777faa75c)

1 files changed, 5 insertions, 6 deletions

diff --git a/src/gui/text/qfontdatabase_s60.cpp b/src/gui/text/qfontdatabase_s60.cpp
index e36940f..b6a187a 100644
--- a/src/gui/text/qfontdatabase_s60.cpp
+++ b/src/gui/text/qfontdatabase_s60.cpp
@@ -246,8 +246,8 @@ static void initializeDb()
     QSymbianFbsHeapLock lock(QSymbianFbsHeapLock::Unlock);
     
     const int numTypeFaces = QS60Data::screenDevice()->NumTypefaces();
-    const QFontDatabaseS60StoreImplementation *store = dynamic_cast<const QFontDatabaseS60StoreImplementation*>(db->s60Store);
-    Q_ASSERT(store);
+    const QFontDatabaseS60StoreImplementation *store =
+            static_cast<const QFontDatabaseS60StoreImplementation*>(db->s60Store);
     bool fontAdded = false;
     for (int i = 0; i < numTypeFaces; i++) {
         TTypefaceSupport typefaceSupport;
@@ -258,8 +258,7 @@ static void initializeDb()
             continue;
         if (font->TypeUid() == KCFbsFontUid) {
             TOpenFontFaceAttrib faceAttrib;
-            const CFbsFont *cfbsFont = dynamic_cast<const CFbsFont *>(font);
-            Q_ASSERT(cfbsFont);
+            const CFbsFont *cfbsFont = static_cast<const CFbsFont *>(font);
             cfbsFont->GetFaceAttrib(faceAttrib);
 
             QtFontStyle::Key styleKey;
@@ -390,8 +389,8 @@ QFontEngine *QFontDatabase::findFont(int script, const QFontPrivate *, const QFo
         QFontDef request = req;
         request.family = fontFamily;
 #if defined(QT_NO_FREETYPE)
-        const QFontDatabaseS60StoreImplementation *store = dynamic_cast<const QFontDatabaseS60StoreImplementation*>(db->s60Store);
-        Q_ASSERT(store);
+        const QFontDatabaseS60StoreImplementation *store =
+                static_cast<const QFontDatabaseS60StoreImplementation*>(db->s60Store);
         const QFontEngineS60Extensions *extension = store->extension(fontFamily);
         fe = new QFontEngineS60(request, extension);
 #else