4 files changed, 6 insertions, 2 deletions
diff --git a/src/gui/kernel/qapplication_win.cpp b/src/gui/kernel/qapplication_win.cpp
index 243e361..ed219cd 100644
--- a/src/gui/kernel/qapplication_win.cpp
+++ b/src/gui/kernel/qapplication_win.cpp
@@ -1009,6 +1009,8 @@ const QString qt_reg_winclass(QWidget *w)        // register window class
 #ifndef QT_NO_DEBUG
     if (!atom)
         qErrnoWarning("QApplication::regClass: Registering window class failed.");
+#else
+    Q_UNUSED(atom);
 #endif
 
     winclassNames()->insert(cname, 1);
diff --git a/src/gui/kernel/qwidget_win.cpp b/src/gui/kernel/qwidget_win.cpp
index dcf541c..46fa3be 100644
--- a/src/gui/kernel/qwidget_win.cpp
+++ b/src/gui/kernel/qwidget_win.cpp
@@ -264,7 +264,7 @@ void QWidgetPrivate::create_sys(WId window, bool initializeWindow, bool destroyO
 
     HINSTANCE appinst  = qWinAppInst();
     HWND parentw, destroyw = 0;
-    WId id;
+    WId id = 0;
 
     QString windowClassName = qt_reg_winclass(q);
 
diff --git a/src/gui/painting/qregion_win.cpp b/src/gui/painting/qregion_win.cpp
index 873439e..249b1a6 100644
--- a/src/gui/painting/qregion_win.cpp
+++ b/src/gui/painting/qregion_win.cpp
@@ -59,7 +59,7 @@ HRGN qt_tryCreateRegion(QRegion::RegionType type, int left, int top, int right,
 {
     const int tries = 10;
     for (int i = 0; i < tries; ++i) {
-        HRGN region;
+        HRGN region = 0;
         switch (type) {
         case QRegion::Rectangle:
             region = CreateRectRgn(left, top, right, bottom);
diff --git a/src/gui/text/qfontdatabase_win.cpp b/src/gui/text/qfontdatabase_win.cpp
index 2e8e5e4..974b955 100644
--- a/src/gui/text/qfontdatabase_win.cpp
+++ b/src/gui/text/qfontdatabase_win.cpp
@@ -1026,6 +1026,8 @@ static void getFamiliesAndSignatures(const QByteArray &fontData, QFontDatabasePr
 
             signature.fsCsb[0] = qFromBigEndian<quint32>(table + 78);
             signature.fsCsb[1] = qFromBigEndian<quint32>(table + 82);
+        } else {
+            memset(&signature, 0, sizeof(signature));
         }
         appFont->signatures << signature;
     }