+ fix various warnings

src/Gui/GestureNavigationStyle.cpp

@@ -375,7 +375,7 @@ SbBool GestureNavigationStyle::processSoEvent(const SoEvent * const ev)
                         this->mousedownConsumedEvent[cnt] = *event;//hopefully, a shallow copy is enough. There are no pointers stored in events, apparently. Will loose a subclass, though.
                         cnt++;
                         assert(cnt<=2);
-                        if(cnt>sizeof(mousedownConsumedEvent)){
+                        if(cnt>static_cast<int>(sizeof(mousedownConsumedEvent))){
                             cnt=sizeof(mousedownConsumedEvent);//we are in trouble
                         }
                         processed = true;//just consume this event, and wait for the move threshold to be broken to start dragging/panning

src/Gui/QuantitySpinBox.cpp

@@ -67,6 +67,7 @@ public:
         QString copy = input;
 
         int len = copy.size();
+        pos = len;
         const bool plus = max >= 0;
         const bool minus = min <= 0;
 
@@ -274,7 +275,7 @@ void QuantitySpinBox::userInput(const QString & text)
     Q_D(QuantitySpinBox);
 
     QString tmp = text;
-    int pos;
+    int pos = 0;
     QValidator::State state;
     Base::Quantity res = d->validateAndInterpret(tmp, pos, state);
     if (state == QValidator::Acceptable) {
@@ -446,7 +447,7 @@ void QuantitySpinBox::focusOutEvent(QFocusEvent * event)
 {
     Q_D(QuantitySpinBox);
 
-    int pos;
+    int pos = 0;
     QString text = lineEdit()->text();
     QValidator::State state;
     d->validateAndInterpret(text, pos, state);

src/Gui/Quarter/QtCoinCompatibility.cpp

@@ -60,7 +60,7 @@ QtCoinCompatibility::SbImageToQImage(const SbImage & sbimage, QImage & img)
                         "Implementation not tested for 3 colors or more"
                            );
   }
-  QImage::Format format;
+  QImage::Format format=QImage::Format_Invalid;
   if (nc==3||nc==4) {
     format=QImage::Format_RGB32;
   }