fixed: errors in templates could cause program to hang/crash

src/gui/set/style_panel.cpp

@@ -108,6 +108,9 @@ void StylePanel::selectCard(const CardP& card) {
 void StylePanel::onStyleSelect(wxCommandEvent&) {
 	if (list->hasSelection() && card) {
 		StyleSheetP stylesheet = list->getSelection<StyleSheet>();
+		if (stylesheet->game != set->game) {
+			throw PackageError(_("Stylesheet made for the wrong game"));
+		}
 		if (stylesheet == set->stylesheet) {
 			// select no special style when selecting the same style as the set default
 			stylesheet = StyleSheetP();

src/render/value/image.cpp

@@ -21,7 +21,7 @@ IMPLEMENT_VALUE_VIEWER(Image);
 
 void ImageValueViewer::draw(RotatedDC& dc) {
 	// reset?
-	int w = (int)dc.trX(style().width), h = (int)dc.trY(style().height);
+	int w = max(0,(int)dc.trX(style().width)), h = max(0,(int)dc.trY(style().height));
 	int a = dc.trAngle(0); //% TODO : Add getAngle()?
 	if (bitmap.Ok() && (a != angle || size.width != w || size.height != h)) {
 		bitmap = Bitmap();