Fixed selection handling bug if zoom level is not 1.0. Zoom factor has to be calculated in Setup() otherwise the selection rectangle uses the wrong zoom level.

Bug was introduced in revision 19253. 
@Ryan: Can you please verify that this fix does not introduce another bug?


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@19648 a95241bf-73f2-0310-859d-f6bbb57e9c96

src/apps/showimage/ShowImageView.cpp

@@ -747,6 +747,7 @@ ShowImageView::Setup(BRect rect)
 {
 	fLeft = floorf(rect.left);
 	fTop = floorf(rect.top);
+	fZoom = (rect.Width()+1.0) / (fBitmap->Bounds().Width()+1.0);
 }