When creating a new page, set the background grid size to the same as

the last active page

src/adaptors/UBSvgSubsetAdaptor.cpp

@@ -466,7 +466,6 @@ UBGraphicsScene* UBSvgSubsetAdaptor::UBSvgSubsetReader::loadScene(UBDocumentProx
                     if (!ubGridSize.isNull()) {
                         int gridSize = ubGridSize.toInt();
 
-                        UBSettings::settings()->crossSize = gridSize;
                         mScene->setBackgroundGridSize(gridSize);
                     }
                 }
@@ -482,7 +481,6 @@ UBGraphicsScene* UBSvgSubsetAdaptor::UBSvgSubsetReader::loadScene(UBDocumentProx
                     if (!ubGridSize.isNull()) {
                         int gridSize = ubGridSize.toInt();
 
-                        UBSettings::settings()->crossSize = gridSize;
                         mScene->setBackgroundGridSize(gridSize);
                     }
                 }

src/core/UBPersistenceManager.cpp

@@ -661,6 +661,7 @@ UBGraphicsScene* UBPersistenceManager::createDocumentSceneAt(UBDocumentProxy* pr
     newScene->setBackground(UBSettings::settings()->isDarkBackground(),
             UBSettings::settings()->UBSettings::pageBackground());
 
+    newScene->setBackgroundGridSize(UBSettings::settings()->crossSize);
     persistDocumentScene(proxy, newScene, index);
 
     proxy->incPageCount();

src/gui/UBBackgroundPalette.cpp

@@ -134,6 +134,7 @@ void UBBackgroundPalette::showEvent(QShowEvent* event)
 void UBBackgroundPalette::sliderValueChanged(int value)
 {
     UBApplication::boardController->activeScene()->setBackgroundGridSize(value);
+    UBSettings::settings()->crossSize = value; // since this function is called (indirectly, by refresh) when we switch scenes, the settings will always have the current scene's cross size.
 }
 
 void UBBackgroundPalette::backgroundChanged()