Disable texture sharing for now

Under certain circumstances, we could share textures between two
views on the same image. However, someone introduced a bug where
closing a view deletes the shared textures while the other view
is trying to paint using them.

This needs proper fixing, after the alpha.

libs/ui/opengl/kis_opengl_canvas2.cpp

@@ -145,6 +145,7 @@ KisOpenGLCanvas2::KisOpenGLCanvas2(KisCanvas2 *canvas,
                                                  colorConverter->monitorProfile(),
                                                  colorConverter->renderingIntent(),
                                                  colorConverter->conversionFlags());
+
     setAcceptDrops(true);
     setFocusPolicy(Qt::StrongFocus);
     setAttribute(Qt::WA_NoSystemBackground);

libs/ui/opengl/kis_opengl_image_textures.cpp

@@ -142,7 +142,8 @@ KisOpenGLImageTexturesSP KisOpenGLImageTextures::getImageTextures(KisImageWSP im
                                                                   KoColorConversionTransformation::Intent renderingIntent,
                                                                   KoColorConversionTransformation::ConversionFlags conversionFlags)
 {
-    if (imageCanShareTextures()) {
+    // Disabled until we figure out why we're deleting the shared textures on closing the second view on a single image
+    if (false && imageCanShareTextures()) {
         ImageTexturesMap::iterator it = imageTexturesMap.find(image);
 
         if (it != imageTexturesMap.end()) {
@@ -221,7 +222,7 @@ void KisOpenGLImageTextures::createImageTextureTiles()
 
 void KisOpenGLImageTextures::destroyImageTextureTiles()
 {
-    if(m_textureTiles.isEmpty()) return;
+    if (m_textureTiles.isEmpty()) return;
 
     Q_FOREACH (KisTextureTile *tile, m_textureTiles) {
         delete tile;