show cursor on picking and other modes than draw/erase, sanity check on presets file

src/node_panel_brush.cpp

@@ -429,7 +429,17 @@ void NodePanelBrushPreset::init()
         save();
     };
 
-    restore();
+    if (Asset::exist(App::I.data_path + "/settings/presets.bin") && !restore())
+    {
+        auto mb = App::I.message_box("Presets", "Could not read brush presets file, it will be deleted.", true);
+        mb->btn_ok->on_click = [mb](Node*) {
+            Asset::delete_file(App::I.data_path + "/settings/presets.bin");
+            mb->destroy();
+        };
+        mb->btn_cancel->on_click = [mb](Node*) {
+            mb->destroy();
+        };
+    }
 }
 
 kEventResult NodePanelBrushPreset::handle_event(Event* e)
@@ -476,12 +486,14 @@ bool NodePanelBrushPreset::save()
     {
         BinaryStreamWriter sw;
         sw.init();
+        sw.wstring_raw("PPVR");
+        sw.wu16(0);
+        sw.wu16(1);
         sw.wu32(m_container->m_children.size());
         for (int ci = 0; ci < m_container->m_children.size(); ci++)
         {
             auto bpi = static_cast<NodeBrushPresetItem*>(m_container->get_child_at(ci));
             auto& b = bpi->m_brush;
-
             sw << *b;
         }
         fwrite(sw.m_data.data(), sw.m_data.size(), 1, fp);
@@ -501,15 +513,37 @@ bool NodePanelBrushPreset::restore()
         fseek(fp, 0, SEEK_SET);
         std::vector<uint8_t> data(sz);
         fread(data.data(), 1, sz, fp);
+
         BinaryStreamReader sr;
         sr.init(data.data(), sz);
 
+        // sanity checks
+        if (sr.rstring(4) != "PPVR")
+        {
+            LOG("PPVR tag not found")
+            fclose(fp);
+            return false;
+        }
+        auto vmaj = sr.ru16();
+        auto vmin = sr.ru16();
+        if (vmaj != 0 && vmin != 1)
+        {
+            LOG("unrecognised version %d.$d", vmaj, vmin);
+            fclose(fp);
+            return false;
+        }
+
         auto count = sr.ru32();
 
         for (int k = 0; k < count; k++)
         {
             auto b = std::make_shared<Brush>();
-            sr >> *b;
+            if (!b->read(sr))
+            {
+                LOG("error deserializing the brush");
+                fclose(fp);
+                return false;
+            }
 
             if (b->valid())
             {