message: Internals: Splitter Behavior doesn't show a border.
diff: @@ -10345,7 +10345,7 @@ bool ImGui::SplitterBehavior(ImGuiID id, const ImRect& bb, ImGuiAxis axis, float
  // Render
  const ImU32 col = GetColorU32(held ? ImGuiCol_SeparatorActive : hovered ? ImGuiCol_SeparatorHovered : ImGuiCol_Separator);
  - RenderFrame(bb_render.Min, bb_render.Max, col, true, g.Style.FrameRounding);
  + window->DrawList->AddRectFilled(bb_render.Min, bb_render.Max, col, g.Style.FrameRounding);
  return held;
  }
  