[PATCH v4 0/9] MR5665: For a CS_PARENTDC child use parent for visible region calculations.

[Dmitry Timoshkov (＠dmitry)]

These patches fix painting in an application that draws outside of a CS_PARENTDC child
client area in its WM_PAINT handler.

Comments and suggestions are welcome.

--
  v4: win32u: Use parent rectangle for visible region calculations of a CS_PARENTDC child.
      win32u: Don't clip update region to the window client rectangle.
      win32u: GetUpdateRect() should clip update rectangle to the window client area.
      win32u: GetUpdateRgn() should clip update region to the window client area.
      win32u: Clip PAINTSTRUCT.rcPaint to the window client area.
      server: For a CS_PARENTDC child use parent for visible region calculations.
      server: If the being validated region covers whole window then validate everything.
      user32/tests: Add a message test for listbox redrawing after LB_SETCOUNT.
      user32/tests: Test BeginPaint() clipbox of cropped window with CS_PARENTDC.

https://gitlab.winehq.org/wine/wine/-/merge_requests/5665