Subject: [PATCH] build TKIVtkDraw only with Tk, and link Tk into it

Rebased onto OCCT 8.0.1 from ::gentoo opencascade-7.8.1-no-tk.

--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -602,6 +602,14 @@
   OCCT_ADD_VCPKG_FEATURE ("vtk")
   set (OCCT_VTK_USED_TARGETS "" CACHE INTERNAL "" FORCE)
   list (APPEND OCCT_3RDPARTY_CMAKE_LIST "adm/cmake/vtk")
+
+  if (NOT CAN_USE_TK OR NOT USE_TK)
+    list (FIND BUILD_TOOLKITS TKIVtkDraw _HAS_TKIVTKDRAW)
+    if (NOT _HAS_TKIVTKDRAW EQUAL -1)
+      message (STATUS "Info: TKIVtkDraw toolkit excluded due to TK not being available")
+      list (REMOVE_ITEM BUILD_TOOLKITS TKIVtkDraw)
+    endif()
+  endif()
 else()
   OCCT_CHECK_AND_UNSET_GROUP ("3RDPARTY_VTK")
   OCCT_UNSET_VCPKG_FEATURE ("vtk")
--- a/src/Draw/TKIVtkDraw/EXTERNLIB.cmake
+++ b/src/Draw/TKIVtkDraw/EXTERNLIB.cmake
@@ -2,6 +2,7 @@
 set(OCCT_TKIVtkDraw_EXTERNAL_LIBS
   CSF_VTK
   CSF_TclLibs
+  CSF_TclTkLibs
   CSF_XwLibs
   CSF_user32
   TKernel