COMP: Do not use system Zlib on Windows build

Results in various warnings.

Author: thewtex

Superbuild/External-ITK.cmake

@@ -47,6 +47,14 @@ if(APPLE)
     "-DBUILD_SHARED_LIBS:BOOL=ON"
     )
 endif()
+set(_windows_args)
+set(_zlib_deps zlib)
+if(WIN32)
+  set(_windows_args
+    "-DITK_USE_SYSTEM_ZLIB:BOOL=OFF"
+    )
+  set(_zlib_deps )
+endif()
 
 ExternalProject_Add(ITK
   GIT_REPOSITORY "${git_protocol}://github.com/InsightSoftwareConsortium/ITK.git"
@@ -71,8 +79,9 @@ ExternalProject_Add(ITK
     ${_opencv_args}
     ${_wrap_python_args}
     ${_apple_args}
+    ${_windows_args}
   INSTALL_COMMAND ${CMAKE_COMMAND} -E echo "ITK install skipped"
-  DEPENDS ${ITK_DEPENDENCIES} ${_python_depends} zlib
+  DEPENDS ${ITK_DEPENDENCIES} ${_python_depends} ${_zlib_deps}
   LOG_BUILD 0
 )
 

Superbuild/Superbuild.cmake

@@ -31,8 +31,10 @@ endif()
 set(ITKExamples_DEPENDENCIES )
 set(ITK_DEPENDENCIES )
 
-# Used by ITK, VTK, and Python -- always build it.
-include(${CMAKE_SOURCE_DIR}/External-zlib.cmake)
+# Used by ITK, VTK, -- always build it.
+if(NOT WIN32 OR ITKExamples_USE_VTK AND NOT VTK_DIR)
+  include(${CMAKE_SOURCE_DIR}/External-zlib.cmake)
+endif()
 
 option(ITKExamples_USE_OpenCV "Add OpenCV to the superbuild" OFF)
 if(NOT OpenCV_DIR AND ITKExamples_USE_OpenCV)