1.39.5 cmake config unconditionally tries to find X11

[anderslanglands]

In one of my builds I'm doing:

-DMATERIALX_BUILD_RENDER=OFF
-DMATERIALX_BUILD_RENDER_PLATFORMS=OFF
-DMATERIALX_BUILD_VIEWER=OFF
-DMATERIALX_BUILD_GRAPH_EDITOR=OFF

in order to get a headless library that will link without x11.

In 1.39.5:

MaterialX/cmake/modules/MaterialXConfig.cmake.in

Line 42 in 257e02f

if(UNIX AND NOT APPLE)

if(UNIX AND NOT APPLE)
    find_dependency(X11 REQUIRED COMPONENTS Xt)
    if("RenderGlsl" IN_LIST MaterialX_FIND_COMPONENTS)
        find_dependency(OpenGL REQUIRED)
        set(MaterialX_RenderGlsl_FOUND TRUE)
    endif()
endif()

Should I think be something like:

if(UNIX AND NOT APPLE AND (TARGET MaterialXRenderHw OR TARGET MaterialXRenderGlsl))
    find_dependency(X11 REQUIRED COMPONENTS Xt)
endif()

if(TARGET MaterialXRenderGlsl)
    find_dependency(OpenGL REQUIRED)
    if("RenderGlsl" IN_LIST MaterialX_FIND_COMPONENTS)
        set(MaterialX_RenderGlsl_FOUND TRUE)
    endif()
endif()