libmng not found on FreeBSD 11

[interkosmos]

Running CMake on FreeBSD 11 leads to:

-- Checking for one of the modules 'libmng'
CMake Error at /usr/local/share/cmake/Modules/FindPkgConfig.cmake:641 (message):
  None of the required 'libmng' found

[interkosmos]

In kdelibs/CMakeLists.txt change line 85 – 87 from:

if(SYSTEM_LIBMNG)
    pkg_search_module(MNG libmng REQUIRED)
endif()

to:

if(SYSTEM_LIBMNG)
pkg_search_module(MNG libmng)
if(NOT MNG_FOUND)
    find_library(MNG_LIBRARIES NAMES mng PATHS /usr/lib /usr/lib64 ${CMAKE_INSTALL_PREFIX} ${LIBMNG_LIBRARY_DIR})
    find_path(MNG_INCLUDEDIR NAMES libmng.h PATHS /usr/include ${CMAKE_INSTALL_FULL_INCLUDEDIR} ${LIBMNG_INCLUDE_DIR})
    add_definitions(-DQT_NO_IMAGEIO_MNG)
    if(NOT MNG_LIBRARIES)
    message(STATUS "Unable to find MNG development files on your system. MNG support will be disabled")
    add_definitions(-DQT_NO_IMAGEIO_MNG)
    set(MNG_LIBRARIES "")
    endif()
endif()
endif()

[heliocastro]

I stated a branch freebsd on qt2 and kdelibs. I think i fixed this one on Qt, but need double check.
I adapted your patch in a different way.