Fix problem with Googletest's LIBRARY_OUTPUT_DIRECTORY (#1135)

The horribly maintained CMake files which are shipped with Googletest
override the library output directory to ${CMAKE_BINARY_DIR}/lib, which
points to the top-level build directory (it should have been
CMAKE_CURRENT_BINARY_DIR).

Unfortunately, that directory is used by setuptools as staging area for
Python modules, and setup.py install will happily install everything it
finds in the lib/ folder, including the libgtest.so binary. Among
others, this has bitten PR2/pr2_mechanism#343 and ros/geometry#223

This PR fixes the output location to something sane(ish).

cmake/test/gtest.cmake

@@ -382,15 +382,23 @@ if(FORCE_GTEST_GMOCK_FROM_SOURCE OR (NOT GMOCK_FOUND AND NOT GTEST_FOUND))
  if(base_dir)
  # overwrite CMake install command to skip install rules for gtest targets
  # which have been added in version 1.8.0
+ # Googletest 1.10 has a INSTALL_GTEST option that we can override,
+ # so we do that, too.
+ option(INSTALL_GTEST "This option must be turned OFF" OFF)
  _use_custom_install()
  set(_CATKIN_SKIP_INSTALL_RULES TRUE)
  add_subdirectory(${base_dir} ${gtest_lib_dir})
  set(_CATKIN_SKIP_INSTALL_RULES FALSE)
+ # Fix output directories, which conflict with Python's setup.py
  set_target_properties(${gtest_libs} ${gtest_main_libs}
- PROPERTIES EXCLUDE_FROM_ALL 1)
+ PROPERTIES EXCLUDE_FROM_ALL 1
+ LIBRARY_OUTPUT_DIRECTORY ${gtest_lib_dir}/lib
+ ARCHIVE_OUTPUT_DIRECTORY ${gtest_lib_dir}/lib)
  if(gmock_found)
  set_target_properties(${gmock_libs} ${gmock_main_libs}
- PROPERTIES EXCLUDE_FROM_ALL 1)
+ PROPERTIES EXCLUDE_FROM_ALL 1
+ LIBRARY_OUTPUT_DIRECTORY ${gtest_lib_dir}/lib
+ ARCHIVE_OUTPUT_DIRECTORY ${gtest_lib_dir}/lib)
  endif()
  endif()