commit 70697ac8327955a488d79aea1bfd6100f400377a
Author: Lamarque V. Souza <lamarque@kde.org>
Date:   Sat May 24 14:21:30 2014 -0300

    Respect external CMAKE_CXX_FLAGS values.

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 5bcf7e2..40ee9c0 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -20,7 +20,7 @@ add_definitions(${QT_DEFINITIONS})
 include(CheckCXXCompilerFlag)
 check_cxx_compiler_flag("-Werror=return-type" HAVE_GCC_ERROR_RETURN_TYPE)
 if (HAVE_GCC_ERROR_RETURN_TYPE)
-    set(CMAKE_CXX_FLAGS "-Werror=return-type")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror=return-type")
 endif()
 
 include_directories(