Add a workaround for mixed iconv versions on OS X

cmake/Findiconv.cmake

@@ -30,13 +30,32 @@
 include(UseStaticLibs)
 use_static_libs(iconv)
 
-find_path(iconv_INCLUDE_DIR iconv.h DOC "The directory where iconv.h resides")
+if(APPLE)
+	# Prefer local iconv.h location over the system iconv.h location as /opt/local/include
+	# may be added to the include path by other libraries, resulting in the #include
+	# statements finding the local copy while we will link agains the system lib.
+	# This way we always find both include file and library in /opt/local/ if there is one.
+	find_path(iconv_INCLUDE_DIR iconv.h
+		PATHS /opt/local/include
+		DOC "The directory where iconv.h resides"
+		NO_CMAKE_SYSTEM_PATH
+	)
+endif(APPLE)
+
+find_path(iconv_INCLUDE_DIR iconv.h
+	PATHS /opt/local/include
+	DOC "The directory where iconv.h resides"
+)
 mark_as_advanced(iconv_INCLUDE_DIR)
 
 # Prefer libraries in the same prefix as the include files
 string(REGEX REPLACE "(.*)/include/?" "\\1" iconv_BASE_DIR ${iconv_INCLUDE_DIR})
 
-find_library(iconv_LIBRARY iconv libiconv HINTS "${iconv_BASE_DIR}/lib" DOC "The iconv library")
+find_library(iconv_LIBRARY iconv libiconv
+	HINTS "${iconv_BASE_DIR}/lib"
+	PATHS /opt/local/lib
+	DOC "The iconv library"
+)
 mark_as_advanced(iconv_LIBRARY)
 
 use_static_libs_restore()