[cmake] RP_FindQt4andKDE4.cmake: Preserve the config-specific CFLAGS/…

…CXXFLAGS variables.

KDE4's CMake files overwrite these variables with its own flags, which
breaks the debug build due to the use of GLIBCXX debug iterators:

[ 52%] Linking CXX shared module ../../../lib/rom-properties-kde4.so
CMakeFiles/rom-properties-kde4.dir/__/rp_create_thumbnail.cpp.o: In function `rp_create_thumbnail2':
src/kde/rp_create_thumbnail.cpp:194: undefined reference to `LibRpBase::RpPngWriter::write_tEXt(std::vector<std::pair<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pair<char const*, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > const&)'
CMakeFiles/rom-properties-kde4.dir/__/RomDataView.cpp.o: In function `RomDataViewPrivate::updateMulti(unsigned int)':
src/kde/RomDataView.cpp:793: undefined reference to `LibRpBase::RomFields::getFromStringMulti(std::map<unsigned int, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<unsigned int>, std::allocator<std::pair<unsigned int const, std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > const*, unsigned int, unsigned int)'
CMakeFiles/rom-properties-kde4.dir/__/RomDataView.cpp.o: In function `RomDataViewPrivate::initAgeRatings(QLabel*, LibRpBase::RomFields::Field const&)':
src/kde/RomDataView.cpp:719: undefined reference to `LibRpBase::RomFields::ageRatingsDecode[abi:cxx11](std::array<unsigned short, 16u> const*, bool)'
CMakeFiles/rom-properties-kde4.dir/__/config/CacheCleaner.cpp.o: In function `CacheCleaner::run()':
src/kde/config/CacheCleaner.cpp:98: undefined reference to `LibRpFile::recursiveScan(char const*, std::forward_list<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned char>, std::allocator<std::pair<std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> >, unsigned char> > >&)'
collect2: error: ld returned 1 exit status
src/kde/kde4/CMakeFiles/rom-properties-kde4.dir/build.make:1357: recipe for target 'lib/rom-properties-kde4.so' failed

The debug build now uses std::debug:: variants of the containers, so we
need to preserve the GLIBCXX defines properly.

cmake/libs/RP_FindQt4andKDE4.cmake

@@ -1,5 +1,12 @@
 # Find Qt4 and KDE4.
 MACRO(FIND_QT4_AND_KDE4)
+	# NOTE: KDE4's .cmake files overwrite the per-configuration CFLAGS/CXXFLAGS variables.
+	# We'll need to preserve them here.
+	FOREACH(_config RELWITHDEBINFO RELEASE DEBUG DEBUGFULL PROFILE DEBIAN)
+		SET(OLD_CMAKE_C_FLAGS_${_config}   "${CMAKE_C_FLAGS_${_config}}")
+		SET(OLD_CMAKE_CXX_FLAGS_${_config} "${CMAKE_CXX_FLAGS_${_config}}")
+	ENDFOREACH(_config)
+
 	SET(ENV{QT_SELECT} qt4)
 	SET(QT_DEFAULT_MAJOR_VERSION 4)
 	SET(QT_NO_CREATE_VERSIONLESS_TARGETS TRUE)
@@ -45,4 +52,14 @@ MACRO(FIND_QT4_AND_KDE4)
 		# Qt4 not found.
 		SET(BUILD_KDE4 OFF CACHE INTERNAL "Build the KDE4 plugin." FORCE)
 	ENDIF(QT4_FOUND)
+
+	# NOTE: KDE4's .cmake files overwrite the per-configuration CFLAGS/CXXFLAGS variables.
+	# We'll need to preserve them here.
+	FOREACH(_config RELWITHDEBINFO RELEASE DEBUG DEBUGFULL PROFILE DEBIAN)
+		SET(CMAKE_C_FLAGS_${_config}   "${OLD_CMAKE_C_FLAGS_${_config}}")
+		SET(CMAKE_CXX_FLAGS_${_config} "${OLD_CMAKE_CXX_FLAGS_${_config}}")
+
+		UNSET(OLD_CMAKE_C_FLAGS_${_config})
+		UNSET(OLD_CMAKE_CXX_FLAGS_${_config})
+	ENDFOREACH(_config)
 ENDMACRO(FIND_QT4_AND_KDE4)