Fixed: #1310 Broken build with VS 2k8 nmake

code/CMakeModules/PCHSupport.cmake

@@ -134,7 +134,9 @@ MACRO(ADD_PRECOMPILED_HEADER_TO_TARGET _targetName _input _pch_output_to_use )
 	ENDIF(CMAKE_COMPILER_IS_GNUCXX)
 
 	SET_TARGET_PROPERTIES(${_targetName} PROPERTIES COMPILE_FLAGS ${_target_cflags})
-	SET_TARGET_PROPERTIES(${_targetName}_pch_dephelp PROPERTIES COMPILE_FLAGS ${oldProps})
+	IF(oldProps)
+		SET_TARGET_PROPERTIES(${_targetName}_pch_dephelp PROPERTIES COMPILE_FLAGS ${oldProps})
+	ENDIF(oldProps)
 	ADD_CUSTOM_TARGET(pch_Generate_${_targetName} DEPENDS ${_pch_output_to_use})
 	ADD_DEPENDENCIES(${_targetName} pch_Generate_${_targetName})
 ENDMACRO(ADD_PRECOMPILED_HEADER_TO_TARGET)