Merge pull request #2801 from RichardTea/fix-2799-2785

MSVC: Disable optimisations in debug build

CMakeLists.txt

@@ -253,7 +253,7 @@ ELSEIF(MSVC)
   IF(MSVC12)
     ADD_COMPILE_OPTIONS(/wd4351)
   ENDIF()
-  SET(CMAKE_CXX_FLAGS_DEBUG "/D_DEBUG /MDd /Ob2 /Zi /O0")
+  SET(CMAKE_CXX_FLAGS_DEBUG "/D_DEBUG /MDd /Zi /Od")
 ELSEIF ( "${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang" )
   IF(NOT HUNTER_ENABLED)
     SET(CMAKE_CXX_FLAGS "-fPIC -std=c++11 ${CMAKE_CXX_FLAGS}")