PVS-Studio warning V567 for Doom3

int idFileSystemLocal::ListOSFiles(....)
{
  ...
  dir_cache_index = (++dir_cache_index) % MAX_CACHED_DIRS;
  ...
}

This is what should have been written here: dir_cache_index = (dir_cache_index + 1) % MAX_CACHED_DIRS;

This suspicious code was found in Doom3 project by PVS-Studio static code analyzer.
Warning message is:
V567 Undefined behavior. The 'dir_cache_index' variable is modified while being used twice between sequence points. TypeInfo filesystem.cpp 1877

PVS-Studio is a static analyzer for detecting bugs in the source code of applications written in C, C++, C++11, C++/CX. Site: http://www.viva64.com/en/pvs-studio/