Generally speaking we don't bother freeing storage just before program exit 
merely to pacify AddressSanitizer, as that makes the program less efficient and 
is contrary to the goal of leak checking which is to increase efficiency. Here, 
though, we can free storage earlier, and this might have a point since the 
storage can get reused. So I installed the attached further patch.

> I'm aware that I can set ASAN_OPTIONS=detect_leaks=0 in the environment

It might not hurt to do that, if only to prevent our hassling with false alarms.