Errant circuit creation beyond MAPADDRESS validity
I think I found something strange. Consider the following shell script.
for exit in list_of_exits ; do mapaddress example.com=example.com.$exit.exit 
Fire off ten to twenty background processes in parallel that try to connect to example.com. Depending on timing and other issues, some may succeed, some may fail, some may be waiting their timeout retry period due to failure to connect to example.com the first time, etc. Think wget here.
wait - 'wait' them in the shell till they all exit.
mapaddress example.com=example.com  mapaddress example.com.$exit.exit=example.com.$exit.exit  getinfo address-mappings/all done
 Now this map effectively clears the dynamically made map (from ) to the default (no) mapping. And the getinfo confirms it is gone. The shell 'wait' ensures that the spawned processes are all gone and thus do not remain to make further use of the map in .
The bug is... sometimes (while for'ing through the long list of exits), at the end of the next iteration of the loop (and beyond, until the old entry expires), getinfo will show a dynamic entry for the previous exit. Of the form: example.com..exit <it's IP address>..exit "2011-04-xx xx:xx:xx"
My guess is that the processes put in a request for a circuit (by simply trying to connect). But that  doesn't kill that request within Tor, it only removes any dynamic map that currently exists.
I subsequently tested by adding , it had no effect on this issue.
I believe both  and  should kill any pending requests for their respective, formerly mapped, entities.
Also, I see this every once in a while, no real hypothesis other than something similar is going on: example.com <it's IP address> "2011-04-xx xx:xx:xx"