zeroconf: suppress traceback during shutdown
If the read thred is in select when the main thread is in close, the main
thread may close the socket between select and read, generating a noisy
traceback. This can be ignored if the shutdown flag is set.
#!/bin/sh
hg init a
cd a
hg log
hg grep wah
hg manifest
hg verify
ls .hg
ls .hg/store
cd ..
hg clone a b
cd b
hg verify
ls .hg
ls .hg/store