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
echo "nothing" > a
hg add a
hg commit -m ancestor -d "1000000 0"
echo "something" > a
hg commit -m branch1 -d "1000000 0"
hg co 0
echo "something else" > a
hg commit -m branch2 -d "1000000 0"
hg merge 1
hg id
cat a
hg status