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
mkdir t
cd t
hg init
echo a > a
hg ci -Ama -d '1000000000 0'
echo b > b
hg branch b
hg ci -Amb -d '1000000000 0'
hg co -C 0
echo fast-forward
hg merge b
hg ci -Ammerge -d '1000000000 0'
echo bogus fast-forward should fail
hg merge b
echo done