tests: eliminate shutdown race and sleeps in test-serve

tests/test-serve.t

@@ -1,83 +1,82
   $ "$TESTDIR/hghave" serve || exit 80
 
   $ hgserve()
   > {
   >    hg serve -a localhost -d --pid-file=hg.pid -E errors.log -v $@ \
   >        | sed -e "s/:$HGPORT1\\([^0-9]\\)/:HGPORT1\1/g" \
   >              -e "s/:$HGPORT2\\([^0-9]\\)/:HGPORT2\1/g" \
   >              -e 's/http:\/\/[^/]*\//http:\/\/localhost\//'
   >    cat hg.pid >> "$DAEMON_PIDS"
   >    echo % errors
   >    cat errors.log
-  >    sleep 1
   >    if [ "$KILLQUIETLY" = "Y" ]; then
   >        kill `cat hg.pid` 2>/dev/null
   >    else
   >        kill `cat hg.pid`
   >    fi
-  >    sleep 1
+  >    while kill -0 `cat hg.pid` 2>/dev/null; do true; done
   > }
 
   $ hg init test
   $ cd test
   $ echo '[web]' > .hg/hgrc
   $ echo 'accesslog = access.log' >> .hg/hgrc
   $ echo "port = $HGPORT1" >> .hg/hgrc
 
 Without -v
 
   $ hg serve -a localhost -p $HGPORT -d --pid-file=hg.pid -E errors.log
   $ cat hg.pid >> "$DAEMON_PIDS"
   $ if [ -f access.log ]; then
   $     echo 'access log created - .hg/hgrc respected'
   access log created - .hg/hgrc respected
   $ fi
 
 errors
 
   $ cat errors.log
 
 With -v
 
   $ hgserve
   listening at http://localhost/ (bound to 127.0.0.1:HGPORT1)
   % errors
 
 With -v and -p HGPORT2
 
   $ hgserve -p "$HGPORT2"
   listening at http://localhost/ (bound to 127.0.0.1:HGPORT2)
   % errors
 
 With -v and -p daytime (should fail because low port)
 
   $ KILLQUIETLY=Y
   $ hgserve -p daytime
   abort: cannot start server at 'localhost:13': Permission denied
   abort: child process failed to start
   % errors
   $ KILLQUIETLY=N
 
 With --prefix foo
 
   $ hgserve --prefix foo
   listening at http://localhost/foo/ (bound to 127.0.0.1:HGPORT1)
   % errors
 
 With --prefix /foo
 
   $ hgserve --prefix /foo
   listening at http://localhost/foo/ (bound to 127.0.0.1:HGPORT1)
   % errors
 
 With --prefix foo/
 
   $ hgserve --prefix foo/
   listening at http://localhost/foo/ (bound to 127.0.0.1:HGPORT1)
   % errors
 
 With --prefix /foo/
 
   $ hgserve --prefix /foo/
   listening at http://localhost/foo/ (bound to 127.0.0.1:HGPORT1)
   % errors