repoview: protect `base` computation from weird phase root
If for some reason the phase roots contains nullid, the set of filtered revs
will contains -1. That confuse Mercurial a lot. In particular this corrupt the
branchcache.
Standard code path does not result in nullid phase root. It can only result from
altered `.hg/store/phaseroots` or buggy extension. However better safe than
sorry.
$ "$TESTDIR/hghave" serve || exit 80
#if windows
$ hg clone http://localhost:$HGPORT/ copy
abort: * (glob)
[255]
#else
$ hg clone http://localhost:$HGPORT/ copy
abort: error: Connection refused
[255]
#endif
$ test -d copy
[1]
$ cat > dumb.py <<EOF
> import BaseHTTPServer, SimpleHTTPServer, os, signal
> def run(server_class=BaseHTTPServer.HTTPServer,
> handler_class=SimpleHTTPServer.SimpleHTTPRequestHandler):
> server_address = ('localhost', int(os.environ['HGPORT']))
> httpd = server_class(server_address, handler_class)
> open("listening", "w")
> httpd.handle_request()
> run()
> EOF
$ python dumb.py 2> log &
$ P=$!
$ while [ ! -f listening ]; do sleep 0; done
$ hg clone http://localhost:$HGPORT/foo copy2
abort: HTTP Error 404: * (glob)
[255]
$ wait $P