hgweb: make log streams compatible with command server Even though it would be useless to start a web server by a command server, it should be doable in principle. Also, we can't use sys.stdout/err directly on Python 3 because they are unicode streams.

cmdserver: write channel header and payload by a single write() call This makes a channeledoutput thread-safe as long as the underlying fwrite() is thread-safe. Both POSIX and Windows implementations are documented as MT-safe. MT-safety is necessary to use ui.fout and ui.ferr in hgweb.

histedit: use ui.fin to read commands from stdin stdin is wrapped by channeledinput in command-server session.