pager: skip uisetup if chg is detected chg has its own pager implementation that it wants to skip pager's uisetup. It is currently done by redirecting stdout to /dev/null, which has unintended side effects. This patch makes pager aware of chg and skip uisetup directly from pager. We may want to merge chg and pager's pager implementation to make this unnecessary in the future.

chgserver: add an explicit gc to trigger __del__ SocketServer.ForkingMixIn uses os._exit which will skip all cleanup handlers. We want to run __del__ to make things like transactions, {ssh,http}peer, atomictempfile, dirstateguard, etc. work. This patch adds a "gc.collect()" to trigger __del__. It is helpful for chg to pass some test cases in test-devel-warnings.t.

blackbox: do not assume self._bb{vfs,repo,fp} are set in blackboxui.__init__ It's possible for the blackboxui code to do a "del self._bbvfs", then ui.copy() or similar attempt will fail. It will also fail when constructing a blackboxui from a non-blackbox ui. This patch fixes the issue by not assuming any _bb* attr is set.

chg: downgrade "failed to read channel" from abortmsg to debugmsg If the server has an uncaught exception, it will exit without being able to write the channel information. In this case, the client is likely to complain about "failed to read channel", which looks inconsistent with original hg. This patch silences the error message and makes uncaught exception behavior more like original hg. It will help chg to pass test-fileset.t.