branchmap: add a copy method If we want branchcache of different filter to collaborate, they need a simple way to copy each other. This will ensure that each filtered have no side effect on other filter level cache.

clfilter: use empty frozenset intead of empty tuple This will allows set operation needed for cache collaboration.

run-tests.py: don't use console for stdin when running in debug mode Tests would wait for input instead of using non-interactive mode.

tests: make hghave and run-tests exit on unknown feature requirements

test-largefiles.t: fix wrong '#if hgweb' - it should be '#if serve' A bug introduced in 0c1d10351869 did that a part of the test never was run.

dispatch: show empty filename in OSError aborts Mercurial would sometimes exit with: abort: No such file or directory where str of the actual OSError exception was the more helpful: [Errno 2] No such file or directory: '' The exception will now always show the filename and quote it: abort: No such file or directory: ''

test-dispatch.t: remove incorrect "cd $dir" A line that should have been removed in 50fbe9063ff2.