fileset: use absolute_import

demandimport: support lazy loading for absolute_import Before, we didn't support lazy loading if absolute_import was in effect and a fromlist was used. This meant that "from . import X" wasn't lazy and performance could suffer as a result. With this patch, we now support lazy loading for this scenario. As part of developing this, I discovered issues when module names are defined. Since the enforced import style only allows "from X import Y" or "from .X import Y" in very few scenarios when absolute_import is enabled - scenarios where Y is not a module and thus there is nothing to lazy load - I decided to drop support for this case instead of chasing down the errors. I don't think much harm will come from this. But I'd like to take another look once all modules are using absolute_import and I can see the full extent of what is using names in absolute_import mode.

demandimport: support keyword arguments on _hgextimport __import__ supports keyword arguments since Python 2.5. This proxy should too. An upcoming patch will use this feature.

demandimport: refactor logic and add documentation demandimport doesn't currently support absolute imports (level >= 0). In preparation for this, we add some documentation and a code branch to handle the absolute_import case.

demandimport: add __future__ to ignore list __future__ is special. We should definitely not be trying to lazy load it.

demandimport: remove support for Python < 2.5 The removed code was to support an __import__ function that doesn't support the "level" argument. This argument was added in Python 2.5, which we no longer support.

dispatch: use absolute_import A mixed, ambiguous import has been removed!

commands: break import cycle This was the easiest link in the chain to break as there was only one use of commandserver in commands.py. Other files had multiple users.

cmdutil: break import cycle This was the easiest place to break the chain, as there were only 2 uses of the imported module in the file.

revset: make balanced addsets by orset() without using _combinesets() As scmutil.revrange() was rewritten to not use _combinesets(), we no longer need _combinesets().