demandimport: insert empty line per method _demandmod class is getting bigger, and I don't want to put more things in a dense form.

demandimport: strictly compare identity of proxy object This looks better, and __eq__() may be overridden in an undesired way.

match: use ProgrammingError where appropriate

revlog: raise error.WdirUnsupported from revlog.node() if wdirrev is passed When we try to run, 'hg debugrevspec 'branch(wdir())'', it throws an index error and blows up. Lets raise the WdirUnsupported if wdir() is passed so that we can catch that later.

revset: add support for ancestors(wdir()) This is a part of extending support for wdir() predicate.

revset: add support for using ~ operator on wdir() predicate We catch the WdirUnsupported exception and handles the wdir() case here.

revset: add support for p2(wdir()) to get second parent of working directory This adds support for finding the second parent of working directory using the p2 predicate.

revset: use try-except instead of if-else because of perf For wdir(), we now raises an exception which will be raised when wdir() will be passed, so catching that exception is better checking for wdir() using if-else.

revset: remove redundant condition and change to else from elif Before going to this piece of code, we already check whether n is in [0, 1, 2], so dropping the redundant condition.

tests: add tests for predicates and operators which works with wdir() This one is cluttering up the test file though.