scmutil.addremove: factor out code to mark added/removed/renames An upcoming patch will reuse this code in another function.

scmutil.addremove: factor out code to find renames This code will be used in a different context in upcoming patches.

scmutil.addremove: rename local 'copies' to 'renames' An upcoming patch will refactor some code out into a method called _findrenames. Having a line saying "copies = _findrenames..." is confusing. Besides, 'renames' is a more precise name for this local anyway.

scmutil.addremove: factor out dirstate walk into another function Upcoming patches will reuse and expand on this function for other purposes.

filecontext: use 'is not None' to check for filelog existence Previously we used 'if filelog:' to check if the filelog existed. If the instance did exist, this pattern then calls len() on the filelog to see if it is empty. I'm developing a filelog replacement that doesn't have len() implemented, so it's better to do an explicit 'is not None' check here instead. Also change _changeid() to return the _changeid attribute if it has it. Previously it would try to obtain it from the _changectx(), and if that did not exist it would construct the _changectx() using the linkrev. In the extension I'm working on, filectx's don't have easy access to linkrevs so avoiding this when possible is better.

filelog: use super() for calling base functions filelog had some hardcoded revlog.revlog.foo() calls. This changes it to use super() instead so that extensions can replace the filelog base class.