manifest: rename 'mf', 'map', and 'mapping' to 'm' We mostly call manifest variables 'm', so let's use that in manifest.py too. This makes it clearer that the variables do, in fact, contain manifestsdict instances and never a plain dict.

manifest: make copy logic local to copy() The optional arguments to the manfifestdict constructor are only used by copy(), so assign the fields from that method instead so it's clear that the arguments are not used for anything else.

extensions: indicate loaded for an immediately called afterload callback Otherwise, there's no way to tell between the immediate callback when it is already loaded, and when the extension is not loaded at all.

tests: add test showing tags cache drops filtered heads (issue4550) The tags cache can lose .hgtags filenode entries for filtered heads. Add a test demonstrating this (bad) behavior.

tags: write tags cache deterministically An upcoming test verifies content of the .hg/cache/tags file. During testing, inconsistent output was observed. This is the result of iterating over a dictionary. Throw a sorted() around tags entries to ensure .hg/cache/tags is written deterministically so test output is stable.

histedit: add --edit-plan option to histedit --edit-plan allows user to edit remaining histedit rules in the middle of histedit process

histedit: generalize makedesc Allow makedesc to generate description for any action - not only pick. (to be used in histedit --edit-plan)

histedit: extract method ruleeditor Extract functionality of editing histedit rules to separate method so we can reuse it in upcoming --edit-plan option.