revert: add a message to noop action This prepares for the arrival of a second "not touching file" action: revert of an untracked file.

revert: simplify loop conditional The two breaks can be joined into one. The code gains one level of indent.

revert: explode the action tuple in the for loop noop is about to gain a message.

revert: use actions[...] in all disptable cases 1. Special cases are not special enough 2. There are two cases where nothing is done and a message is displayed. This prepares it.

revset: factorize backup decision The conditional controlling the creation of backup is fairly big. We move config related decisions outside of the loop.

revert: use a flat dispatch table Now that the table is simpler, remove one level of depth from it. This simplifies its usage in the for loop.

pushbookmark: do not attempt to update bookmarks if the push failed (BC) Before this patch, there was always an attempt to update bookmark even if prior steps of the push failed. I cannot see a good semantic reason to do so. We disable this possibility to simplify the push flow with bundle2. Bookmarks will be included in the bundle and fail with other steps.

pushbookmark: remove a <cond> and <val> or <other> construct We make the conditional explicit for the sake of readability.

pushbookmark: stop unrolling ancestors Now that ancestors has the same boolean property as a list, we can stop unrolling the set of ancestors. This should provide a significant speedup to this step as ancestor objects are smart and lazy.

ancestors: add a __nonzero__ method This allows using the object in a conditional the same way we can use list.