revset: introduce an abstractsmartset class This class documents all methods required by a smartset. This makes it easier for people to respect the API and ensure we fail loudly when something does not. It will later also contain common default implementations for multiple methods, making it easier to have smartset classes with minimal work.

revset: add a `__nonzero__` to baseset We are about to add a base class for `baseset` with an abstract `__nonzero__` method. So we need this method to be explicitly defined to avoid issues. The built-in list object apparently does not have a `__nonzero__` and relies on `__len__` for this purpose?

revset: drop isinstance(baseset) in spanset.__sub__ As baseset now has a fast __contains___ operator, this `baseset.set()` dance is no longer needed. No regressions are visible in the benchmark.

revset: drop isinstance(baseset) in spanset.__and__ As baseset now has a fast __contains___ operator, this `baseset.set()` dance is no longer needed. No regressions are visible in the benchmark.

revset: drop isinstance(baseset) from baseset.__and__ As baseset now has a fast __contains___ operator, this `baseset.set()` dance is no longer needed. No regressions are visible in the benchmark.

revset: use direct access to __contains__ in spanset.__sub__ Using `x.__contains__(r)` instead of `r in x` does not matter for built-in type (set) but have a positive impact for all other classes. This will let us drop some usage of baseset.set() in future patches. This also probably improves some performance.

revset: use a single return statement in matcher function This makes it easy to insert post processing and debug code on the returned value.

obsolete: replace "nb" notation with "num" (for "number") As requested by Matt Mackall.

shelve: remove unused status variables

gpg: use an abort hint and don't mention --force

gpg: move test of force before status call

gpg: drop unnecessary slicing of status array The call to repo.status() does not request status for clean files, so there is no reason to slice it out from the result. Leaving the tuple untouched will simplify a future change.

tag: use an abort hint

tag: only check the status of .hgtags

tag: properly abort if an unknown or ignored .hgtags is present This was a regression introduced by 4faaa0535ea7 in 2008.

summary: remove unused code for listing ignored files The call to repo.status() does not request ignored files to be listed, so remove the code for printing them.

fetch: use cmdutil.bailifchanged() Use the existing method cmdutil.bailifchanged() instead of implementing it again in fetch.py. An effect of this is that the error messages in case of uncommited changes will be different.

ui: fix comment about non-interactive prompts This fixes my earlier in-flight addition to Mads' change.

formatter: convert booleans to json It will be used in branches output.

merge: mute the status message when bid merge kicks in Bid merge is now the default and it is not necessary to tell the user that an experimental feature kicked in. (It could however still be relevant to get a notice that it is one of the rare criss-cross merge situations so the user is warned that the situation is more tricky than usual.)

merge: use bid merge by default (BC) In most cases merges will work exactly as before. The only difference is in criss-cross merge situations where there is multiple ancestors. Instead of picking an more or less arbitrary ancestor, it will consider both ancestors and pick the best bids. Bid merge can be disabled with --config merge.preferancestor='!'.

changectx: skip all invalid merge.preferancestor values A better fix for 17011b36aac7 that will ignore other kinds of "invalid" revisions.

revset: rely on built in iterator when possible in _generatorset.__iter__ Doing manual iteration is expensible. We rely on built in list iteration whenever possible. The other case has to become a closure we cannot have a both yield and return in the same function.

revset: prefetch an attribute in _generatorset.__iter__ Python's attribute lookup are expensible, lets do less of them. This gives us a 7% speedup on this revset iteration (from 0.063403 to 0.059032)