extract: simplify parents assignement We move to the more standard style of: value = default if special: value = other This is more consistent and compact.

patch: move 'extract' return to a dictionnary The final goal here is to be able to parse, return and process arbitrary data from patch. This mirror the recently added ability to add arbitrary data to patch headers. The first step is to return something more flexible, so we return a dict without changing any other logic.

patchbomb: add experimental config of a "pullurl" and export it This config allows to specify a public location where your changeset can be found. It then include a dedicated patch header show a command to be used to retrieve the change. See the test for example. This is flagged as experimental because this feature is not safe until we have more logic to test that: - changeset actually exists on destination - changeset is draft on destination. As all this is experimental, bike shedding can happily happens before we remove the experimental flag.

export: introduce a generic way to add patch header on export Extensions currently have no easy way to add data to exported patch. This is now fixed using a generic mechanism in the same fashion used by bundle2. Tests are coming in the next changeset with its first user.

incoming: request a bundle2 when possible (BC) Incoming was using bundle1 in all cases, as bundle1 is restricted to changegroup1 and does not support general delta, this can lead to significant CPU overhead if the server is using general delta storage. We now properly request and store a bundle2 to disk. If the server include any output or error in the bundle, they will be stored on disk and replayed when the bundle is read. As 'hg incoming' is going to read the bundle right away, we call that 'good' enough and go back to the bigger plan of having general delta on by default. This was tracked as 4864

bundlerepo: indent some code to prepare next patch We are about to add a new condition. Code is indented in a separated patch for readability.