topics: add t0 and b0 to the stack t0 or b0 will be the base of the stack and it's the parent of t1 or b1. The cool thing about this is that if you update to t0 using `hg up t0` or do `hg prev` on t1, you will be updated to t0 with the current topic preserved. This patch adds t0 to stack and implement the preserving topic case for t0 while using `hg update`.

topics: wrap the update function to check if either t0 or b0 is passed as rev t0 or b0, seriously, what's that. Do they even exist? Hold on and look for the next commits what we are trying to do.

compat: adapt to change in 53b3a1968aa6-core

merge back with stable (version updated in the process)

packaging: update versions to '.dev' one This help to spot install from unreleased source.

Added tag 6.5.0 for changeset 734c0bc066cd

packaging: prepare version 6.5.0

topic: update extensions metadata Let us assign a version number to this release and add some more data about the extensions.

readme: prepare version 6.5.0

compat: merge with mercurial-3.9

compat: merge with mercurial-4.0

compat: merge with mercurial-4.1

compat: merge with stable Nothing to report beside the drop of the obsfate related tests.

evolve: preserve the branch of the original changeset when evolving merge

merge: default into stable to prepare next version Let us prepare ourself for 6.5.0

obslog: handle patch generation for mercurial 4.1- The unidiff API changed, we detect and work around that.

topic: also have the revbranchcache during the discovery

topic: cleanup the repository wrapping logic in topic discovery We are know overriding the class so we do not need to update and restore the pushop itself.

topic: adapt to function migrate to obsutil Mercurial 4.3 has a new module "obsutil" and multiple functions moved there. We handle the move for the one we care about.

evolve: adapt to function migrate to obsutil Mercurial 4.3 has a new module "obsutil" and multiple functions moved there. We handle the move for the one we care about.

topic: directly use the '_notpublic' revset This is just more robust to achieve the same goal.

topic: drop the message about running evolve after topic change Topic change is no longer creating a mess that needs cleaning.

template: handle lack of "users" in the obsfate data This can happens when their are no markers (or the markers has no user data?)

doc: update effect flag documentation

obsfate: override the default log output Override the default log output by showing obsfate if not empty.

evolve: fix documentation formatting The config example were formatted as standard paragraph.

compat: fix topicset for mercurial 4.1 The 'getrevset' method is not available there.

obsfate: refactor obsfate data computing Refactor how obsfate data are computed in order to reuse this logic later when hooking on default log output.

topic: exclude public and topic changeset from branch stack Stack use-case is to show the current work in progress, which are symbolized by the phase draft and secret phase. Moreover showing public changesets in stack output when displaying current branch would display a lot of changesets for long-lived branches and would be quite useless. We also exclude topic changeset form the stack since they already exist on their own stack. getstack revsets didn't needed update when displaying a topic as when a changeset become public, its topic is no longer relevant.

tests: use a more portable form for new lines