view tests/test-hooklib-reject_new_heads.t @ 47072:4c041c71ec01

revlog: introduce an explicit tracking of what the revlog is about

Since the dawn of time, people have been forced to rely to lossy introspection
of the index filename to determine what the purpose and role of the revlog they
encounter is. This is hacky, error prone, inflexible, abstraction-leaky,
<insert-your-own-complaints-here>.

In f63299ee7e4d Raphaël introduced a new attribute to track this information:
`revlog_kind`. However it is initialized in an odd place and various instances
end up not having it set. In addition is only tracking some of the information
we end up having to introspect in various pieces of code.

So we add a new attribute that holds more data and is more strictly enforced.
This work is done in collaboration with Raphaël.

The `revlog_kind` one will be removed/adapted in the next changeset. We expect
to be able to clean up various existing piece of code and to simplify coming
work around the newer revlog format.

Differential Revision: https://phab.mercurial-scm.org/D10352

  $ cat <<EOF >> $HGRCPATH
  > [extensions]
  > hooklib =
  > 
  > [phases]
  > publish = False
  > EOF
  $ hg init a
  $ hg --cwd a debugbuilddag '.:parent.*parent'
  $ hg --cwd a log -G
  o  changeset:   2:fa942426a6fd
  |  tag:         tip
  |  parent:      0:1ea73414a91b
  |  user:        debugbuilddag
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     r2
  |
  | o  changeset:   1:66f7d451a68b
  |/   user:        debugbuilddag
  |    date:        Thu Jan 01 00:00:01 1970 +0000
  |    summary:     r1
  |
  o  changeset:   0:1ea73414a91b
     tag:         parent
     user:        debugbuilddag
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     r0
  
  $ hg init b
  $ cat <<EOF >> b/.hg/hgrc
  > [hooks]
  > pretxnclose.reject_new_heads = \
  >   python:hgext.hooklib.reject_new_heads.hook
  > EOF
  $ hg --cwd b pull ../a
  pulling from ../a
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  error: pretxnclose.reject_new_heads hook failed: Changes on branch 'default' resulted in multiple heads
  transaction abort!
  rollback completed
  abort: Changes on branch 'default' resulted in multiple heads
  [255]
  $ hg --cwd b pull ../a -r 1ea73414a91b
  pulling from ../a
  adding changesets
  adding manifests
  adding file changes
  added 1 changesets with 0 changes to 0 files
  new changesets 1ea73414a91b (1 drafts)
  (run 'hg update' to get a working copy)