view tests/test-revlog-packentry.t @ 35746:e5b6ba786d83

branch: allow changing branch name to existing name if possible

With the functionality added in previous patch we can change branches of a
revision but not everytime even if it's possible to do so. For example cosider
the following case:

o 3  added a (foo)
o 2  added b (foo)
o 1  added c (bar)
o 0  added d (bar)

Here if I want to change the branch of rev 2,3 to bar, it was not possible and
it will say, "a branch with same name exists".

This patch allows us to change branch of 2,3 to bar. The underlying logic for
changing branch finds the changesets from the revs passed which have no parents
in revs. We only support revsets which have only one such root, so to support
this we check whether the parent of the root has the same name as that of the
new name and if so, we can use the new name to change branches.

Differential Revision: https://phab.mercurial-scm.org/D1913

  $ hg init repo
  $ cd repo

  $ touch foo
  $ hg ci -Am 'add foo'
  adding foo

  $ hg up -C null
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

this should be stored as a delta against rev 0

  $ echo foo bar baz > foo
  $ hg ci -Am 'add foo again'
  adding foo
  created new head

  $ hg debugindex foo
     rev    offset  length  ..... linkrev nodeid       p1           p2 (re)
       0         0       0  .....       0 b80de5d13875 000000000000 000000000000 (re)
       1         0      13  .....       1 0376abec49b8 000000000000 000000000000 (re)

  $ cd ..