Because Mercurial's internals are steadily evolving to be simpler and more consistent, we have not yet provided a guaranteed-stable API. This page describes Mercurial internal changes on the development branch to help third-party developers update their code.

Changes from 1.2 to 1.3

    # before
    ui = ui.ui(parentui=parentui, interactive=False)

    # after
    ui = baseui.copy() # there's no longer a parent/child concept
    ui.setconfig('ui', 'interactive', 'off')

Changes from 1.1 to 1.2

Changes from 1.0 to 1.1

    # before
    for src, abs, rel, exact in cmdutil.walk(repo, pats, opts,
                                             node=ctx.node()):

    # after

    m = cmdutil.match(repo, pats, opts)
    for abs in ctx.walk(m):
        rel = m.rel()

    # before
    def status(self, node1=None, node2=None, files=[], match=util.always,
               list_ignored=False, list_clean=False, list_unknown=True):

    # after
    def status(self, node1='.', node2=None, match=None,
               ignored=False, clean=False, unknown=False):

    # before
    a = manifest.linkrev(node)
    b = manifest.linkrev(manifest.node(rev))

    # after
    a = manifest.linkrev(manifest.rev(node))
    b = manifest.linkrev(rev)

    # before
    displayer = cmdutil.show_changeset(ui, repo, opts)
    displayer.show(rev, node)

    # after
    displayer = cmdutil.show_changeset(ui, repo, opts)
    displayer.show(repo[rev]) 

    # before
    keep = { }
    patch.applydiff(..., keep, ...)
    
    print keep
    { 'fname': ( action, other ) }

    # after
    keep = { }
    patch.applydiff(..., keep, ...)
    
    print keep
    { 'fname': action }

as before, action will only be set to anything not-None if the patch is in git-format.

1. Template changes in 1.0

If you use your own template set (particularly for hgweb), here are some relevant changes.