tests/printrevset.py

abort: added logic for of hg abort

This is part of `GSoC19` project `Implement abort and
continue commands`. This patch is part of the `abort plan`.

This adds the basic logic for `hg abort`. This command
aborts an multistep operation like graft, histedit, rebase,
merge and unshelve if they are in an unfinished state.

The first part of the logic is determining the unfinished
operation from the state detection API under `statemod`.
This API is extended to support `hg abort` by adding a method
to register the abort logic as a function (here `abortfunc`).

Once the unfinished operation is determined the registered
logic is used to abort the command. The benefit of this kind
of framework is that any new extension developed can support
`hg abort` by registering the command and logic under
statedetection API.

`hg abort` currently supports `--dry-run/-n` flag only.
It is used to dry run `hg abort`

Further patches sequentially add support for `graft`, `rebase`,
`unshelve`, `histedit` and `merge`.

Differential Revision: https://phab.mercurial-scm.org/D6566

from __future__ import absolute_import
from mercurial import (
  cmdutil,
  commands,
  extensions,
  logcmdutil,
  revsetlang,
  smartset,
)

from mercurial.utils import (
  stringutil,
)

def logrevset(repo, pats, opts):
    revs = logcmdutil._initialrevs(repo, opts)
    if not revs:
        return None
    match, pats, slowpath = logcmdutil._makematcher(repo, revs, pats, opts)
    return logcmdutil._makerevset(repo, match, pats, slowpath, opts)

def uisetup(ui):
    def printrevset(orig, repo, pats, opts):
        revs, filematcher = orig(repo, pats, opts)
        if opts.get(b'print_revset'):
            expr = logrevset(repo, pats, opts)
            if expr:
                tree = revsetlang.parse(expr)
                tree = revsetlang.analyze(tree)
            else:
                tree = []
            ui = repo.ui
            ui.write(b'%s\n' % stringutil.pprint(opts.get(b'rev', [])))
            ui.write(revsetlang.prettyformat(tree) + b'\n')
            ui.write(stringutil.prettyrepr(revs) + b'\n')
            revs = smartset.baseset()  # display no revisions
        return revs, filematcher
    extensions.wrapfunction(logcmdutil, 'getrevs', printrevset)
    aliases, entry = cmdutil.findcmd(b'log', commands.table)
    entry[1].append((b'', b'print-revset', False,
                     b'print generated revset and exit (DEPRECATED)'))