uncommit: convert _fixdirstate() into _movedirstate()

_fixdirstate() already also updates to the given commit, so let's
rename it to _movedirstate(). Also update the documentation and drop
the unnecessary "curctx" argument, since that should always be
repo['.'].

Differential Revision: https://phab.mercurial-scm.org/D6117

hgext/uncommit.py

@@ -1,262 +1,261 b''
 # uncommit - undo the actions of a commit
 #
 # Copyright 2011 Peter Arrenbrecht <[e-mail]>
 #                Logilab SA        <[e-mail]>
 #                Pierre-Yves David <[e-mail]>
 #                Patrick Mezard <[e-mail]>
 # Copyright 2016 Facebook, Inc.
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 """uncommit part or all of a local changeset (EXPERIMENTAL)
 
 This command undoes the effect of a local commit, returning the affected
 files to their uncommitted state. This means that files modified, added or
 removed in the changeset will be left unchanged, and so will remain modified,
 added and removed in the working directory.
 """
 
 from __future__ import absolute_import
 
 from mercurial.i18n import _
 
 from mercurial import (
     cmdutil,
     commands,
     context,
     copies as copiesmod,
     error,
     node,
     obsutil,
     pycompat,
     registrar,
     rewriteutil,
     scmutil,
 )
 
 cmdtable = {}
 command = registrar.command(cmdtable)
 
 configtable = {}
 configitem = registrar.configitem(configtable)
 
 configitem('experimental', 'uncommitondirtywdir',
     default=False,
 )
 configitem('experimental', 'uncommit.keep',
     default=False,
 )
 
 # Note for extension authors: ONLY specify testedwith = 'ships-with-hg-core' for
 # extensions which SHIP WITH MERCURIAL. Non-mainline extensions should
 # be specifying the version(s) of Mercurial they are tested with, or
 # leave the attribute unspecified.
 testedwith = 'ships-with-hg-core'
 
 def _commitfiltered(repo, ctx, match, keepcommit):
     """Recommit ctx with changed files not in match. Return the new
     node identifier, or None if nothing changed.
     """
     base = ctx.p1()
     # ctx
     initialfiles = set(ctx.files())
     exclude = set(f for f in initialfiles if match(f))
 
     # No files matched commit, so nothing excluded
     if not exclude:
         return None
 
     # return the p1 so that we don't create an obsmarker later
     if not keepcommit:
         return ctx.p1().node()
 
     files = (initialfiles - exclude)
     # Filter copies
     copied = copiesmod.pathcopies(base, ctx)
     copied = dict((dst, src) for dst, src in copied.iteritems()
                   if dst in files)
     def filectxfn(repo, memctx, path, contentctx=ctx, redirect=()):
         if path not in contentctx:
             return None
         fctx = contentctx[path]
         mctx = context.memfilectx(repo, memctx, fctx.path(), fctx.data(),
                                   fctx.islink(),
                                   fctx.isexec(),
                                   copied=copied.get(path))
         return mctx
 
     if not files:
         repo.ui.status(_("note: keeping empty commit\n"))
 
     new = context.memctx(repo,
                          parents=[base.node(), node.nullid],
                          text=ctx.description(),
                          files=files,
                          filectxfn=filectxfn,
                          user=ctx.user(),
                          date=ctx.date(),
                          extra=ctx.extra())
     return repo.commitctx(new)
 
-def _fixdirstate(repo, oldctx, newctx, match=None):
-    """ fix the dirstate after switching the working directory from oldctx to
-    newctx which can be result of either unamend or uncommit.
-    """
+def _movedirstate(repo, newctx, match=None):
+    """Move the dirstate to newctx and adjust it as necessary."""
+    oldctx = repo['.']
     ds = repo.dirstate
     ds.setparents(newctx.node(), node.nullid)
     copies = dict(ds.copies())
     s = newctx.status(oldctx, match=match)
     for f in s.modified:
         if ds[f] == 'r':
             # modified + removed -> removed
             continue
         ds.normallookup(f)
 
     for f in s.added:
         if ds[f] == 'r':
             # added + removed -> unknown
             ds.drop(f)
         elif ds[f] != 'a':
             ds.add(f)
 
     for f in s.removed:
         if ds[f] == 'a':
             # removed + added -> normal
             ds.normallookup(f)
         elif ds[f] != 'r':
             ds.remove(f)
 
     # Merge old parent and old working dir copies
     oldcopies = copiesmod.pathcopies(newctx, oldctx, match)
     oldcopies.update(copies)
     copies = dict((dst, oldcopies.get(src, src))
                   for dst, src in oldcopies.iteritems())
     # Adjust the dirstate copies
     for dst, src in copies.iteritems():
         if (src not in newctx or dst in newctx or ds[dst] != 'a'):
             src = None
         ds.copy(src, dst)
 
 @command('uncommit',
     [('', 'keep', None, _('allow an empty commit after uncommiting')),
      ('', 'allow-dirty-working-copy', False,
     _('allow uncommit with outstanding changes'))
     ] + commands.walkopts,
     _('[OPTION]... [FILE]...'),
     helpcategory=command.CATEGORY_CHANGE_MANAGEMENT)
 def uncommit(ui, repo, *pats, **opts):
     """uncommit part or all of a local changeset
 
     This command undoes the effect of a local commit, returning the affected
     files to their uncommitted state. This means that files modified or
     deleted in the changeset will be left unchanged, and so will remain
     modified in the working directory.
 
     If no files are specified, the commit will be pruned, unless --keep is
     given.
     """
     opts = pycompat.byteskwargs(opts)
 
     with repo.wlock(), repo.lock():
 
         m, a, r, d = repo.status()[:4]
         isdirtypath = any(set(m + a + r + d) & set(pats))
         allowdirtywcopy = (opts['allow_dirty_working_copy'] or
                     repo.ui.configbool('experimental', 'uncommitondirtywdir'))
         if not allowdirtywcopy and (not pats or isdirtypath):
             cmdutil.bailifchanged(repo, hint=_('requires '
                                 '--allow-dirty-working-copy to uncommit'))
         old = repo['.']
         rewriteutil.precheck(repo, [old.rev()], 'uncommit')
         if len(old.parents()) > 1:
             raise error.Abort(_("cannot uncommit merge changeset"))
 
         with repo.transaction('uncommit'):
             match = scmutil.match(old, pats, opts)
             keepcommit = pats
             if not keepcommit:
                 if opts.get('keep') is not None:
                     keepcommit = opts.get('keep')
                 else:
                     keepcommit = ui.configbool('experimental', 'uncommit.keep')
             newid = _commitfiltered(repo, old, match, keepcommit)
             if newid is None:
                 ui.status(_("nothing to uncommit\n"))
                 return 1
 
             mapping = {}
             if newid != old.p1().node():
                 # Move local changes on filtered changeset
                 mapping[old.node()] = (newid,)
             else:
                 # Fully removed the old commit
                 mapping[old.node()] = ()
 
             with repo.dirstate.parentchange():
-                _fixdirstate(repo, old, repo[newid], match)
+                _movedirstate(repo, repo[newid], match)
 
             scmutil.cleanupnodes(repo, mapping, 'uncommit', fixphase=True)
 
 def predecessormarkers(ctx):
     """yields the obsolete markers marking the given changeset as a successor"""
     for data in ctx.repo().obsstore.predecessors.get(ctx.node(), ()):
         yield obsutil.marker(ctx.repo(), data)
 
 @command('unamend', [], helpcategory=command.CATEGORY_CHANGE_MANAGEMENT,
          helpbasic=True)
 def unamend(ui, repo, **opts):
     """undo the most recent amend operation on a current changeset
 
     This command will roll back to the previous version of a changeset,
     leaving working directory in state in which it was before running
     `hg amend` (e.g. files modified as part of an amend will be
     marked as modified `hg status`)
     """
 
     unfi = repo.unfiltered()
     with repo.wlock(), repo.lock(), repo.transaction('unamend'):
 
         # identify the commit from which to unamend
         curctx = repo['.']
 
         rewriteutil.precheck(repo, [curctx.rev()], 'unamend')
 
         # identify the commit to which to unamend
         markers = list(predecessormarkers(curctx))
         if len(markers) != 1:
             e = _("changeset must have one predecessor, found %i predecessors")
             raise error.Abort(e % len(markers))
 
         prednode = markers[0].prednode()
         predctx = unfi[prednode]
 
         # add an extra so that we get a new hash
         # note: allowing unamend to undo an unamend is an intentional feature
         extras = predctx.extra()
         extras['unamend_source'] = curctx.hex()
 
         def filectxfn(repo, ctx_, path):
             try:
                 return predctx.filectx(path)
             except KeyError:
                 return None
 
         # Make a new commit same as predctx
         newctx = context.memctx(repo,
                                 parents=(predctx.p1(), predctx.p2()),
                                 text=predctx.description(),
                                 files=predctx.files(),
                                 filectxfn=filectxfn,
                                 user=predctx.user(),
                                 date=predctx.date(),
                                 extra=extras)
         newprednode = repo.commitctx(newctx)
         newpredctx = repo[newprednode]
         dirstate = repo.dirstate
 
         with dirstate.parentchange():
-            _fixdirstate(repo, curctx, newpredctx)
+            _movedirstate(repo, newpredctx)
 
         mapping = {curctx.node(): (newprednode,)}
         scmutil.cleanupnodes(repo, mapping, 'unamend', fixphase=True)