diff hgext/uncommit.py @ 34204:da2f5f19312c

uncommit: move fb-extension to core which uncommits a changeset

uncommit extension in fb-hgext adds a uncommit command which by default
uncommits a changeset and move all the changes to the working directory. If
file names are passed, uncommit moves the changes from those files to the
working directory and left the changeset with remaining committed files.

The uncommit extension in fb-hgext does not creates an empty commit like the one
in evolve extension unless user has specified ui.alllowemptycommit to True.

The test file added is a combination of tests from test-uncommit.t,
test-uncommit-merge.t and test-uncommit-bookmark.t from fb-hgext.

.. feature::

   A new uncommit extension which provides `hg uncommit` using which one can
   uncommit part or all of the changeset. This command undoes the effect of a
   local commit, returning the affected files to their uncommitted state.

Differential Revision: https://phab.mercurial-scm.org/D529

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hgext/uncommit.py	Thu Aug 24 22:55:56 2017 +0530
@@ -0,0 +1,183 @@
+# 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 (
+    commands,
+    context,
+    copies,
+    error,
+    node,
+    obsolete,
+    registrar,
+    scmutil,
+)
+
+cmdtable = {}
+command = registrar.command(cmdtable)
+
+# 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, allowempty):
+    """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
+
+    files = (initialfiles - exclude)
+    # return the p1 so that we don't create an obsmarker later
+    if not files and not allowempty:
+        return ctx.parents()[0].node()
+
+    # Filter copies
+    copied = copies.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, fctx.path(), fctx.data(),
+                                  fctx.islink(),
+                                  fctx.isexec(),
+                                  copied=copied.get(path))
+        return mctx
+
+    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())
+    # phase handling
+    commitphase = ctx.phase()
+    overrides = {('phases', 'new-commit'): commitphase}
+    with repo.ui.configoverride(overrides, 'uncommit'):
+        newid = repo.commitctx(new)
+    return newid
+
+def _uncommitdirstate(repo, oldctx, match):
+    """Fix the dirstate after switching the working directory from
+    oldctx to a copy of oldctx not containing changed files matched by
+    match.
+    """
+    ctx = repo['.']
+    ds = repo.dirstate
+    copies = dict(ds.copies())
+    s = repo.status(oldctx.p1(), 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 = {}
+    for f in (s.modified + s.added):
+        src = oldctx[f].renamed()
+        if src:
+            oldcopies[f] = src[0]
+    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 ctx or dst in ctx or ds[dst] != 'a'):
+            src = None
+        ds.copy(src, dst)
+
+@command('uncommit',
+    [('', 'empty', False, _('allow an empty commit after uncommiting')),
+    ] + commands.walkopts,
+    _('[OPTION]... [FILE]...'))
+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.
+    """
+
+    with repo.wlock(), repo.lock():
+        wctx = repo[None]
+
+        if wctx.parents()[0].node() == node.nullid:
+            raise error.Abort(_("cannot uncommit null changeset"))
+        if len(wctx.parents()) > 1:
+            raise error.Abort(_("cannot uncommit while merging"))
+        old = repo['.']
+        if not old.mutable():
+            raise error.Abort(_('cannot uncommit public changesets'))
+        if len(old.parents()) > 1:
+            raise error.Abort(_("cannot uncommit merge changeset"))
+        allowunstable = obsolete.isenabled(repo, obsolete.allowunstableopt)
+        if not allowunstable and old.children():
+            raise error.Abort(_('cannot uncommit changeset with children'))
+
+        with repo.transaction('uncommit'):
+            match = scmutil.match(old, pats, opts)
+            newid = _commitfiltered(repo, old, match, opts.get('empty'))
+            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()] = ()
+
+            scmutil.cleanupnodes(repo, mapping, 'uncommit')
+
+            with repo.dirstate.parentchange():
+                repo.dirstate.setparents(newid, node.nullid)
+                _uncommitdirstate(repo, old, match)