diff hgext/evolve.py @ 1686:474db2d60202

metaedit: add support for folding commits while editing their metadata

This also allows us to accept multiple commits without dealing with the thorny
algorithmic and UI issues of editing multiple commits at once.

Crucially, it is different from 'hg fold --exact' in that it also allows
'folding' a single commit and rewriting its metadata. This is really useful to
have as a single logical operation, for example while preparing a series of
multiple local changesets that will need to be pushed as a single changeset.

--- a/hgext/evolve.py	Mon Apr 25 16:24:42 2016 -0700
+++ b/hgext/evolve.py	Mon Apr 25 16:24:42 2016 -0700
@@ -3160,14 +3160,18 @@
 
 @command('^metaedit',
          [('r', 'rev', [], _("revision to edit")),
+         ('', 'fold', None, _("also fold specified revisions into one")),
          ] + commitopts + commitopts2,
          _('hg metaedit [OPTION]... [-r] [REV]'))
 def metaedit(ui, repo, *revs, **opts):
     """edit commit information
 
-    Edits the commit information for the specified revision. By default, edits
+    Edits the commit information for the specified revisions. By default, edits
     commit information for the working directory parent.
 
+    With --fold, also folds multiple revisions into one if necessary. In this
+    case, the given revisions must form a linear unbroken chain.
+
     .. container:: verbose
 
      Some examples:
@@ -3180,10 +3184,19 @@
 
          hg metaedit --user 'New User <[e-mail]>'
 
+     - Combine all draft revisions that are ancestors of foo but not of @ into
+       one::
+
+         hg metaedit --fold 'draft() and only(foo,@)'
+
+       See :hg:`help phases` for more about draft revisions, and
+       :hg:`help revsets` for more about the `draft()` and `only()` keywords.
     """
     revs = list(revs)
     revs.extend(opts['rev'])
     if not revs:
+        if opts['fold']:
+            raise error.Abort(_('revisions must be specified with --fold'))
         revs = ['.']
 
     wlock = lock = None
@@ -3192,7 +3205,7 @@
         lock = repo.lock()
 
         revs = scmutil.revrange(repo, revs)
-        if len(revs) > 1:
+        if not opts['fold'] and len(revs) > 1:
             # TODO: handle multiple revisions. This is somewhat tricky because
             # if we want to edit a series of commits:
             #
@@ -3201,18 +3214,21 @@
             # we need to rewrite a first, then directly rewrite b on top of the
             # new a, then rewrite c on top of the new b. So we need to handle
             # revisions in topological order.
-            raise error.Abort(_('editing multiple revisions is not '
-                                'currently supported'))
-
-        newunstable = _disallowednewunstable(repo, revs)
-        if newunstable:
-            raise error.Abort(
-                _('cannot edit commit information in the middle of a stack'),
-                hint=_('%s will be affected') % repo[newunstable.first()])
-        if repo.revs("%ld and public()", revs):
-            raise error.Abort(_('cannot edit commit information for public '
-                                'revisions'))
-        root = head = repo[revs.first()]
+            raise error.Abort(_('editing multiple revisions without --fold is '
+                                'not currently supported'))
+
+        if opts['fold']:
+            root, head = _foldcheck(repo, revs)
+        else:
+            newunstable = _disallowednewunstable(repo, revs)
+            if newunstable:
+                raise error.Abort(
+                    _('cannot edit commit information in the middle of a stack'),
+                    hint=_('%s will be affected') % repo[newunstable.first()])
+            if repo.revs("%ld and public()", revs):
+                raise error.Abort(_('cannot edit commit information for public '
+                                    'revisions'))
+            root = head = repo[revs.first()]
 
         wctx = repo[None]
         p1 = wctx.p1()
@@ -3226,7 +3242,12 @@
             if commitopts.get('message') or commitopts.get('logfile'):
                 commitopts['edit'] = False
             else:
-                msgs = [head.description()]
+                if opts['fold']:
+                    msgs = ["HG: This is a fold of %d changesets." % len(allctx)]
+                    msgs += ["HG: Commit message of changeset %s.\n\n%s\n" %
+                             (c.rev(), c.description()) for c in allctx]
+                else:
+                    msgs = [head.description()]
                 commitopts['message'] =  "\n".join(msgs)
                 commitopts['edit'] = True
 
@@ -3248,6 +3269,8 @@
         finally:
             tr.release()
 
+        if opts['fold']:
+            ui.status('%i changesets folded\n' % len(revs))
         if newp1 is not None:
             hg.update(repo, newp1)
     finally: