graft: allow regrafting ancestors with --force (issue3220)

mercurial/commands.py

@@ -3054,6 +3054,7 b' def forget(ui, repo, *pats, **opts):'
      ('c', 'continue', False, _('resume interrupted graft')),
      ('e', 'edit', False, _('invoke editor on commit messages')),
      ('', 'log', None, _('append graft info to log message')),
+     ('f', 'force', False, _('force graft')),
      ('D', 'currentdate', False,
       _('record the current date as commit date')),
      ('U', 'currentuser', False,
@@ -3077,6 +3078,10 b' def graft(ui, repo, *revs, **opts):'
 
       (grafted from CHANGESETHASH)
 
+    If --force is specified, revisions will be grafted even if they
+    are already ancestors of or have been grafted to the destination.
+    This is useful when the revisions have since been backed out.
+
     If a graft merge results in conflicts, the graft process is
     interrupted so that the current merge can be manually resolved.
     Once all conflicts are addressed, the graft process can be
@@ -3151,6 +3156,7 b' def graft(ui, repo, *revs, **opts):'
         return -1
 
     # check for ancestors of dest branch
+    if not opts.get('force'):
     crev = repo['.'].rev()
     ancestors = repo.changelog.ancestors([crev], inclusive=True)
     # Cannot use x.remove(y) on smart set, this has to be a list.

tests/test-completion.t

@@ -257,7 +257,7 b' Show all commands + options'
   debugsuccessorssets: 
   debugwalk: include, exclude
   debugwireargs: three, four, five, ssh, remotecmd, insecure
-  graft: rev, continue, edit, log, currentdate, currentuser, date, user, tool, dry-run
+  graft: rev, continue, edit, log, force, currentdate, currentuser, date, user, tool, dry-run
   grep: print0, all, text, follow, ignore-case, files-with-matches, line-number, rev, user, date, include, exclude
   heads: rev, topo, active, closed, style, template
   help: extension, command, keyword

tests/test-graft.t

@@ -631,3 +631,33 b' graft works on complex revset'
   grafting revision 13
   grafting revision 19
   merging b
+
+graft with --force (still doesn't graft merges)
+
+  $ hg graft 19 0 6
+  skipping ungraftable merge revision 6
+  skipping ancestor revision 0
+  skipping already grafted revision 19 (22 also has origin 2)
+  [255]
+  $ hg graft 19 0 6 --force
+  skipping ungraftable merge revision 6
+  grafting revision 19
+  merging b
+  grafting revision 0
+
+graft --force after backout
+
+  $ echo abc > a
+  $ hg ci -m 28
+  $ hg backout 28
+  reverting a
+  changeset 29:484c03b8dfa4 backs out changeset 28:6c56f0f7f033
+  $ hg graft 28
+  skipping ancestor revision 28
+  [255]
+  $ hg graft 28 --force
+  grafting revision 28
+  merging a
+  $ cat a
+  abc
+