graft: add initial implementation

mercurial/commands.py

@@ -2447,6 +2447,75 b' def forget(ui, repo, *pats, **opts):'
     repo[None].forget(forget)
     return errs
 
+@command('graft',
+    [],
+    _('[OPTION]... REVISION...'))
+def graft(ui, repo, rev, *revs, **opts):
+    '''copy changes from other branches onto the current branch
+
+    This command uses Mercurial's merge logic to copy individual
+    changes from other branches without merging branches in the
+    history graph. This is sometimes known as 'backporting' or
+    'cherry-picking'.
+
+    Changesets that are ancestors of the current revision, that have
+    already been grafted, or that are merges will be skipped.
+
+    Returns 0 on successful completion.
+    '''
+
+    cmdutil.bailifchanged(repo)
+
+    revs = [rev] + list(revs)
+    revs = scmutil.revrange(repo, revs)
+
+    # check for merges
+    for ctx in repo.set('%ld and merge()', revs):
+        ui.warn(_('skipping ungraftable merge revision %s\n') % ctx.rev())
+        revs.remove(ctx.rev())
+    if not revs:
+        return -1
+
+    # check for ancestors of dest branch
+    for ctx in repo.set('::. and %ld', revs):
+        ui.warn(_('skipping ancestor revision %s\n') % ctx.rev())
+        revs.remove(ctx.rev())
+    if not revs:
+        return -1
+
+    # check ancestors for earlier grafts
+    ui.debug('scanning for existing transplants')
+    for ctx in repo.set("::. - ::%ld", revs):
+        n = ctx.extra().get('source')
+        if n and n in repo:
+            r = repo[n].rev()
+            ui.warn(_('skipping already grafted revision %s\n') % r)
+            revs.remove(r)
+    if not revs:
+        return -1
+
+    for ctx in repo.set("%ld", revs):
+        current = repo['.']
+        ui.debug('grafting revision %s', ctx.rev())
+        # perform the graft merge with p1(rev) as 'ancestor'
+        stats = mergemod.update(repo, ctx.node(), True, True, False,
+                             ctx.p1().node())
+        # drop the second merge parent
+        repo.dirstate.setparents(current.node(), nullid)
+        repo.dirstate.write()
+        # fix up dirstate for copies and renames
+        cmdutil.duplicatecopies(repo, ctx.rev(), current.node(), nullid)
+        # report any conflicts
+        if stats and stats[3] > 0:
+            raise util.Abort(_("unresolved conflicts, can't continue"),
+                             hint=_('use hg resolve and hg graft --continue'))
+        # commit
+        extra = {'source': ctx.hex()}
+        repo.commit(text=ctx.description(), user=ctx.user(),
+                    date=ctx.date(), extra=extra)
+
+    return 0
+
 @command('grep',
     [('0', 'print0', None, _('end fields with NUL')),
     ('', 'all', None, _('print all revisions that match')),

tests/test-debugcomplete.t

@@ -17,6 +17,7 b' Show all commands except debug commands'
   diff
   export
   forget
+  graft
   grep
   heads
   help
@@ -242,6 +243,7 b' Show all commands + options'
   debugsub: rev
   debugwalk: include, exclude
   debugwireargs: three, four, five, ssh, remotecmd, insecure
+  graft: 
   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

tests/test-globalopts.t

@@ -296,6 +296,7 b' Testing -h/--help:'
    diff         diff repository (or selected files)
    export       dump the header and diffs for one or more changesets
    forget       forget the specified files on the next commit
+   graft        copy changes from other branches onto the current branch
    grep         search for a pattern in specified files and revisions
    heads        show current repository heads or show branch heads
    help         show help for a given topic or a help overview
@@ -377,6 +378,7 b' Testing -h/--help:'
    diff         diff repository (or selected files)
    export       dump the header and diffs for one or more changesets
    forget       forget the specified files on the next commit
+   graft        copy changes from other branches onto the current branch
    grep         search for a pattern in specified files and revisions
    heads        show current repository heads or show branch heads
    help         show help for a given topic or a help overview

tests/test-help.t

@@ -66,6 +66,7 b' Short help:'
    diff         diff repository (or selected files)
    export       dump the header and diffs for one or more changesets
    forget       forget the specified files on the next commit
+   graft        copy changes from other branches onto the current branch
    grep         search for a pattern in specified files and revisions
    heads        show current repository heads or show branch heads
    help         show help for a given topic or a help overview
@@ -141,6 +142,7 b' Short help:'
    diff         diff repository (or selected files)
    export       dump the header and diffs for one or more changesets
    forget       forget the specified files on the next commit
+   graft        copy changes from other branches onto the current branch
    grep         search for a pattern in specified files and revisions
    heads        show current repository heads or show branch heads
    help         show help for a given topic or a help overview
@@ -626,6 +628,7 b' Test that default list of commands omits'
    diff         diff repository (or selected files)
    export       dump the header and diffs for one or more changesets
    forget       forget the specified files on the next commit
+   graft        copy changes from other branches onto the current branch
    grep         search for a pattern in specified files and revisions
    heads        show current repository heads or show branch heads
    help         show help for a given topic or a help overview