Mercurial > hg
view mercurial/repair.py @ 13550:1792b8a9422b stable
merge: back out single-parent fast-forward merge
This backs out
changeset: 13158:9e7e24052745
user: Mads Kiilerich <mads@kiilerich.com>
date: Tue Dec 07 03:29:21 2010 +0100
summary: merge: fast-forward merge with descendant
Before named branches, the invariants were:
a) "merges" always have two parents
b) p1 is not linearly related to p2
Adding named branches made (b) problematic, so the above patch was
introduced, which fixed (b) but broke (a).
After discussion, we decided that the invariants should be:
a) "merges" always have two parents
b) p1 is not linearly related to p2 OR p1 and p2 are on different branches
author | Matt Mackall <mpm@selenic.com> |
---|---|
date | Mon, 07 Mar 2011 15:03:10 -0600 |
parents | ee01d9d84115 |
children | ffd370aa050b |
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# repair.py - functions for repository repair for mercurial # # Copyright 2005, 2006 Chris Mason <mason@suse.com> # Copyright 2007 Matt Mackall # # This software may be used and distributed according to the terms of the # GNU General Public License version 2 or any later version. import changegroup, bookmarks from node import nullrev, short from i18n import _ import os def _bundle(repo, bases, heads, node, suffix, extranodes=None, compress=True): """create a bundle with the specified revisions as a backup""" cg = repo.changegroupsubset(bases, heads, 'strip', extranodes) backupdir = repo.join("strip-backup") if not os.path.isdir(backupdir): os.mkdir(backupdir) name = os.path.join(backupdir, "%s-%s.hg" % (short(node), suffix)) if compress: bundletype = "HG10BZ" else: bundletype = "HG10UN" return changegroup.writebundle(cg, name, bundletype) def _collectfiles(repo, striprev): """find out the filelogs affected by the strip""" files = set() for x in xrange(striprev, len(repo)): files.update(repo[x].files()) return sorted(files) def _collectextranodes(repo, files, link): """return the nodes that have to be saved before the strip""" def collectone(cl, revlog): extra = [] startrev = count = len(revlog) # find the truncation point of the revlog for i in xrange(count): lrev = revlog.linkrev(i) if lrev >= link: startrev = i + 1 break # see if any revision after that point has a linkrev less than link # (we have to manually save these guys) for i in xrange(startrev, count): node = revlog.node(i) lrev = revlog.linkrev(i) if lrev < link: extra.append((node, cl.node(lrev))) return extra extranodes = {} cl = repo.changelog extra = collectone(cl, repo.manifest) if extra: extranodes[1] = extra for fname in files: f = repo.file(fname) extra = collectone(cl, f) if extra: extranodes[fname] = extra return extranodes def strip(ui, repo, node, backup="all"): cl = repo.changelog # TODO delete the undo files, and handle undo of merge sets striprev = cl.rev(node) keeppartialbundle = backup == 'strip' # Some revisions with rev > striprev may not be descendants of striprev. # We have to find these revisions and put them in a bundle, so that # we can restore them after the truncations. # To create the bundle we use repo.changegroupsubset which requires # the list of heads and bases of the set of interesting revisions. # (head = revision in the set that has no descendant in the set; # base = revision in the set that has no ancestor in the set) tostrip = set((striprev,)) saveheads = set() savebases = [] for r in xrange(striprev + 1, len(cl)): parents = cl.parentrevs(r) if parents[0] in tostrip or parents[1] in tostrip: # r is a descendant of striprev tostrip.add(r) # if this is a merge and one of the parents does not descend # from striprev, mark that parent as a savehead. if parents[1] != nullrev: for p in parents: if p not in tostrip and p > striprev: saveheads.add(p) else: # if no parents of this revision will be stripped, mark it as # a savebase if parents[0] < striprev and parents[1] < striprev: savebases.append(cl.node(r)) saveheads.difference_update(parents) saveheads.add(r) bm = repo._bookmarks updatebm = [] for m in bm: rev = repo[bm[m]].rev() if rev in tostrip: updatebm.append(m) saveheads = [cl.node(r) for r in saveheads] files = _collectfiles(repo, striprev) extranodes = _collectextranodes(repo, files, striprev) # create a changegroup for all the branches we need to keep backupfile = None if backup == "all": backupfile = _bundle(repo, [node], cl.heads(), node, 'backup') repo.ui.status(_("saved backup bundle to %s\n") % backupfile) if saveheads or extranodes: # do not compress partial bundle if we remove it from disk later chgrpfile = _bundle(repo, savebases, saveheads, node, 'temp', extranodes=extranodes, compress=keeppartialbundle) mfst = repo.manifest tr = repo.transaction("strip") offset = len(tr.entries) try: tr.startgroup() cl.strip(striprev, tr) mfst.strip(striprev, tr) for fn in files: repo.file(fn).strip(striprev, tr) tr.endgroup() try: for i in xrange(offset, len(tr.entries)): file, troffset, ignore = tr.entries[i] repo.sopener(file, 'a').truncate(troffset) tr.close() except: tr.abort() raise if saveheads or extranodes: ui.note(_("adding branch\n")) f = open(chgrpfile, "rb") gen = changegroup.readbundle(f, chgrpfile) if not repo.ui.verbose: # silence internal shuffling chatter repo.ui.pushbuffer() repo.addchangegroup(gen, 'strip', 'bundle:' + chgrpfile, True) if not repo.ui.verbose: repo.ui.popbuffer() f.close() if not keeppartialbundle: os.unlink(chgrpfile) for m in updatebm: bm[m] = repo['.'].node() bookmarks.write(repo) except: if backupfile: ui.warn(_("strip failed, full bundle stored in '%s'\n") % backupfile) elif saveheads: ui.warn(_("strip failed, partial bundle stored in '%s'\n") % chgrpfile) raise repo.destroyed()