convert: handle LookupError in mercurial_source.lookuprev()

This is in line with the documentation on the base class method, and is related
to issue4496 (but doesn't fix the reporter's problem of not mangling other data
that matches a revision pattern).  Now instead of aborting when there is an
ambiguous source rev, it simply won't update the commit comment.  A warning
message might be nice, but a None return masks whether the problem was no
matching revision, or more than one.

The only other caller of this is the logic that converts tags, but those are
never ambiguous since they are always 40 characters.

A test isn't feasible because there simply aren't enough commits in the test
suite repos to have an ambiguous identifier that is at least 6 characters long,
and it would be too easy for the ambiguity to disappear when unrelated changes
are made.  Instead, I simply ran 'hg --traceback log -r c' on the hg repo, and
handled the error it threw.

hgext/convert/hg.py

@@ -1,478 +1,478 b''
 # hg.py - hg backend for convert extension
 #
 #  Copyright 2005-2009 Matt Mackall <[e-mail]> and others
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 # Notes for hg->hg conversion:
 #
 # * Old versions of Mercurial didn't trim the whitespace from the ends
 #   of commit messages, but new versions do.  Changesets created by
 #   those older versions, then converted, may thus have different
 #   hashes for changesets that are otherwise identical.
 #
 # * Using "--config convert.hg.saverev=true" will make the source
 #   identifier to be stored in the converted revision. This will cause
 #   the converted revision to have a different identity than the
 #   source.
 
 
 import os, time, cStringIO
 from mercurial.i18n import _
 from mercurial.node import bin, hex, nullid
 from mercurial import hg, util, context, bookmarks, error, scmutil, exchange
 
 from common import NoRepo, commit, converter_source, converter_sink
 
 import re
 sha1re = re.compile(r'\b[0-9a-f]{6,40}\b')
 
 class mercurial_sink(converter_sink):
     def __init__(self, ui, path):
         converter_sink.__init__(self, ui, path)
         self.branchnames = ui.configbool('convert', 'hg.usebranchnames', True)
         self.clonebranches = ui.configbool('convert', 'hg.clonebranches', False)
         self.tagsbranch = ui.config('convert', 'hg.tagsbranch', 'default')
         self.lastbranch = None
         if os.path.isdir(path) and len(os.listdir(path)) > 0:
             try:
                 self.repo = hg.repository(self.ui, path)
                 if not self.repo.local():
                     raise NoRepo(_('%s is not a local Mercurial repository')
                                  % path)
             except error.RepoError, err:
                 ui.traceback()
                 raise NoRepo(err.args[0])
         else:
             try:
                 ui.status(_('initializing destination %s repository\n') % path)
                 self.repo = hg.repository(self.ui, path, create=True)
                 if not self.repo.local():
                     raise NoRepo(_('%s is not a local Mercurial repository')
                                  % path)
                 self.created.append(path)
             except error.RepoError:
                 ui.traceback()
                 raise NoRepo(_("could not create hg repository %s as sink")
                              % path)
         self.lock = None
         self.wlock = None
         self.filemapmode = False
 
     def before(self):
         self.ui.debug('run hg sink pre-conversion action\n')
         self.wlock = self.repo.wlock()
         self.lock = self.repo.lock()
 
     def after(self):
         self.ui.debug('run hg sink post-conversion action\n')
         if self.lock:
             self.lock.release()
         if self.wlock:
             self.wlock.release()
 
     def revmapfile(self):
         return self.repo.join("shamap")
 
     def authorfile(self):
         return self.repo.join("authormap")
 
     def setbranch(self, branch, pbranches):
         if not self.clonebranches:
             return
 
         setbranch = (branch != self.lastbranch)
         self.lastbranch = branch
         if not branch:
             branch = 'default'
         pbranches = [(b[0], b[1] and b[1] or 'default') for b in pbranches]
         pbranch = pbranches and pbranches[0][1] or 'default'
 
         branchpath = os.path.join(self.path, branch)
         if setbranch:
             self.after()
             try:
                 self.repo = hg.repository(self.ui, branchpath)
             except Exception:
                 self.repo = hg.repository(self.ui, branchpath, create=True)
             self.before()
 
         # pbranches may bring revisions from other branches (merge parents)
         # Make sure we have them, or pull them.
         missings = {}
         for b in pbranches:
             try:
                 self.repo.lookup(b[0])
             except Exception:
                 missings.setdefault(b[1], []).append(b[0])
 
         if missings:
             self.after()
             for pbranch, heads in sorted(missings.iteritems()):
                 pbranchpath = os.path.join(self.path, pbranch)
                 prepo = hg.peer(self.ui, {}, pbranchpath)
                 self.ui.note(_('pulling from %s into %s\n') % (pbranch, branch))
                 exchange.pull(self.repo, prepo,
                               [prepo.lookup(h) for h in heads])
             self.before()
 
     def _rewritetags(self, source, revmap, data):
         fp = cStringIO.StringIO()
         for line in data.splitlines():
             s = line.split(' ', 1)
             if len(s) != 2:
                 continue
             revid = revmap.get(source.lookuprev(s[0]))
             if not revid:
                 continue
             fp.write('%s %s\n' % (revid, s[1]))
         return fp.getvalue()
 
     def putcommit(self, files, copies, parents, commit, source, revmap, full):
         files = dict(files)
         def getfilectx(repo, memctx, f):
             try:
                 v = files[f]
             except KeyError:
                 return None
             data, mode = source.getfile(f, v)
             if data is None:
                 return None
             if f == '.hgtags':
                 data = self._rewritetags(source, revmap, data)
             return context.memfilectx(self.repo, f, data, 'l' in mode,
                                       'x' in mode, copies.get(f))
 
         pl = []
         for p in parents:
             if p not in pl:
                 pl.append(p)
         parents = pl
         nparents = len(parents)
         if self.filemapmode and nparents == 1:
             m1node = self.repo.changelog.read(bin(parents[0]))[0]
             parent = parents[0]
 
         if len(parents) < 2:
             parents.append(nullid)
         if len(parents) < 2:
             parents.append(nullid)
         p2 = parents.pop(0)
 
         text = commit.desc
 
         sha1s = re.findall(sha1re, text)
         for sha1 in sha1s:
             oldrev = source.lookuprev(sha1)
             newrev = revmap.get(oldrev)
             if newrev is not None:
                 text = text.replace(sha1, newrev[:len(sha1)])
 
         extra = commit.extra.copy()
 
         for label in ('source', 'transplant_source', 'rebase_source'):
             node = extra.get(label)
 
             if node is None:
                 continue
 
             # Only transplant stores its reference in binary
             if label == 'transplant_source':
                 node = hex(node)
 
             newrev = revmap.get(node)
             if newrev is not None:
                 if label == 'transplant_source':
                     newrev = bin(newrev)
 
                 extra[label] = newrev
 
         if self.branchnames and commit.branch:
             extra['branch'] = commit.branch
         if commit.rev:
             extra['convert_revision'] = commit.rev
 
         while parents:
             p1 = p2
             p2 = parents.pop(0)
             fileset = set(files)
             if full:
                 fileset.update(self.repo[p1])
                 fileset.update(self.repo[p2])
             ctx = context.memctx(self.repo, (p1, p2), text, fileset,
                                  getfilectx, commit.author, commit.date, extra)
             self.repo.commitctx(ctx)
             text = "(octopus merge fixup)\n"
             p2 = hex(self.repo.changelog.tip())
 
         if self.filemapmode and nparents == 1:
             man = self.repo.manifest
             mnode = self.repo.changelog.read(bin(p2))[0]
             closed = 'close' in commit.extra
             if not closed and not man.cmp(m1node, man.revision(mnode)):
                 self.ui.status(_("filtering out empty revision\n"))
                 self.repo.rollback(force=True)
                 return parent
         return p2
 
     def puttags(self, tags):
         try:
             parentctx = self.repo[self.tagsbranch]
             tagparent = parentctx.node()
         except error.RepoError:
             parentctx = None
             tagparent = nullid
 
         oldlines = set()
         for branch, heads in self.repo.branchmap().iteritems():
             for h in heads:
                 if '.hgtags' in self.repo[h]:
                     oldlines.update(
                         set(self.repo[h]['.hgtags'].data().splitlines(True)))
         oldlines = sorted(list(oldlines))
 
         newlines = sorted([("%s %s\n" % (tags[tag], tag)) for tag in tags])
         if newlines == oldlines:
             return None, None
 
         # if the old and new tags match, then there is nothing to update
         oldtags = set()
         newtags = set()
         for line in oldlines:
             s = line.strip().split(' ', 1)
             if len(s) != 2:
                 continue
             oldtags.add(s[1])
         for line in newlines:
             s = line.strip().split(' ', 1)
             if len(s) != 2:
                 continue
             if s[1] not in oldtags:
                 newtags.add(s[1].strip())
 
         if not newtags:
             return None, None
 
         data = "".join(newlines)
         def getfilectx(repo, memctx, f):
             return context.memfilectx(repo, f, data, False, False, None)
 
         self.ui.status(_("updating tags\n"))
         date = "%s 0" % int(time.mktime(time.gmtime()))
         extra = {'branch': self.tagsbranch}
         ctx = context.memctx(self.repo, (tagparent, None), "update tags",
                              [".hgtags"], getfilectx, "convert-repo", date,
                              extra)
         self.repo.commitctx(ctx)
         return hex(self.repo.changelog.tip()), hex(tagparent)
 
     def setfilemapmode(self, active):
         self.filemapmode = active
 
     def putbookmarks(self, updatedbookmark):
         if not len(updatedbookmark):
             return
 
         self.ui.status(_("updating bookmarks\n"))
         destmarks = self.repo._bookmarks
         for bookmark in updatedbookmark:
             destmarks[bookmark] = bin(updatedbookmark[bookmark])
         destmarks.write()
 
     def hascommitfrommap(self, rev):
         # the exact semantics of clonebranches is unclear so we can't say no
         return rev in self.repo or self.clonebranches
 
     def hascommitforsplicemap(self, rev):
         if rev not in self.repo and self.clonebranches:
             raise util.Abort(_('revision %s not found in destination '
                                'repository (lookups with clonebranches=true '
                                'are not implemented)') % rev)
         return rev in self.repo
 
 class mercurial_source(converter_source):
     def __init__(self, ui, path, rev=None):
         converter_source.__init__(self, ui, path, rev)
         self.ignoreerrors = ui.configbool('convert', 'hg.ignoreerrors', False)
         self.ignored = set()
         self.saverev = ui.configbool('convert', 'hg.saverev', False)
         try:
             self.repo = hg.repository(self.ui, path)
             # try to provoke an exception if this isn't really a hg
             # repo, but some other bogus compatible-looking url
             if not self.repo.local():
                 raise error.RepoError
         except error.RepoError:
             ui.traceback()
             raise NoRepo(_("%s is not a local Mercurial repository") % path)
         self.lastrev = None
         self.lastctx = None
         self._changescache = None, None
         self.convertfp = None
         # Restrict converted revisions to startrev descendants
         startnode = ui.config('convert', 'hg.startrev')
         hgrevs = ui.config('convert', 'hg.revs')
         if hgrevs is None:
             if startnode is not None:
                 try:
                     startnode = self.repo.lookup(startnode)
                 except error.RepoError:
                     raise util.Abort(_('%s is not a valid start revision')
                                      % startnode)
                 startrev = self.repo.changelog.rev(startnode)
                 children = {startnode: 1}
                 for r in self.repo.changelog.descendants([startrev]):
                     children[self.repo.changelog.node(r)] = 1
                 self.keep = children.__contains__
             else:
                 self.keep = util.always
             if rev:
                 self._heads = [self.repo[rev].node()]
             else:
                 self._heads = self.repo.heads()
         else:
             if rev or startnode is not None:
                 raise util.Abort(_('hg.revs cannot be combined with '
                                    'hg.startrev or --rev'))
             nodes = set()
             parents = set()
             for r in scmutil.revrange(self.repo, [hgrevs]):
                 ctx = self.repo[r]
                 nodes.add(ctx.node())
                 parents.update(p.node() for p in ctx.parents())
             self.keep = nodes.__contains__
             self._heads = nodes - parents
 
     def changectx(self, rev):
         if self.lastrev != rev:
             self.lastctx = self.repo[rev]
             self.lastrev = rev
         return self.lastctx
 
     def parents(self, ctx):
         return [p for p in ctx.parents() if p and self.keep(p.node())]
 
     def getheads(self):
         return [hex(h) for h in self._heads if self.keep(h)]
 
     def getfile(self, name, rev):
         try:
             fctx = self.changectx(rev)[name]
             return fctx.data(), fctx.flags()
         except error.LookupError:
             return None, None
 
     def getchanges(self, rev, full):
         ctx = self.changectx(rev)
         parents = self.parents(ctx)
         if full or not parents:
             files = copyfiles = ctx.manifest()
         if parents:
             if self._changescache[0] == rev:
                 m, a, r = self._changescache[1]
             else:
                 m, a, r = self.repo.status(parents[0].node(), ctx.node())[:3]
             if not full:
                 files = m + a + r
             copyfiles = m + a
         # getcopies() is also run for roots and before filtering so missing
         # revlogs are detected early
         copies = self.getcopies(ctx, parents, copyfiles)
         changes = [(f, rev) for f in files if f not in self.ignored]
         changes.sort()
         return changes, copies
 
     def getcopies(self, ctx, parents, files):
         copies = {}
         for name in files:
             if name in self.ignored:
                 continue
             try:
                 copysource, _copynode = ctx.filectx(name).renamed()
                 if copysource in self.ignored:
                     continue
                 # Ignore copy sources not in parent revisions
                 found = False
                 for p in parents:
                     if copysource in p:
                         found = True
                         break
                 if not found:
                     continue
                 copies[name] = copysource
             except TypeError:
                 pass
             except error.LookupError, e:
                 if not self.ignoreerrors:
                     raise
                 self.ignored.add(name)
                 self.ui.warn(_('ignoring: %s\n') % e)
         return copies
 
     def getcommit(self, rev):
         ctx = self.changectx(rev)
         parents = [p.hex() for p in self.parents(ctx)]
         if self.saverev:
             crev = rev
         else:
             crev = None
         return commit(author=ctx.user(),
                       date=util.datestr(ctx.date(), '%Y-%m-%d %H:%M:%S %1%2'),
                       desc=ctx.description(), rev=crev, parents=parents,
                       branch=ctx.branch(), extra=ctx.extra(),
                       sortkey=ctx.rev())
 
     def gettags(self):
         # This will get written to .hgtags, filter non global tags out.
         tags = [t for t in self.repo.tagslist()
                 if self.repo.tagtype(t[0]) == 'global']
         return dict([(name, hex(node)) for name, node in tags
                      if self.keep(node)])
 
     def getchangedfiles(self, rev, i):
         ctx = self.changectx(rev)
         parents = self.parents(ctx)
         if not parents and i is None:
             i = 0
             changes = [], ctx.manifest().keys(), []
         else:
             i = i or 0
             changes = self.repo.status(parents[i].node(), ctx.node())[:3]
         changes = [[f for f in l if f not in self.ignored] for l in changes]
 
         if i == 0:
             self._changescache = (rev, changes)
 
         return changes[0] + changes[1] + changes[2]
 
     def converted(self, rev, destrev):
         if self.convertfp is None:
             self.convertfp = open(self.repo.join('shamap'), 'a')
         self.convertfp.write('%s %s\n' % (destrev, rev))
         self.convertfp.flush()
 
     def before(self):
         self.ui.debug('run hg source pre-conversion action\n')
 
     def after(self):
         self.ui.debug('run hg source post-conversion action\n')
 
     def hasnativeorder(self):
         return True
 
     def hasnativeclose(self):
         return True
 
     def lookuprev(self, rev):
         try:
             return hex(self.repo.lookup(rev))
-        except error.RepoError:
+        except (error.RepoError, error.LookupError):
             return None
 
     def getbookmarks(self):
         return bookmarks.listbookmarks(self.repo)
 
     def checkrevformat(self, revstr, mapname='splicemap'):
         """ Mercurial, revision string is a 40 byte hex """
         self.checkhexformat(revstr, mapname)