diffordiffstat: avoid looking up contexts twice

I'm not worried about performance; this is just simpler.

Differential Revision: https://phab.mercurial-scm.org/D5890

mercurial/logcmdutil.py

@@ -1,914 +1,913 b''
 # logcmdutil.py - utility for log-like commands
 #
 # Copyright 2005-2007 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms of the
 # GNU General Public License version 2 or any later version.
 
 from __future__ import absolute_import
 
 import itertools
 import os
 
 from .i18n import _
 from .node import (
     nullid,
     wdirid,
     wdirrev,
 )
 
 from . import (
     dagop,
     error,
     formatter,
     graphmod,
     match as matchmod,
     mdiff,
     patch,
     pathutil,
     pycompat,
     revset,
     revsetlang,
     scmutil,
     smartset,
     templatekw,
     templater,
     util,
 )
 from .utils import (
     dateutil,
     stringutil,
 )
 
 def getlimit(opts):
     """get the log limit according to option -l/--limit"""
     limit = opts.get('limit')
     if limit:
         try:
             limit = int(limit)
         except ValueError:
             raise error.Abort(_('limit must be a positive integer'))
         if limit <= 0:
             raise error.Abort(_('limit must be positive'))
     else:
         limit = None
     return limit
 
 def diffordiffstat(ui, repo, diffopts, node1, node2, match,
                    changes=None, stat=False, fp=None, graphwidth=0,
                    prefix='', root='', listsubrepos=False, hunksfilterfn=None):
     '''show diff or diffstat.'''
+    ctx1 = repo[node1]
+    ctx2 = repo[node2]
     if root:
         relroot = pathutil.canonpath(repo.root, repo.getcwd(), root)
     else:
         relroot = ''
     if relroot != '':
         # XXX relative roots currently don't work if the root is within a
         # subrepo
         uirelroot = match.uipath(relroot)
         relroot += '/'
         for matchroot in match.files():
             if not matchroot.startswith(relroot):
                 ui.warn(_('warning: %s not inside relative root %s\n') % (
                     match.uipath(matchroot), uirelroot))
 
     if stat:
         diffopts = diffopts.copy(context=0, noprefix=False)
         width = 80
         if not ui.plain():
             width = ui.termwidth() - graphwidth
 
-    chunks = repo[node2].diff(repo[node1], match, changes, opts=diffopts,
-                              prefix=prefix, relroot=relroot,
-                              hunksfilterfn=hunksfilterfn)
+    chunks = ctx2.diff(ctx1, match, changes, opts=diffopts, prefix=prefix,
+                       relroot=relroot, hunksfilterfn=hunksfilterfn)
 
     if fp is not None or ui.canwritewithoutlabels():
         out = fp or ui
         if stat:
             chunks = [patch.diffstat(util.iterlines(chunks), width=width)]
         for chunk in util.filechunkiter(util.chunkbuffer(chunks)):
             out.write(chunk)
     else:
         if stat:
             chunks = patch.diffstatui(util.iterlines(chunks), width=width)
         else:
             chunks = patch.difflabel(lambda chunks, **kwargs: chunks, chunks,
                                      opts=diffopts)
         if ui.canbatchlabeledwrites():
             def gen():
                 for chunk, label in chunks:
                     yield ui.label(chunk, label=label)
             for chunk in util.filechunkiter(util.chunkbuffer(gen())):
                 ui.write(chunk)
         else:
             for chunk, label in chunks:
                 ui.write(chunk, label=label)
 
     if listsubrepos:
-        ctx1 = repo[node1]
-        ctx2 = repo[node2]
         for subpath, sub in scmutil.itersubrepos(ctx1, ctx2):
             tempnode2 = node2
             try:
                 if node2 is not None:
                     tempnode2 = ctx2.substate[subpath][1]
             except KeyError:
                 # A subrepo that existed in node1 was deleted between node1 and
                 # node2 (inclusive). Thus, ctx2's substate won't contain that
                 # subpath. The best we can do is to ignore it.
                 tempnode2 = None
             submatch = matchmod.subdirmatcher(subpath, match)
             sub.diff(ui, diffopts, tempnode2, submatch, changes=changes,
                      stat=stat, fp=fp, prefix=prefix)
 
 class changesetdiffer(object):
     """Generate diff of changeset with pre-configured filtering functions"""
 
     def _makefilematcher(self, ctx):
         return scmutil.matchall(ctx.repo())
 
     def _makehunksfilter(self, ctx):
         return None
 
     def showdiff(self, ui, ctx, diffopts, graphwidth=0, stat=False):
         repo = ctx.repo()
         node = ctx.node()
         prev = ctx.p1().node()
         diffordiffstat(ui, repo, diffopts, prev, node,
                        match=self._makefilematcher(ctx), stat=stat,
                        graphwidth=graphwidth,
                        hunksfilterfn=self._makehunksfilter(ctx))
 
 def changesetlabels(ctx):
     labels = ['log.changeset', 'changeset.%s' % ctx.phasestr()]
     if ctx.obsolete():
         labels.append('changeset.obsolete')
     if ctx.isunstable():
         labels.append('changeset.unstable')
         for instability in ctx.instabilities():
             labels.append('instability.%s' % instability)
     return ' '.join(labels)
 
 class changesetprinter(object):
     '''show changeset information when templating not requested.'''
 
     def __init__(self, ui, repo, differ=None, diffopts=None, buffered=False):
         self.ui = ui
         self.repo = repo
         self.buffered = buffered
         self._differ = differ or changesetdiffer()
         self._diffopts = patch.diffallopts(ui, diffopts)
         self._includestat = diffopts and diffopts.get('stat')
         self._includediff = diffopts and diffopts.get('patch')
         self.header = {}
         self.hunk = {}
         self.lastheader = None
         self.footer = None
         self._columns = templatekw.getlogcolumns()
 
     def flush(self, ctx):
         rev = ctx.rev()
         if rev in self.header:
             h = self.header[rev]
             if h != self.lastheader:
                 self.lastheader = h
                 self.ui.write(h)
             del self.header[rev]
         if rev in self.hunk:
             self.ui.write(self.hunk[rev])
             del self.hunk[rev]
 
     def close(self):
         if self.footer:
             self.ui.write(self.footer)
 
     def show(self, ctx, copies=None, **props):
         props = pycompat.byteskwargs(props)
         if self.buffered:
             self.ui.pushbuffer(labeled=True)
             self._show(ctx, copies, props)
             self.hunk[ctx.rev()] = self.ui.popbuffer()
         else:
             self._show(ctx, copies, props)
 
     def _show(self, ctx, copies, props):
         '''show a single changeset or file revision'''
         changenode = ctx.node()
         graphwidth = props.get('graphwidth', 0)
 
         if self.ui.quiet:
             self.ui.write("%s\n" % scmutil.formatchangeid(ctx),
                           label='log.node')
             return
 
         columns = self._columns
         self.ui.write(columns['changeset'] % scmutil.formatchangeid(ctx),
                       label=changesetlabels(ctx))
 
         # branches are shown first before any other names due to backwards
         # compatibility
         branch = ctx.branch()
         # don't show the default branch name
         if branch != 'default':
             self.ui.write(columns['branch'] % branch, label='log.branch')
 
         for nsname, ns in self.repo.names.iteritems():
             # branches has special logic already handled above, so here we just
             # skip it
             if nsname == 'branches':
                 continue
             # we will use the templatename as the color name since those two
             # should be the same
             for name in ns.names(self.repo, changenode):
                 self.ui.write(ns.logfmt % name,
                               label='log.%s' % ns.colorname)
         if self.ui.debugflag:
             self.ui.write(columns['phase'] % ctx.phasestr(), label='log.phase')
         for pctx in scmutil.meaningfulparents(self.repo, ctx):
             label = 'log.parent changeset.%s' % pctx.phasestr()
             self.ui.write(columns['parent'] % scmutil.formatchangeid(pctx),
                           label=label)
 
         if self.ui.debugflag:
             mnode = ctx.manifestnode()
             if mnode is None:
                 mnode = wdirid
                 mrev = wdirrev
             else:
                 mrev = self.repo.manifestlog.rev(mnode)
             self.ui.write(columns['manifest']
                           % scmutil.formatrevnode(self.ui, mrev, mnode),
                           label='ui.debug log.manifest')
         self.ui.write(columns['user'] % ctx.user(), label='log.user')
         self.ui.write(columns['date'] % dateutil.datestr(ctx.date()),
                       label='log.date')
 
         if ctx.isunstable():
             instabilities = ctx.instabilities()
             self.ui.write(columns['instability'] % ', '.join(instabilities),
                           label='log.instability')
 
         elif ctx.obsolete():
             self._showobsfate(ctx)
 
         self._exthook(ctx)
 
         if self.ui.debugflag:
             files = ctx.p1().status(ctx)[:3]
             for key, value in zip(['files', 'files+', 'files-'], files):
                 if value:
                     self.ui.write(columns[key] % " ".join(value),
                                   label='ui.debug log.files')
         elif ctx.files() and self.ui.verbose:
             self.ui.write(columns['files'] % " ".join(ctx.files()),
                           label='ui.note log.files')
         if copies and self.ui.verbose:
             copies = ['%s (%s)' % c for c in copies]
             self.ui.write(columns['copies'] % ' '.join(copies),
                           label='ui.note log.copies')
 
         extra = ctx.extra()
         if extra and self.ui.debugflag:
             for key, value in sorted(extra.items()):
                 self.ui.write(columns['extra']
                               % (key, stringutil.escapestr(value)),
                               label='ui.debug log.extra')
 
         description = ctx.description().strip()
         if description:
             if self.ui.verbose:
                 self.ui.write(_("description:\n"),
                               label='ui.note log.description')
                 self.ui.write(description,
                               label='ui.note log.description')
                 self.ui.write("\n\n")
             else:
                 self.ui.write(columns['summary'] % description.splitlines()[0],
                               label='log.summary')
         self.ui.write("\n")
 
         self._showpatch(ctx, graphwidth)
 
     def _showobsfate(self, ctx):
         # TODO: do not depend on templater
         tres = formatter.templateresources(self.repo.ui, self.repo)
         t = formatter.maketemplater(self.repo.ui, '{join(obsfate, "\n")}',
                                     defaults=templatekw.keywords,
                                     resources=tres)
         obsfate = t.renderdefault({'ctx': ctx}).splitlines()
 
         if obsfate:
             for obsfateline in obsfate:
                 self.ui.write(self._columns['obsolete'] % obsfateline,
                               label='log.obsfate')
 
     def _exthook(self, ctx):
         '''empty method used by extension as a hook point
         '''
 
     def _showpatch(self, ctx, graphwidth=0):
         if self._includestat:
             self._differ.showdiff(self.ui, ctx, self._diffopts,
                                   graphwidth, stat=True)
         if self._includestat and self._includediff:
             self.ui.write("\n")
         if self._includediff:
             self._differ.showdiff(self.ui, ctx, self._diffopts,
                                   graphwidth, stat=False)
         if self._includestat or self._includediff:
             self.ui.write("\n")
 
 class changesetformatter(changesetprinter):
     """Format changeset information by generic formatter"""
 
     def __init__(self, ui, repo, fm, differ=None, diffopts=None,
                  buffered=False):
         changesetprinter.__init__(self, ui, repo, differ, diffopts, buffered)
         self._diffopts = patch.difffeatureopts(ui, diffopts, git=True)
         self._fm = fm
 
     def close(self):
         self._fm.end()
 
     def _show(self, ctx, copies, props):
         '''show a single changeset or file revision'''
         fm = self._fm
         fm.startitem()
         fm.context(ctx=ctx)
         fm.data(rev=scmutil.intrev(ctx),
                 node=fm.hexfunc(scmutil.binnode(ctx)))
 
         if self.ui.quiet:
             return
 
         fm.data(branch=ctx.branch(),
                 phase=ctx.phasestr(),
                 user=ctx.user(),
                 date=fm.formatdate(ctx.date()),
                 desc=ctx.description(),
                 bookmarks=fm.formatlist(ctx.bookmarks(), name='bookmark'),
                 tags=fm.formatlist(ctx.tags(), name='tag'),
                 parents=fm.formatlist([fm.hexfunc(c.node())
                                        for c in ctx.parents()], name='node'))
 
         if self.ui.debugflag:
             fm.data(manifest=fm.hexfunc(ctx.manifestnode() or wdirid),
                     extra=fm.formatdict(ctx.extra()))
 
             files = ctx.p1().status(ctx)
             fm.data(modified=fm.formatlist(files[0], name='file'),
                     added=fm.formatlist(files[1], name='file'),
                     removed=fm.formatlist(files[2], name='file'))
 
         elif self.ui.verbose:
             fm.data(files=fm.formatlist(ctx.files(), name='file'))
             if copies:
                 fm.data(copies=fm.formatdict(copies,
                                              key='name', value='source'))
 
         if self._includestat:
             self.ui.pushbuffer()
             self._differ.showdiff(self.ui, ctx, self._diffopts, stat=True)
             fm.data(diffstat=self.ui.popbuffer())
         if self._includediff:
             self.ui.pushbuffer()
             self._differ.showdiff(self.ui, ctx, self._diffopts, stat=False)
             fm.data(diff=self.ui.popbuffer())
 
 class changesettemplater(changesetprinter):
     '''format changeset information.
 
     Note: there are a variety of convenience functions to build a
     changesettemplater for common cases. See functions such as:
     maketemplater, changesetdisplayer, buildcommittemplate, or other
     functions that use changesest_templater.
     '''
 
     # Arguments before "buffered" used to be positional. Consider not
     # adding/removing arguments before "buffered" to not break callers.
     def __init__(self, ui, repo, tmplspec, differ=None, diffopts=None,
                  buffered=False):
         changesetprinter.__init__(self, ui, repo, differ, diffopts, buffered)
         # tres is shared with _graphnodeformatter()
         self._tresources = tres = formatter.templateresources(ui, repo)
         self.t = formatter.loadtemplater(ui, tmplspec,
                                          defaults=templatekw.keywords,
                                          resources=tres,
                                          cache=templatekw.defaulttempl)
         self._counter = itertools.count()
 
         self._tref = tmplspec.ref
         self._parts = {'header': '', 'footer': '',
                        tmplspec.ref: tmplspec.ref,
                        'docheader': '', 'docfooter': '',
                        'separator': ''}
         if tmplspec.mapfile:
             # find correct templates for current mode, for backward
             # compatibility with 'log -v/-q/--debug' using a mapfile
             tmplmodes = [
                 (True, ''),
                 (self.ui.verbose, '_verbose'),
                 (self.ui.quiet, '_quiet'),
                 (self.ui.debugflag, '_debug'),
             ]
             for mode, postfix in tmplmodes:
                 for t in self._parts:
                     cur = t + postfix
                     if mode and cur in self.t:
                         self._parts[t] = cur
         else:
             partnames = [p for p in self._parts.keys() if p != tmplspec.ref]
             m = formatter.templatepartsmap(tmplspec, self.t, partnames)
             self._parts.update(m)
 
         if self._parts['docheader']:
             self.ui.write(self.t.render(self._parts['docheader'], {}))
 
     def close(self):
         if self._parts['docfooter']:
             if not self.footer:
                 self.footer = ""
             self.footer += self.t.render(self._parts['docfooter'], {})
         return super(changesettemplater, self).close()
 
     def _show(self, ctx, copies, props):
         '''show a single changeset or file revision'''
         props = props.copy()
         props['ctx'] = ctx
         props['index'] = index = next(self._counter)
         props['revcache'] = {'copies': copies}
         graphwidth = props.get('graphwidth', 0)
 
         # write separator, which wouldn't work well with the header part below
         # since there's inherently a conflict between header (across items) and
         # separator (per item)
         if self._parts['separator'] and index > 0:
             self.ui.write(self.t.render(self._parts['separator'], {}))
 
         # write header
         if self._parts['header']:
             h = self.t.render(self._parts['header'], props)
             if self.buffered:
                 self.header[ctx.rev()] = h
             else:
                 if self.lastheader != h:
                     self.lastheader = h
                     self.ui.write(h)
 
         # write changeset metadata, then patch if requested
         key = self._parts[self._tref]
         self.ui.write(self.t.render(key, props))
         self._showpatch(ctx, graphwidth)
 
         if self._parts['footer']:
             if not self.footer:
                 self.footer = self.t.render(self._parts['footer'], props)
 
 def templatespec(tmpl, mapfile):
     if pycompat.ispy3:
         assert not isinstance(tmpl, str), 'tmpl must not be a str'
     if mapfile:
         return formatter.templatespec('changeset', tmpl, mapfile)
     else:
         return formatter.templatespec('', tmpl, None)
 
 def _lookuptemplate(ui, tmpl, style):
     """Find the template matching the given template spec or style
 
     See formatter.lookuptemplate() for details.
     """
 
     # ui settings
     if not tmpl and not style: # template are stronger than style
         tmpl = ui.config('ui', 'logtemplate')
         if tmpl:
             return templatespec(templater.unquotestring(tmpl), None)
         else:
             style = util.expandpath(ui.config('ui', 'style'))
 
     if not tmpl and style:
         mapfile = style
         if not os.path.split(mapfile)[0]:
             mapname = (templater.templatepath('map-cmdline.' + mapfile)
                        or templater.templatepath(mapfile))
             if mapname:
                 mapfile = mapname
         return templatespec(None, mapfile)
 
     if not tmpl:
         return templatespec(None, None)
 
     return formatter.lookuptemplate(ui, 'changeset', tmpl)
 
 def maketemplater(ui, repo, tmpl, buffered=False):
     """Create a changesettemplater from a literal template 'tmpl'
     byte-string."""
     spec = templatespec(tmpl, None)
     return changesettemplater(ui, repo, spec, buffered=buffered)
 
 def changesetdisplayer(ui, repo, opts, differ=None, buffered=False):
     """show one changeset using template or regular display.
 
     Display format will be the first non-empty hit of:
     1. option 'template'
     2. option 'style'
     3. [ui] setting 'logtemplate'
     4. [ui] setting 'style'
     If all of these values are either the unset or the empty string,
     regular display via changesetprinter() is done.
     """
     postargs = (differ, opts, buffered)
     if opts.get('template') == 'json':
         fm = ui.formatter('log', opts)
         return changesetformatter(ui, repo, fm, *postargs)
 
     spec = _lookuptemplate(ui, opts.get('template'), opts.get('style'))
 
     if not spec.ref and not spec.tmpl and not spec.mapfile:
         return changesetprinter(ui, repo, *postargs)
 
     return changesettemplater(ui, repo, spec, *postargs)
 
 def _makematcher(repo, revs, pats, opts):
     """Build matcher and expanded patterns from log options
 
     If --follow, revs are the revisions to follow from.
 
     Returns (match, pats, slowpath) where
     - match: a matcher built from the given pats and -I/-X opts
     - pats: patterns used (globs are expanded on Windows)
     - slowpath: True if patterns aren't as simple as scanning filelogs
     """
     # pats/include/exclude are passed to match.match() directly in
     # _matchfiles() revset but walkchangerevs() builds its matcher with
     # scmutil.match(). The difference is input pats are globbed on
     # platforms without shell expansion (windows).
     wctx = repo[None]
     match, pats = scmutil.matchandpats(wctx, pats, opts)
     slowpath = match.anypats() or (not match.always() and opts.get('removed'))
     if not slowpath:
         follow = opts.get('follow') or opts.get('follow_first')
         startctxs = []
         if follow and opts.get('rev'):
             startctxs = [repo[r] for r in revs]
         for f in match.files():
             if follow and startctxs:
                 # No idea if the path was a directory at that revision, so
                 # take the slow path.
                 if any(f not in c for c in startctxs):
                     slowpath = True
                     continue
             elif follow and f not in wctx:
                 # If the file exists, it may be a directory, so let it
                 # take the slow path.
                 if os.path.exists(repo.wjoin(f)):
                     slowpath = True
                     continue
                 else:
                     raise error.Abort(_('cannot follow file not in parent '
                                         'revision: "%s"') % f)
             filelog = repo.file(f)
             if not filelog:
                 # A zero count may be a directory or deleted file, so
                 # try to find matching entries on the slow path.
                 if follow:
                     raise error.Abort(
                         _('cannot follow nonexistent file: "%s"') % f)
                 slowpath = True
 
         # We decided to fall back to the slowpath because at least one
         # of the paths was not a file. Check to see if at least one of them
         # existed in history - in that case, we'll continue down the
         # slowpath; otherwise, we can turn off the slowpath
         if slowpath:
             for path in match.files():
                 if path == '.' or path in repo.store:
                     break
             else:
                 slowpath = False
 
     return match, pats, slowpath
 
 def _fileancestors(repo, revs, match, followfirst):
     fctxs = []
     for r in revs:
         ctx = repo[r]
         fctxs.extend(ctx[f].introfilectx() for f in ctx.walk(match))
 
     # When displaying a revision with --patch --follow FILE, we have
     # to know which file of the revision must be diffed. With
     # --follow, we want the names of the ancestors of FILE in the
     # revision, stored in "fcache". "fcache" is populated as a side effect
     # of the graph traversal.
     fcache = {}
     def filematcher(ctx):
         return scmutil.matchfiles(repo, fcache.get(ctx.rev(), []))
 
     def revgen():
         for rev, cs in dagop.filectxancestors(fctxs, followfirst=followfirst):
             fcache[rev] = [c.path() for c in cs]
             yield rev
     return smartset.generatorset(revgen(), iterasc=False), filematcher
 
 def _makenofollowfilematcher(repo, pats, opts):
     '''hook for extensions to override the filematcher for non-follow cases'''
     return None
 
 _opt2logrevset = {
     'no_merges':        ('not merge()', None),
     'only_merges':      ('merge()', None),
     '_matchfiles':      (None, '_matchfiles(%ps)'),
     'date':             ('date(%s)', None),
     'branch':           ('branch(%s)', '%lr'),
     '_patslog':         ('filelog(%s)', '%lr'),
     'keyword':          ('keyword(%s)', '%lr'),
     'prune':            ('ancestors(%s)', 'not %lr'),
     'user':             ('user(%s)', '%lr'),
 }
 
 def _makerevset(repo, match, pats, slowpath, opts):
     """Return a revset string built from log options and file patterns"""
     opts = dict(opts)
     # follow or not follow?
     follow = opts.get('follow') or opts.get('follow_first')
 
     # branch and only_branch are really aliases and must be handled at
     # the same time
     opts['branch'] = opts.get('branch', []) + opts.get('only_branch', [])
     opts['branch'] = [repo.lookupbranch(b) for b in opts['branch']]
 
     if slowpath:
         # See walkchangerevs() slow path.
         #
         # pats/include/exclude cannot be represented as separate
         # revset expressions as their filtering logic applies at file
         # level. For instance "-I a -X b" matches a revision touching
         # "a" and "b" while "file(a) and not file(b)" does
         # not. Besides, filesets are evaluated against the working
         # directory.
         matchargs = ['r:', 'd:relpath']
         for p in pats:
             matchargs.append('p:' + p)
         for p in opts.get('include', []):
             matchargs.append('i:' + p)
         for p in opts.get('exclude', []):
             matchargs.append('x:' + p)
         opts['_matchfiles'] = matchargs
     elif not follow:
         opts['_patslog'] = list(pats)
 
     expr = []
     for op, val in sorted(opts.iteritems()):
         if not val:
             continue
         if op not in _opt2logrevset:
             continue
         revop, listop = _opt2logrevset[op]
         if revop and '%' not in revop:
             expr.append(revop)
         elif not listop:
             expr.append(revsetlang.formatspec(revop, val))
         else:
             if revop:
                 val = [revsetlang.formatspec(revop, v) for v in val]
             expr.append(revsetlang.formatspec(listop, val))
 
     if expr:
         expr = '(' + ' and '.join(expr) + ')'
     else:
         expr = None
     return expr
 
 def _initialrevs(repo, opts):
     """Return the initial set of revisions to be filtered or followed"""
     follow = opts.get('follow') or opts.get('follow_first')
     if opts.get('rev'):
         revs = scmutil.revrange(repo, opts['rev'])
     elif follow and repo.dirstate.p1() == nullid:
         revs = smartset.baseset()
     elif follow:
         revs = repo.revs('.')
     else:
         revs = smartset.spanset(repo)
         revs.reverse()
     return revs
 
 def getrevs(repo, pats, opts):
     """Return (revs, differ) where revs is a smartset
 
     differ is a changesetdiffer with pre-configured file matcher.
     """
     follow = opts.get('follow') or opts.get('follow_first')
     followfirst = opts.get('follow_first')
     limit = getlimit(opts)
     revs = _initialrevs(repo, opts)
     if not revs:
         return smartset.baseset(), None
     match, pats, slowpath = _makematcher(repo, revs, pats, opts)
     filematcher = None
     if follow:
         if slowpath or match.always():
             revs = dagop.revancestors(repo, revs, followfirst=followfirst)
         else:
             revs, filematcher = _fileancestors(repo, revs, match, followfirst)
         revs.reverse()
     if filematcher is None:
         filematcher = _makenofollowfilematcher(repo, pats, opts)
     if filematcher is None:
         def filematcher(ctx):
             return match
 
     expr = _makerevset(repo, match, pats, slowpath, opts)
     if opts.get('graph') and opts.get('rev'):
         # User-specified revs might be unsorted, but don't sort before
         # _makerevset because it might depend on the order of revs
         if not (revs.isdescending() or revs.istopo()):
             revs.sort(reverse=True)
     if expr:
         matcher = revset.match(None, expr)
         revs = matcher(repo, revs)
     if limit is not None:
         revs = revs.slice(0, limit)
 
     differ = changesetdiffer()
     differ._makefilematcher = filematcher
     return revs, differ
 
 def _parselinerangeopt(repo, opts):
     """Parse --line-range log option and return a list of tuples (filename,
     (fromline, toline)).
     """
     linerangebyfname = []
     for pat in opts.get('line_range', []):
         try:
             pat, linerange = pat.rsplit(',', 1)
         except ValueError:
             raise error.Abort(_('malformatted line-range pattern %s') % pat)
         try:
             fromline, toline = map(int, linerange.split(':'))
         except ValueError:
             raise error.Abort(_("invalid line range for %s") % pat)
         msg = _("line range pattern '%s' must match exactly one file") % pat
         fname = scmutil.parsefollowlinespattern(repo, None, pat, msg)
         linerangebyfname.append(
             (fname, util.processlinerange(fromline, toline)))
     return linerangebyfname
 
 def getlinerangerevs(repo, userrevs, opts):
     """Return (revs, differ).
 
     "revs" are revisions obtained by processing "line-range" log options and
     walking block ancestors of each specified file/line-range.
 
     "differ" is a changesetdiffer with pre-configured file matcher and hunks
     filter.
     """
     wctx = repo[None]
 
     # Two-levels map of "rev -> file ctx -> [line range]".
     linerangesbyrev = {}
     for fname, (fromline, toline) in _parselinerangeopt(repo, opts):
         if fname not in wctx:
             raise error.Abort(_('cannot follow file not in parent '
                                 'revision: "%s"') % fname)
         fctx = wctx.filectx(fname)
         for fctx, linerange in dagop.blockancestors(fctx, fromline, toline):
             rev = fctx.introrev()
             if rev not in userrevs:
                 continue
             linerangesbyrev.setdefault(
                 rev, {}).setdefault(
                     fctx.path(), []).append(linerange)
 
     def nofilterhunksfn(fctx, hunks):
         return hunks
 
     def hunksfilter(ctx):
         fctxlineranges = linerangesbyrev.get(ctx.rev())
         if fctxlineranges is None:
             return nofilterhunksfn
 
         def filterfn(fctx, hunks):
             lineranges = fctxlineranges.get(fctx.path())
             if lineranges is not None:
                 for hr, lines in hunks:
                     if hr is None: # binary
                         yield hr, lines
                         continue
                     if any(mdiff.hunkinrange(hr[2:], lr)
                            for lr in lineranges):
                         yield hr, lines
             else:
                 for hunk in hunks:
                     yield hunk
 
         return filterfn
 
     def filematcher(ctx):
         files = list(linerangesbyrev.get(ctx.rev(), []))
         return scmutil.matchfiles(repo, files)
 
     revs = sorted(linerangesbyrev, reverse=True)
 
     differ = changesetdiffer()
     differ._makefilematcher = filematcher
     differ._makehunksfilter = hunksfilter
     return revs, differ
 
 def _graphnodeformatter(ui, displayer):
     spec = ui.config('ui', 'graphnodetemplate')
     if not spec:
         return templatekw.getgraphnode  # fast path for "{graphnode}"
 
     spec = templater.unquotestring(spec)
     if isinstance(displayer, changesettemplater):
         # reuse cache of slow templates
         tres = displayer._tresources
     else:
         tres = formatter.templateresources(ui)
     templ = formatter.maketemplater(ui, spec, defaults=templatekw.keywords,
                                     resources=tres)
     def formatnode(repo, ctx):
         props = {'ctx': ctx, 'repo': repo}
         return templ.renderdefault(props)
     return formatnode
 
 def displaygraph(ui, repo, dag, displayer, edgefn, getrenamed=None, props=None):
     props = props or {}
     formatnode = _graphnodeformatter(ui, displayer)
     state = graphmod.asciistate()
     styles = state['styles']
 
     # only set graph styling if HGPLAIN is not set.
     if ui.plain('graph'):
         # set all edge styles to |, the default pre-3.8 behaviour
         styles.update(dict.fromkeys(styles, '|'))
     else:
         edgetypes = {
             'parent': graphmod.PARENT,
             'grandparent': graphmod.GRANDPARENT,
             'missing': graphmod.MISSINGPARENT
         }
         for name, key in edgetypes.items():
             # experimental config: experimental.graphstyle.*
             styles[key] = ui.config('experimental', 'graphstyle.%s' % name,
                                     styles[key])
             if not styles[key]:
                 styles[key] = None
 
         # experimental config: experimental.graphshorten
         state['graphshorten'] = ui.configbool('experimental', 'graphshorten')
 
     for rev, type, ctx, parents in dag:
         char = formatnode(repo, ctx)
         copies = None
         if getrenamed and ctx.rev():
             copies = []
             for fn in ctx.files():
                 rename = getrenamed(fn, ctx.rev())
                 if rename:
                     copies.append((fn, rename))
         edges = edgefn(type, char, state, rev, parents)
         firstedge = next(edges)
         width = firstedge[2]
         displayer.show(ctx, copies=copies,
                        graphwidth=width, **pycompat.strkwargs(props))
         lines = displayer.hunk.pop(rev).split('\n')
         if not lines[-1]:
             del lines[-1]
         displayer.flush(ctx)
         for type, char, width, coldata in itertools.chain([firstedge], edges):
             graphmod.ascii(ui, state, type, char, lines, coldata)
             lines = []
     displayer.close()
 
 def displaygraphrevs(ui, repo, revs, displayer, getrenamed):
     revdag = graphmod.dagwalker(repo, revs)
     displaygraph(ui, repo, revdag, displayer, graphmod.asciiedges, getrenamed)
 
 def displayrevs(ui, repo, revs, displayer, getrenamed):
     for rev in revs:
         ctx = repo[rev]
         copies = None
         if getrenamed is not None and rev:
             copies = []
             for fn in ctx.files():
                 rename = getrenamed(fn, rev)
                 if rename:
                     copies.append((fn, rename))
         displayer.show(ctx, copies=copies)
         displayer.flush(ctx)
     displayer.close()
 
 def checkunsupportedgraphflags(pats, opts):
     for op in ["newest_first"]:
         if op in opts and opts[op]:
             raise error.Abort(_("-G/--graph option is incompatible with --%s")
                              % op.replace("_", "-"))
 
 def graphrevs(repo, nodes, opts):
     limit = getlimit(opts)
     nodes.reverse()
     if limit is not None:
         nodes = nodes[:limit]
     return graphmod.nodes(repo, nodes)