Actually warn on pulling from an unrelated repository

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Actually warn on pulling from an unrelated repository

add some comments to findincoming
track the base nodes of the fetch set
report if the base set only contains nullid
add a test case

manifest hash: 3fc038a6041b0967a20503f5ec8876efc038841a
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Version: GnuPG v1.4.0 (GNU/Linux)

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ClLpn0dKZnB46dh0F8zhuuk=
=emNb
-----END PGP SIGNATURE-----

tests/test-unrelated-pull

@@ -0,0 +1,17 b''
+mkdir a
+cd a
+hg init
+echo 123 > a
+hg add a
+hg commit -t "a" -u a -d "0 0"
+
+cd ..
+mkdir b
+cd b
+hg init 
+echo 321 > b
+hg add b
+hg commit -t "b" -u b -d "0 0"
+
+hg pull ../a
+hg heads

tests/test-unrelated-pull.out

@@ -0,0 +1,19 b''
+pulling from ../a
+searching for changes
+warning: pulling from an unrelated repository!
+adding changesets
+adding manifests
+adding file revisions
+modified 1 files, added 1 changesets and 1 new revisions
+(run 'hg update' to get a working copy)
+changeset:   1:9a79c33a9db37480e40fbd2a65d62ebd2a3c441c
+tag:         tip
+user:        a
+date:        Thu Jan  1 00:00:00 1970
+summary:     a
+
+changeset:   0:01f8062b2de51c0fa6428c5db1d1b3ea780189df
+user:        b
+date:        Thu Jan  1 00:00:00 1970
+summary:     b
+

mercurial/hg.py

@@ -1,1534 +1,1544 b''
 # hg.py - repository classes for mercurial
 #
 # Copyright 2005 Matt Mackall <[e-mail]>
 #
 # This software may be used and distributed according to the terms
 # of the GNU General Public License, incorporated herein by reference.
 
 import sys, struct, os
 import util
 from revlog import *
 from demandload import *
 demandload(globals(), "re lock urllib urllib2 transaction time socket")
 demandload(globals(), "tempfile httprangereader bdiff")
 
 class filelog(revlog):
     def __init__(self, opener, path):
         revlog.__init__(self, opener,
                         os.path.join("data", path + ".i"),
                         os.path.join("data", path + ".d"))
 
     def read(self, node):
         t = self.revision(node)
         if t[:2] != '\1\n':
             return t
         s = t.find('\1\n', 2)
         return t[s+2:]
 
     def readmeta(self, node):
         t = self.revision(node)
         if t[:2] != '\1\n':
             return t
         s = t.find('\1\n', 2)
         mt = t[2:s]
         for l in mt.splitlines():
             k, v = l.split(": ", 1)
             m[k] = v
         return m
 
     def add(self, text, meta, transaction, link, p1=None, p2=None):
         if meta or text[:2] == '\1\n':
             mt = ""
             if meta:
                 mt = [ "%s: %s\n" % (k, v) for k,v in meta.items() ]
             text = "\1\n" + "".join(mt) + "\1\n" + text
         return self.addrevision(text, transaction, link, p1, p2)
 
     def annotate(self, node):
 
         def decorate(text, rev):
             return ([rev] * len(text.splitlines()), text)
 
         def pair(parent, child):
             for a1, a2, b1, b2 in bdiff.blocks(parent[1], child[1]):
                 child[0][b1:b2] = parent[0][a1:a2]
             return child
 
         # find all ancestors
         needed = {node:1}
         visit = [node]
         while visit:
             n = visit.pop(0)
             for p in self.parents(n):
                 if p not in needed:
                     needed[p] = 1
                     visit.append(p)
                 else:
                     # count how many times we'll use this
                     needed[p] += 1
 
         # sort by revision which is a topological order
         visit = [ (self.rev(n), n) for n in needed.keys() ]
         visit.sort()
         hist = {}
 
         for r,n in visit:
             curr = decorate(self.read(n), self.linkrev(n))
             for p in self.parents(n):
                 if p != nullid:
                     curr = pair(hist[p], curr)
                     # trim the history of unneeded revs
                     needed[p] -= 1
                     if not needed[p]:
                         del hist[p]
             hist[n] = curr
 
         return zip(hist[n][0], hist[n][1].splitlines(1))
 
 class manifest(revlog):
     def __init__(self, opener):
         self.mapcache = None
         self.listcache = None
         self.addlist = None
         revlog.__init__(self, opener, "00manifest.i", "00manifest.d")
 
     def read(self, node):
         if node == nullid: return {} # don't upset local cache
         if self.mapcache and self.mapcache[0] == node:
             return self.mapcache[1]
         text = self.revision(node)
         map = {}
         flag = {}
         self.listcache = (text, text.splitlines(1))
         for l in self.listcache[1]:
             (f, n) = l.split('\0')
             map[f] = bin(n[:40])
             flag[f] = (n[40:-1] == "x")
         self.mapcache = (node, map, flag)
         return map
 
     def readflags(self, node):
         if node == nullid: return {} # don't upset local cache
         if not self.mapcache or self.mapcache[0] != node:
             self.read(node)
         return self.mapcache[2]
 
     def diff(self, a, b):
         # this is sneaky, as we're not actually using a and b
         if self.listcache and self.addlist and self.listcache[0] == a:
             d = mdiff.diff(self.listcache[1], self.addlist, 1)
             if mdiff.patch(a, d) != b:
                 sys.stderr.write("*** sortdiff failed, falling back ***\n")
                 return mdiff.textdiff(a, b)
             return d
         else:
             return mdiff.textdiff(a, b)
 
     def add(self, map, flags, transaction, link, p1=None, p2=None):
         files = map.keys()
         files.sort()
 
         self.addlist = ["%s\000%s%s\n" %
                         (f, hex(map[f]), flags[f] and "x" or '')
                         for f in files]
         text = "".join(self.addlist)
 
         n = self.addrevision(text, transaction, link, p1, p2)
         self.mapcache = (n, map, flags)
         self.listcache = (text, self.addlist)
         self.addlist = None
 
         return n
 
 class changelog(revlog):
     def __init__(self, opener):
         revlog.__init__(self, opener, "00changelog.i", "00changelog.d")
 
     def extract(self, text):
         if not text:
             return (nullid, "", "0", [], "")
         last = text.index("\n\n")
         desc = text[last + 2:]
         l = text[:last].splitlines()
         manifest = bin(l[0])
         user = l[1]
         date = l[2]
         files = l[3:]
         return (manifest, user, date, files, desc)
 
     def read(self, node):
         return self.extract(self.revision(node))
 
     def add(self, manifest, list, desc, transaction, p1=None, p2=None,
                   user=None, date=None):
         user = (user or
                 os.environ.get("HGUSER") or
                 os.environ.get("EMAIL") or
                 (os.environ.get("LOGNAME",
                                os.environ.get("USERNAME", "unknown"))
                  + '@' + socket.getfqdn()))
         date = date or "%d %d" % (time.time(), time.timezone)
         list.sort()
         l = [hex(manifest), user, date] + list + ["", desc]
         text = "\n".join(l)
         return self.addrevision(text, transaction, self.count(), p1, p2)
 
 class dirstate:
     def __init__(self, opener, ui, root):
         self.opener = opener
         self.root = root
         self.dirty = 0
         self.ui = ui
         self.map = None
         self.pl = None
         self.copies = {}
 
     def __del__(self):
         if self.dirty:
             self.write()
 
     def __getitem__(self, key):
         try:
             return self.map[key]
         except TypeError:
             self.read()
             return self[key]
 
     def __contains__(self, key):
         if not self.map: self.read()
         return key in self.map
 
     def parents(self):
         if not self.pl:
             self.read()
         return self.pl
 
     def setparents(self, p1, p2 = nullid):
         self.dirty = 1
         self.pl = p1, p2
 
     def state(self, key):
         try:
             return self[key][0]
         except KeyError:
             return "?"
 
     def read(self):
         if self.map is not None: return self.map
 
         self.map = {}
         self.pl = [nullid, nullid]
         try:
             st = self.opener("dirstate").read()
             if not st: return
         except: return
 
         self.pl = [st[:20], st[20: 40]]
 
         pos = 40
         while pos < len(st):
             e = struct.unpack(">cllll", st[pos:pos+17])
             l = e[4]
             pos += 17
             f = st[pos:pos + l]
             if '\0' in f:
                 f, c = f.split('\0')
                 self.copies[f] = c
             self.map[f] = e[:4]
             pos += l
 
     def copy(self, source, dest):
         self.read()
         self.dirty = 1
         self.copies[dest] = source
 
     def copied(self, file):
         return self.copies.get(file, None)
 
     def update(self, files, state):
         ''' current states:
         n  normal
         m  needs merging
         r  marked for removal
         a  marked for addition'''
 
         if not files: return
         self.read()
         self.dirty = 1
         for f in files:
             if state == "r":
                 self.map[f] = ('r', 0, 0, 0)
             else:
                 s = os.stat(os.path.join(self.root, f))
                 self.map[f] = (state, s.st_mode, s.st_size, s.st_mtime)
 
     def forget(self, files):
         if not files: return
         self.read()
         self.dirty = 1
         for f in files:
             try:
                 del self.map[f]
             except KeyError:
                 self.ui.warn("not in dirstate: %s!\n" % f)
                 pass
 
     def clear(self):
         self.map = {}
         self.dirty = 1
 
     def write(self):
         st = self.opener("dirstate", "w")
         st.write("".join(self.pl))
         for f, e in self.map.items():
             c = self.copied(f)
             if c:
                 f = f + "\0" + c
             e = struct.pack(">cllll", e[0], e[1], e[2], e[3], len(f))
             st.write(e + f)
         self.dirty = 0
 
     def changes(self, files, ignore):
         self.read()
         dc = self.map.copy()
         lookup, changed, added, unknown = [], [], [], []
 
         # compare all files by default
         if not files: files = [self.root]
 
         # recursive generator of all files listed
         def walk(files):
             for f in util.unique(files):
                 f = os.path.join(self.root, f)
                 if os.path.isdir(f):
                     for dir, subdirs, fl in os.walk(f):
                         d = dir[len(self.root) + 1:]
                         if ".hg" in subdirs: subdirs.remove(".hg")
                         for fn in fl:
                             fn = util.pconvert(os.path.join(d, fn))
                             yield fn
                 else:
                     yield f[len(self.root) + 1:]
 
         for fn in util.unique(walk(files)):
             try: s = os.stat(os.path.join(self.root, fn))
             except: continue
 
             if fn in dc:
                 c = dc[fn]
                 del dc[fn]
 
                 if c[0] == 'm':
                     changed.append(fn)
                 elif c[0] == 'a':
                     added.append(fn)
                 elif c[0] == 'r':
                     unknown.append(fn)
                 elif c[2] != s.st_size or (c[1] ^ s.st_mode) & 0100:
                     changed.append(fn)
                 elif c[1] != s.st_mode or c[3] != s.st_mtime:
                     lookup.append(fn)
             else:
                 if not ignore(fn): unknown.append(fn)
 
         return (lookup, changed, added, dc.keys(), unknown)
 
 # used to avoid circular references so destructors work
 def opener(base):
     p = base
     def o(path, mode="r"):
         if p[:7] == "http://":
             f = os.path.join(p, urllib.quote(path))
             return httprangereader.httprangereader(f)
 
         f = os.path.join(p, path)
 
         mode += "b" # for that other OS
 
         if mode[0] != "r":
             try:
                 s = os.stat(f)
             except OSError:
                 d = os.path.dirname(f)
                 if not os.path.isdir(d):
                     os.makedirs(d)
             else:
                 if s.st_nlink > 1:
                     file(f + ".tmp", "wb").write(file(f, "rb").read())
                     util.rename(f+".tmp", f)
 
         return file(f, mode)
 
     return o
 
 class RepoError(Exception): pass
 
 class localrepository:
     def __init__(self, ui, path=None, create=0):
         self.remote = 0
         if path and path[:7] == "http://":
             self.remote = 1
             self.path = path
         else:
             if not path:
                 p = os.getcwd()
                 while not os.path.isdir(os.path.join(p, ".hg")):
                     oldp = p
                     p = os.path.dirname(p)
                     if p == oldp: raise RepoError("no repo found")
                 path = p
             self.path = os.path.join(path, ".hg")
 
             if not create and not os.path.isdir(self.path):
                 raise RepoError("repository %s not found" % self.path)
 
         self.root = path
         self.ui = ui
 
         if create:
             os.mkdir(self.path)
             os.mkdir(self.join("data"))
 
         self.opener = opener(self.path)
         self.wopener = opener(self.root)
         self.manifest = manifest(self.opener)
         self.changelog = changelog(self.opener)
         self.ignorelist = None
         self.tagscache = None
         self.nodetagscache = None
 
         if not self.remote:
             self.dirstate = dirstate(self.opener, ui, self.root)
             try:
                 self.ui.readconfig(self.opener("hgrc"))
             except IOError: pass
 
     def ignore(self, f):
         if self.ignorelist is None:
             self.ignorelist = []
             try:
                 l = file(self.wjoin(".hgignore"))
                 for pat in l:
                     if pat != "\n":
                         self.ignorelist.append(re.compile(util.pconvert(pat[:-1])))
             except IOError: pass
         for pat in self.ignorelist:
             if pat.search(f): return True
         return False
 
     def hook(self, name, **args):
         s = self.ui.config("hooks", name)
         if s:
             self.ui.note("running hook %s: %s\n" % (name, s))
             old = {}
             for k, v in args.items():
                 k = k.upper()
                 old[k] = os.environ.get(k, None)
                 os.environ[k] = v
 
             r = os.system(s)
 
             for k, v in old.items():
                 if v != None:
                     os.environ[k] = v
                 else:
                     del os.environ[k]
 
             if r:
                 self.ui.warn("abort: %s hook failed with status %d!\n" %
                              (name, r))
                 return False
         return True
 
     def tags(self):
         '''return a mapping of tag to node'''
         if not self.tagscache:
             self.tagscache = {}
             try:
                 # read each head of the tags file, ending with the tip
                 # and add each tag found to the map, with "newer" ones
                 # taking precedence
                 fl = self.file(".hgtags")
                 h = fl.heads()
                 h.reverse()
                 for r in h:
                     for l in fl.revision(r).splitlines():
                         if l:
                             n, k = l.split(" ", 1)
                             try:
                                 bin_n = bin(n)
                             except TypeError:
                                 bin_n = ''
                             self.tagscache[k.strip()] = bin_n
             except KeyError:
                 pass
             for k, n in self.ui.configitems("tags"):
                 try:
                     bin_n = bin(n)
                 except TypeError:
                     bin_n = ''
                 self.tagscache[k] = bin_n
 
             self.tagscache['tip'] = self.changelog.tip()
 
         return self.tagscache
 
     def tagslist(self):
         '''return a list of tags ordered by revision'''
         l = []
         for t, n in self.tags().items():
             try:
                 r = self.changelog.rev(n)
             except:
                 r = -2 # sort to the beginning of the list if unknown
             l.append((r,t,n))
         l.sort()
         return [(t,n) for r,t,n in l]
 
     def nodetags(self, node):
         '''return the tags associated with a node'''
         if not self.nodetagscache:
             self.nodetagscache = {}
             for t,n in self.tags().items():
                 self.nodetagscache.setdefault(n,[]).append(t)
         return self.nodetagscache.get(node, [])
 
     def lookup(self, key):
         try:
             return self.tags()[key]
         except KeyError:
             return self.changelog.lookup(key)
 
     def join(self, f):
         return os.path.join(self.path, f)
 
     def wjoin(self, f):
         return os.path.join(self.root, f)
 
     def file(self, f):
         if f[0] == '/': f = f[1:]
         return filelog(self.opener, f)
 
     def wfile(self, f, mode='r'):
         return self.wopener(f, mode)
 
     def transaction(self):
         # save dirstate for undo
         try:
             ds = self.opener("dirstate").read()
         except IOError:
             ds = ""
         self.opener("undo.dirstate", "w").write(ds)
 
         return transaction.transaction(self.opener, self.join("journal"),
                                        self.join("undo"))
 
     def recover(self):
         lock = self.lock()
         if os.path.exists(self.join("journal")):
             self.ui.status("rolling back interrupted transaction\n")
             return transaction.rollback(self.opener, self.join("journal"))
         else:
             self.ui.warn("no interrupted transaction available\n")
 
     def undo(self):
         lock = self.lock()
         if os.path.exists(self.join("undo")):
             self.ui.status("rolling back last transaction\n")
             transaction.rollback(self.opener, self.join("undo"))
             self.dirstate = None
             util.rename(self.join("undo.dirstate"), self.join("dirstate"))
             self.dirstate = dirstate(self.opener, self.ui, self.root)
         else:
             self.ui.warn("no undo information available\n")
 
     def lock(self, wait = 1):
         try:
             return lock.lock(self.join("lock"), 0)
         except lock.LockHeld, inst:
             if wait:
                 self.ui.warn("waiting for lock held by %s\n" % inst.args[0])
                 return lock.lock(self.join("lock"), wait)
             raise inst
 
     def rawcommit(self, files, text, user, date, p1=None, p2=None):
         orig_parent = self.dirstate.parents()[0] or nullid
         p1 = p1 or self.dirstate.parents()[0] or nullid
         p2 = p2 or self.dirstate.parents()[1] or nullid
         c1 = self.changelog.read(p1)
         c2 = self.changelog.read(p2)
         m1 = self.manifest.read(c1[0])
         mf1 = self.manifest.readflags(c1[0])
         m2 = self.manifest.read(c2[0])
 
         if orig_parent == p1:
             update_dirstate = 1
         else:
             update_dirstate = 0
 
         tr = self.transaction()
         mm = m1.copy()
         mfm = mf1.copy()
         linkrev = self.changelog.count()
         for f in files:
             try:
                 t = self.wfile(f).read()
                 tm = util.is_exec(self.wjoin(f), mfm.get(f, False))
                 r = self.file(f)
                 mfm[f] = tm
                 mm[f] = r.add(t, {}, tr, linkrev,
                               m1.get(f, nullid), m2.get(f, nullid))
                 if update_dirstate:
                     self.dirstate.update([f], "n")
             except IOError:
                 try:
                     del mm[f]
                     del mfm[f]
                     if update_dirstate:
                         self.dirstate.forget([f])
                 except:
                     # deleted from p2?
                     pass
 
         mnode = self.manifest.add(mm, mfm, tr, linkrev, c1[0], c2[0])
         n = self.changelog.add(mnode, files, text, tr, p1, p2, user, date)
         tr.close()
         if update_dirstate:
             self.dirstate.setparents(n, nullid)
 
     def commit(self, files = None, text = "", user = None, date = None):
         commit = []
         remove = []
         if files:
             for f in files:
                 s = self.dirstate.state(f)
                 if s in 'nmai':
                     commit.append(f)
                 elif s == 'r':
                     remove.append(f)
                 else:
                     self.ui.warn("%s not tracked!\n" % f)
         else:
             (c, a, d, u) = self.changes(None, None)
             commit = c + a
             remove = d
 
         if not commit and not remove:
             self.ui.status("nothing changed\n")
             return
 
         if not self.hook("precommit"):
             return 1
 
         p1, p2 = self.dirstate.parents()
         c1 = self.changelog.read(p1)
         c2 = self.changelog.read(p2)
         m1 = self.manifest.read(c1[0])
         mf1 = self.manifest.readflags(c1[0])
         m2 = self.manifest.read(c2[0])
         lock = self.lock()
         tr = self.transaction()
 
         # check in files
         new = {}
         linkrev = self.changelog.count()
         commit.sort()
         for f in commit:
             self.ui.note(f + "\n")
             try:
                 mf1[f] = util.is_exec(self.wjoin(f), mf1.get(f, False))
                 t = self.wfile(f).read()
             except IOError:
                 self.warn("trouble committing %s!\n" % f)
                 raise
 
             meta = {}
             cp = self.dirstate.copied(f)
             if cp:
                 meta["copy"] = cp
                 meta["copyrev"] = hex(m1.get(cp, m2.get(cp, nullid)))
                 self.ui.debug(" %s: copy %s:%s\n" % (f, cp, meta["copyrev"]))
 
             r = self.file(f)
             fp1 = m1.get(f, nullid)
             fp2 = m2.get(f, nullid)
             new[f] = r.add(t, meta, tr, linkrev, fp1, fp2)
 
         # update manifest
         m1.update(new)
         for f in remove:
             if f in m1:
                 del m1[f]
         mn = self.manifest.add(m1, mf1, tr, linkrev, c1[0], c2[0])
 
         # add changeset
         new = new.keys()
         new.sort()
 
         if not text:
             edittext = "\n" + "HG: manifest hash %s\n" % hex(mn)
             edittext += "".join(["HG: changed %s\n" % f for f in new])
             edittext += "".join(["HG: removed %s\n" % f for f in remove])
             edittext = self.ui.edit(edittext)
             if not edittext.rstrip():
                 return 1
             text = edittext
 
         n = self.changelog.add(mn, new, text, tr, p1, p2, user, date)
 
         if not self.hook("commit", node=hex(n)):
             return 1
 
         tr.close()
 
         self.dirstate.setparents(n)
         self.dirstate.update(new, "n")
         self.dirstate.forget(remove)
 
     def changes(self, node1, node2, files=None):
         mf2, u = None, []
 
         def fcmp(fn, mf):
             t1 = self.wfile(fn).read()
             t2 = self.file(fn).revision(mf[fn])
             return cmp(t1, t2)
 
         # are we comparing the working directory?
         if not node2:
             l, c, a, d, u = self.dirstate.changes(files, self.ignore)
 
             # are we comparing working dir against its parent?
             if not node1:
                 if l:
                     # do a full compare of any files that might have changed
                     change = self.changelog.read(self.dirstate.parents()[0])
                     mf2 = self.manifest.read(change[0])
                     for f in l:
                         if fcmp(f, mf2):
                             c.append(f)
 
                 for l in c, a, d, u:
                     l.sort()
 
                 return (c, a, d, u)
 
         # are we comparing working dir against non-tip?
         # generate a pseudo-manifest for the working dir
         if not node2:
             if not mf2:
                 change = self.changelog.read(self.dirstate.parents()[0])
                 mf2 = self.manifest.read(change[0]).copy()
             for f in a + c + l:
                 mf2[f] = ""
             for f in d:
                 if f in mf2: del mf2[f]
         else:
             change = self.changelog.read(node2)
             mf2 = self.manifest.read(change[0])
 
         # flush lists from dirstate before comparing manifests
         c, a = [], []
 
         change = self.changelog.read(node1)
         mf1 = self.manifest.read(change[0]).copy()
 
         for fn in mf2:
             if mf1.has_key(fn):
                 if mf1[fn] != mf2[fn]:
                     if mf2[fn] != "" or fcmp(fn, mf1):
                         c.append(fn)
                 del mf1[fn]
             else:
                 a.append(fn)
 
         d = mf1.keys()
 
         for l in c, a, d, u:
             l.sort()
 
         return (c, a, d, u)
 
     def add(self, list):
         for f in list:
             p = self.wjoin(f)
             if not os.path.isfile(p):
                 self.ui.warn("%s does not exist!\n" % f)
             elif self.dirstate.state(f) == 'n':
                 self.ui.warn("%s already tracked!\n" % f)
             else:
                 self.dirstate.update([f], "a")
 
     def forget(self, list):
         for f in list:
             if self.dirstate.state(f) not in 'ai':
                 self.ui.warn("%s not added!\n" % f)
             else:
                 self.dirstate.forget([f])
 
     def remove(self, list):
         for f in list:
             p = self.wjoin(f)
             if os.path.isfile(p):
                 self.ui.warn("%s still exists!\n" % f)
             elif self.dirstate.state(f) == 'a':
                 self.ui.warn("%s never committed!\n" % f)
                 self.dirstate.forget(f)
             elif f not in self.dirstate:
                 self.ui.warn("%s not tracked!\n" % f)
             else:
                 self.dirstate.update([f], "r")
 
     def copy(self, source, dest):
         p = self.wjoin(dest)
         if not os.path.isfile(dest):
             self.ui.warn("%s does not exist!\n" % dest)
         else:
             if self.dirstate.state(dest) == '?':
                 self.dirstate.update([dest], "a")
             self.dirstate.copy(source, dest)
 
     def heads(self):
         return self.changelog.heads()
 
     def branches(self, nodes):
         if not nodes: nodes = [self.changelog.tip()]
         b = []
         for n in nodes:
             t = n
             while n:
                 p = self.changelog.parents(n)
                 if p[1] != nullid or p[0] == nullid:
                     b.append((t, n, p[0], p[1]))
                     break
                 n = p[0]
         return b
 
     def between(self, pairs):
         r = []
 
         for top, bottom in pairs:
             n, l, i = top, [], 0
             f = 1
 
             while n != bottom:
                 p = self.changelog.parents(n)[0]
                 if i == f:
                     l.append(n)
                     f = f * 2
                 n = p
                 i += 1
 
             r.append(l)
 
         return r
 
     def newer(self, nodes):
         m = {}
         nl = []
         pm = {}
         cl = self.changelog
         t = l = cl.count()
 
         # find the lowest numbered node
         for n in nodes:
             l = min(l, cl.rev(n))
             m[n] = 1
 
         for i in xrange(l, t):
             n = cl.node(i)
             if n in m: # explicitly listed
                 pm[n] = 1
                 nl.append(n)
                 continue
             for p in cl.parents(n):
                 if p in pm: # parent listed
                     pm[n] = 1
                     nl.append(n)
                     break
 
         return nl
 
     def findincoming(self, remote):
         m = self.changelog.nodemap
         search = []
         fetch = []
+        base = {}
         seen = {}
         seenbranch = {}
 
         # if we have an empty repo, fetch everything
         if self.changelog.tip() == nullid:
             self.ui.status("requesting all changes\n")
             return [nullid]
 
         # otherwise, assume we're closer to the tip than the root
+        # and start by examining the heads
         self.ui.status("searching for changes\n")
         heads = remote.heads()
         unknown = []
         for h in heads:
             if h not in m:
                 unknown.append(h)
 
         if not unknown:
             return None
 
         rep = {}
         reqcnt = 0
 
+        # search through remote branches
+        # a 'branch' here is a linear segment of history, with four parts:
+        # head, root, first parent, second parent
+        # (a branch always has two parents (or none) by definition)
         unknown = remote.branches(unknown)
         while unknown:
             r = []
             while unknown:
                 n = unknown.pop(0)
                 if n[0] in seen:
                     continue
 
                 self.ui.debug("examining %s:%s\n" % (short(n[0]), short(n[1])))
                 if n[0] == nullid:
                     break
                 if n in seenbranch:
                     self.ui.debug("branch already found\n")
                     continue
                 if n[1] and n[1] in m: # do we know the base?
                     self.ui.debug("found incomplete branch %s:%s\n"
                                   % (short(n[0]), short(n[1])))
                     search.append(n) # schedule branch range for scanning
                     seenbranch[n] = 1
                 else:
                     if n[1] not in seen and n[1] not in fetch:
                         if n[2] in m and n[3] in m:
                             self.ui.debug("found new changeset %s\n" %
                                           short(n[1]))
                             fetch.append(n[1]) # earliest unknown
+                            base[n[2]] = 1 # latest known
                             continue
 
                     for a in n[2:4]:
                         if a not in rep:
                             r.append(a)
                             rep[a] = 1
 
                 seen[n[0]] = 1
 
             if r:
                 reqcnt += 1
                 self.ui.debug("request %d: %s\n" %
                             (reqcnt, " ".join(map(short, r))))
                 for p in range(0, len(r), 10):
                     for b in remote.branches(r[p:p+10]):
                         self.ui.debug("received %s:%s\n" %
                                       (short(b[0]), short(b[1])))
                         if b[0] not in m and b[0] not in seen:
                             unknown.append(b)
 
+        # do binary search on the branches we found
         while search:
             n = search.pop(0)
             reqcnt += 1
             l = remote.between([(n[0], n[1])])[0]
             l.append(n[1])
             p = n[0]
             f = 1
             for i in l:
                 self.ui.debug("narrowing %d:%d %s\n" % (f, len(l), short(i)))
                 if i in m:
                     if f <= 2:
                         self.ui.debug("found new branch changeset %s\n" %
                                           short(p))
                         fetch.append(p)
+                        base[i] = 1
                     else:
                         self.ui.debug("narrowed branch search to %s:%s\n"
                                       % (short(p), short(i)))
                         search.append((p, i))
                     break
                 p, f = i, f * 2
 
+        # sanity check our fetch list
         for f in fetch:
             if f in m:
                 raise RepoError("already have changeset " + short(f[:4]))
 
-        if fetch == [nullid]:
+        if base.keys() == [nullid]:
             self.ui.warn("warning: pulling from an unrelated repository!\n")
 
         self.ui.note("adding new changesets starting at " +
                      " ".join([short(f) for f in fetch]) + "\n")
 
         self.ui.debug("%d total queries\n" % reqcnt)
 
         return fetch
 
     def changegroup(self, basenodes):
         nodes = self.newer(basenodes)
 
         # construct the link map
         linkmap = {}
         for n in nodes:
             linkmap[self.changelog.rev(n)] = n
 
         # construct a list of all changed files
         changed = {}
         for n in nodes:
             c = self.changelog.read(n)
             for f in c[3]:
                 changed[f] = 1
         changed = changed.keys()
         changed.sort()
 
         # the changegroup is changesets + manifests + all file revs
         revs = [ self.changelog.rev(n) for n in nodes ]
 
         for y in self.changelog.group(linkmap): yield y
         for y in self.manifest.group(linkmap): yield y
         for f in changed:
             yield struct.pack(">l", len(f) + 4) + f
             g = self.file(f).group(linkmap)
             for y in g:
                 yield y
 
     def addchangegroup(self, generator):
 
         class genread:
             def __init__(self, generator):
                 self.g = generator
                 self.buf = ""
             def read(self, l):
                 while l > len(self.buf):
                     try:
                         self.buf += self.g.next()
                     except StopIteration:
                         break
                 d, self.buf = self.buf[:l], self.buf[l:]
                 return d
 
         def getchunk():
             d = source.read(4)
             if not d: return ""
             l = struct.unpack(">l", d)[0]
             if l <= 4: return ""
             return source.read(l - 4)
 
         def getgroup():
             while 1:
                 c = getchunk()
                 if not c: break
                 yield c
 
         def csmap(x):
             self.ui.debug("add changeset %s\n" % short(x))
             return self.changelog.count()
 
         def revmap(x):
             return self.changelog.rev(x)
 
         if not generator: return
         changesets = files = revisions = 0
 
         source = genread(generator)
         lock = self.lock()
         tr = self.transaction()
 
         # pull off the changeset group
         self.ui.status("adding changesets\n")
         co = self.changelog.tip()
         cn = self.changelog.addgroup(getgroup(), csmap, tr, 1) # unique
         changesets = self.changelog.rev(cn) - self.changelog.rev(co)
 
         # pull off the manifest group
         self.ui.status("adding manifests\n")
         mm = self.manifest.tip()
         mo = self.manifest.addgroup(getgroup(), revmap, tr)
 
         # process the files
         self.ui.status("adding file revisions\n")
         while 1:
             f = getchunk()
             if not f: break
             self.ui.debug("adding %s revisions\n" % f)
             fl = self.file(f)
             o = fl.count()
             n = fl.addgroup(getgroup(), revmap, tr)
             revisions += fl.count() - o
             files += 1
 
         self.ui.status(("modified %d files, added %d changesets" +
                         " and %d new revisions\n")
                        % (files, changesets, revisions))
 
         tr.close()
         return
 
     def update(self, node, allow=False, force=False):
         pl = self.dirstate.parents()
         if not force and pl[1] != nullid:
             self.ui.warn("aborting: outstanding uncommitted merges\n")
             return
 
         p1, p2 = pl[0], node
         pa = self.changelog.ancestor(p1, p2)
         m1n = self.changelog.read(p1)[0]
         m2n = self.changelog.read(p2)[0]
         man = self.manifest.ancestor(m1n, m2n)
         m1 = self.manifest.read(m1n)
         mf1 = self.manifest.readflags(m1n)
         m2 = self.manifest.read(m2n)
         mf2 = self.manifest.readflags(m2n)
         ma = self.manifest.read(man)
         mfa = self.manifest.readflags(man)
 
         (c, a, d, u) = self.changes(None, None)
 
         # is this a jump, or a merge?  i.e. is there a linear path
         # from p1 to p2?
         linear_path = (pa == p1 or pa == p2)
 
         # resolve the manifest to determine which files
         # we care about merging
         self.ui.note("resolving manifests\n")
         self.ui.debug(" ancestor %s local %s remote %s\n" %
                       (short(man), short(m1n), short(m2n)))
 
         merge = {}
         get = {}
         remove = []
         mark = {}
 
         # construct a working dir manifest
         mw = m1.copy()
         mfw = mf1.copy()
         umap = dict.fromkeys(u)
 
         for f in a + c + u:
             mw[f] = ""
             mfw[f] = util.is_exec(self.wjoin(f), mfw.get(f, False))
 
         for f in d:
             if f in mw: del mw[f]
 
             # If we're jumping between revisions (as opposed to merging),
             # and if neither the working directory nor the target rev has
             # the file, then we need to remove it from the dirstate, to
             # prevent the dirstate from listing the file when it is no
             # longer in the manifest.
             if linear_path and f not in m2:
                 self.dirstate.forget((f,))
 
         # Compare manifests
         for f, n in mw.iteritems():
             if f in m2:
                 s = 0
 
                 # is the wfile new since m1, and match m2?
                 if f not in m1:
                     t1 = self.wfile(f).read()
                     t2 = self.file(f).revision(m2[f])
                     if cmp(t1, t2) == 0:
                         mark[f] = 1
                         n = m2[f]
                     del t1, t2
 
                 # are files different?
                 if n != m2[f]:
                     a = ma.get(f, nullid)
                     # are both different from the ancestor?
                     if n != a and m2[f] != a:
                         self.ui.debug(" %s versions differ, resolve\n" % f)
                         # merge executable bits
                         # "if we changed or they changed, change in merge"
                         a, b, c = mfa.get(f, 0), mfw[f], mf2[f]
                         mode = ((a^b) | (a^c)) ^ a
                         merge[f] = (m1.get(f, nullid), m2[f], mode)
                         s = 1
                     # are we clobbering?
                     # is remote's version newer?
                     # or are we going back in time?
                     elif force or m2[f] != a or (p2 == pa and mw[f] == m1[f]):
                         self.ui.debug(" remote %s is newer, get\n" % f)
                         get[f] = m2[f]
                         s = 1
                     else:
                         mark[f] = 1
                 elif f in umap:
                     # this unknown file is the same as the checkout
                     get[f] = m2[f]
 
                 if not s and mfw[f] != mf2[f]:
                     if force:
                         self.ui.debug(" updating permissions for %s\n" % f)
                         util.set_exec(self.wjoin(f), mf2[f])
                     else:
                         a, b, c = mfa.get(f, 0), mfw[f], mf2[f]
                         mode = ((a^b) | (a^c)) ^ a
                         if mode != b:
                             self.ui.debug(" updating permissions for %s\n" % f)
                             util.set_exec(self.wjoin(f), mode)
                             mark[f] = 1
                 del m2[f]
             elif f in ma:
                 if not force and n != ma[f]:
                     r = ""
                     if linear_path or allow:
                         r = self.ui.prompt(
                             (" local changed %s which remote deleted\n" % f) +
                             "(k)eep or (d)elete?", "[kd]", "k")
                     if r == "d":
                         remove.append(f)
                 else:
                     self.ui.debug("other deleted %s\n" % f)
                     remove.append(f) # other deleted it
             else:
                 if n == m1.get(f, nullid): # same as parent
                     if p2 == pa: # going backwards?
                         self.ui.debug("remote deleted %s\n" % f)
                         remove.append(f)
                     else:
                         self.ui.debug("local created %s, keeping\n" % f)
                 else:
                     self.ui.debug("working dir created %s, keeping\n" % f)
 
         for f, n in m2.iteritems():
             if f[0] == "/": continue
             if not force and f in ma and n != ma[f]:
                 r = ""
                 if linear_path or allow:
                     r = self.ui.prompt(
                         ("remote changed %s which local deleted\n" % f) +
                         "(k)eep or (d)elete?", "[kd]", "k")
                 if r == "d": remove.append(f)
             else:
                 self.ui.debug("remote created %s\n" % f)
                 get[f] = n
 
         del mw, m1, m2, ma
 
         if force:
             for f in merge:
                 get[f] = merge[f][1]
             merge = {}
 
         if linear_path:
             # we don't need to do any magic, just jump to the new rev
             mode = 'n'
             p1, p2 = p2, nullid
         else:
             if not allow:
                 self.ui.status("this update spans a branch" +
                                " affecting the following files:\n")
                 fl = merge.keys() + get.keys()
                 fl.sort()
                 for f in fl:
                     cf = ""
                     if f in merge: cf = " (resolve)"
                     self.ui.status(" %s%s\n" % (f, cf))
                 self.ui.warn("aborting update spanning branches!\n")
                 self.ui.status("(use update -m to perform a branch merge)\n")
                 return 1
             # we have to remember what files we needed to get/change
             # because any file that's different from either one of its
             # parents must be in the changeset
             mode = 'm'
             self.dirstate.update(mark.keys(), "m")
 
         self.dirstate.setparents(p1, p2)
 
         # get the files we don't need to change
         files = get.keys()
         files.sort()
         for f in files:
             if f[0] == "/": continue
             self.ui.note("getting %s\n" % f)
             t = self.file(f).read(get[f])
             try:
                 self.wfile(f, "w").write(t)
             except IOError:
                 os.makedirs(os.path.dirname(self.wjoin(f)))
                 self.wfile(f, "w").write(t)
             util.set_exec(self.wjoin(f), mf2[f])
             self.dirstate.update([f], mode)
 
         # merge the tricky bits
         files = merge.keys()
         files.sort()
         for f in files:
             self.ui.status("merging %s\n" % f)
             m, o, flag = merge[f]
             self.merge3(f, m, o)
             util.set_exec(self.wjoin(f), flag)
             self.dirstate.update([f], 'm')
 
         for f in remove:
             self.ui.note("removing %s\n" % f)
             os.unlink(f)
             # try removing directories that might now be empty
             try: os.removedirs(os.path.dirname(f))
             except: pass
         if mode == 'n':
             self.dirstate.forget(remove)
         else:
             self.dirstate.update(remove, 'r')
 
     def merge3(self, fn, my, other):
         """perform a 3-way merge in the working directory"""
 
         def temp(prefix, node):
             pre = "%s~%s." % (os.path.basename(fn), prefix)
             (fd, name) = tempfile.mkstemp("", pre)
             f = os.fdopen(fd, "wb")
             f.write(fl.revision(node))
             f.close()
             return name
 
         fl = self.file(fn)
         base = fl.ancestor(my, other)
         a = self.wjoin(fn)
         b = temp("base", base)
         c = temp("other", other)
 
         self.ui.note("resolving %s\n" % fn)
         self.ui.debug("file %s: other %s ancestor %s\n" %
                               (fn, short(other), short(base)))
 
         cmd = os.environ.get("HGMERGE", "hgmerge")
         r = os.system("%s %s %s %s" % (cmd, a, b, c))
         if r:
             self.ui.warn("merging %s failed!\n" % fn)
 
         os.unlink(b)
         os.unlink(c)
 
     def verify(self):
         filelinkrevs = {}
         filenodes = {}
         changesets = revisions = files = 0
         errors = 0
 
         seen = {}
         self.ui.status("checking changesets\n")
         for i in range(self.changelog.count()):
             changesets += 1
             n = self.changelog.node(i)
             if n in seen:
                 self.ui.warn("duplicate changeset at revision %d\n" % i)
                 errors += 1
             seen[n] = 1
 
             for p in self.changelog.parents(n):
                 if p not in self.changelog.nodemap:
                     self.ui.warn("changeset %s has unknown parent %s\n" %
                                  (short(n), short(p)))
                     errors += 1
             try:
                 changes = self.changelog.read(n)
             except Exception, inst:
                 self.ui.warn("unpacking changeset %s: %s\n" % (short(n), inst))
                 errors += 1
 
             for f in changes[3]:
                 filelinkrevs.setdefault(f, []).append(i)
 
         seen = {}
         self.ui.status("checking manifests\n")
         for i in range(self.manifest.count()):
             n = self.manifest.node(i)
             if n in seen:
                 self.ui.warn("duplicate manifest at revision %d\n" % i)
                 errors += 1
             seen[n] = 1
 
             for p in self.manifest.parents(n):
                 if p not in self.manifest.nodemap:
                     self.ui.warn("manifest %s has unknown parent %s\n" %
                             (short(n), short(p)))
                     errors += 1
 
             try:
                 delta = mdiff.patchtext(self.manifest.delta(n))
             except KeyboardInterrupt:
                 print "aborted"
                 sys.exit(0)
             except Exception, inst:
                 self.ui.warn("unpacking manifest %s: %s\n"
                              % (short(n), inst))
                 errors += 1
 
             ff = [ l.split('\0') for l in delta.splitlines() ]
             for f, fn in ff:
                 filenodes.setdefault(f, {})[bin(fn[:40])] = 1
 
         self.ui.status("crosschecking files in changesets and manifests\n")
         for f in filenodes:
             if f not in filelinkrevs:
                 self.ui.warn("file %s in manifest but not in changesets\n" % f)
                 errors += 1
 
         for f in filelinkrevs:
             if f not in filenodes:
                 self.ui.warn("file %s in changeset but not in manifest\n" % f)
                 errors += 1
 
         self.ui.status("checking files\n")
         ff = filenodes.keys()
         ff.sort()
         for f in ff:
             if f == "/dev/null": continue
             files += 1
             fl = self.file(f)
             nodes = { nullid: 1 }
             seen = {}
             for i in range(fl.count()):
                 revisions += 1
                 n = fl.node(i)
 
                 if n in seen:
                     self.ui.warn("%s: duplicate revision %d\n" % (f, i))
                     errors += 1
 
                 if n not in filenodes[f]:
                     self.ui.warn("%s: %d:%s not in manifests\n"
                                  % (f, i, short(n)))
                     print len(filenodes[f].keys()), fl.count(), f
                     errors += 1
                 else:
                     del filenodes[f][n]
 
                 flr = fl.linkrev(n)
                 if flr not in filelinkrevs[f]:
                     self.ui.warn("%s:%s points to unexpected changeset %d\n"
                             % (f, short(n), fl.linkrev(n)))
                     errors += 1
                 else:
                     filelinkrevs[f].remove(flr)
 
                 # verify contents
                 try:
                     t = fl.read(n)
                 except Exception, inst:
                     self.ui.warn("unpacking file %s %s: %s\n"
                                  % (f, short(n), inst))
                     errors += 1
 
                 # verify parents
                 (p1, p2) = fl.parents(n)
                 if p1 not in nodes:
                     self.ui.warn("file %s:%s unknown parent 1 %s" %
                             (f, short(n), short(p1)))
                     errors += 1
                 if p2 not in nodes:
                     self.ui.warn("file %s:%s unknown parent 2 %s" %
                             (f, short(n), short(p1)))
                     errors += 1
                 nodes[n] = 1
 
             # cross-check
             for node in filenodes[f]:
                 self.ui.warn("node %s in manifests not in %s\n"
                              % (hex(n), f))
                 errors += 1
 
         self.ui.status("%d files, %d changesets, %d total revisions\n" %
                        (files, changesets, revisions))
 
         if errors:
             self.ui.warn("%d integrity errors encountered!\n" % errors)
             return 1
 
 class remoterepository:
     def __init__(self, ui, path):
         self.url = path
         self.ui = ui
         no_list = [ "localhost", "127.0.0.1" ]
         host = ui.config("http_proxy", "host")
         if host is None:
             host = os.environ.get("http_proxy")
         if host and host.startswith('http://'):
             host = host[7:]
         user = ui.config("http_proxy", "user")
         passwd = ui.config("http_proxy", "passwd")
         no = ui.config("http_proxy", "no")
         if no is None:
             no = os.environ.get("no_proxy")
         if no:
             no_list = no_list + no.split(",")
 
         no_proxy = 0
         for h in no_list:
             if (path.startswith("http://" + h + "/") or
                 path.startswith("http://" + h + ":") or
                 path == "http://" + h):
                 no_proxy = 1
 
         # Note: urllib2 takes proxy values from the environment and those will
         # take precedence
         for env in ["HTTP_PROXY", "http_proxy", "no_proxy"]:
             if os.environ.has_key(env):
                 del os.environ[env]
 
         proxy_handler = urllib2.BaseHandler()
         if host and not no_proxy:
             proxy_handler = urllib2.ProxyHandler({"http" : "http://" + host})
 
         authinfo = None
         if user and passwd:
             passmgr = urllib2.HTTPPasswordMgrWithDefaultRealm()
             passmgr.add_password(None, host, user, passwd)
             authinfo = urllib2.ProxyBasicAuthHandler(passmgr)
 
         opener = urllib2.build_opener(proxy_handler, authinfo)
         urllib2.install_opener(opener)
 
     def do_cmd(self, cmd, **args):
         self.ui.debug("sending %s command\n" % cmd)
         q = {"cmd": cmd}
         q.update(args)
         qs = urllib.urlencode(q)
         cu = "%s?%s" % (self.url, qs)
         return urllib2.urlopen(cu)
 
     def heads(self):
         d = self.do_cmd("heads").read()
         try:
             return map(bin, d[:-1].split(" "))
         except:
             self.ui.warn("unexpected response:\n" + d[:400] + "\n...\n")
             raise
 
     def branches(self, nodes):
         n = " ".join(map(hex, nodes))
         d = self.do_cmd("branches", nodes=n).read()
         try:
             br = [ tuple(map(bin, b.split(" "))) for b in d.splitlines() ]
             return br
         except:
             self.ui.warn("unexpected response:\n" + d[:400] + "\n...\n")
             raise
 
     def between(self, pairs):
         n = "\n".join(["-".join(map(hex, p)) for p in pairs])
         d = self.do_cmd("between", pairs=n).read()
         try:
             p = [ l and map(bin, l.split(" ")) or [] for l in d.splitlines() ]
             return p
         except:
             self.ui.warn("unexpected response:\n" + d[:400] + "\n...\n")
             raise
 
     def changegroup(self, nodes):
         n = " ".join(map(hex, nodes))
         zd = zlib.decompressobj()
         f = self.do_cmd("changegroup", roots=n)
         bytes = 0
         while 1:
             d = f.read(4096)
             bytes += len(d)
             if not d:
                 yield zd.flush()
                 break
             yield zd.decompress(d)
         self.ui.note("%d bytes of data transfered\n" % bytes)
 
 def repository(ui, path=None, create=0):
     if path and path[:7] == "http://":
         return remoterepository(ui, path)
     if path and path[:5] == "hg://":
         return remoterepository(ui, path.replace("hg://", "http://"))
     if path and path[:11] == "old-http://":
         return localrepository(ui, path.replace("old-http://", "http://"))
     else:
         return localrepository(ui, path, create)