rev-branch-cache: stop pretending we will overwrite data when we don't

We were issuing a message about overwriting data even when we were about to
write 0 bytes in pratice. This is silly. Instead we point at the extra data
remaining in the file (in case someone is using debug to debug something).

mercurial/branching/rev_cache.py

@@ -1,427 +1,434
 # rev_cache.py - caching branch information per revision
 #
 # 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 annotations
 
 import os
 import struct
 
 from ..node import (
     nullrev,
 )
 
 from .. import (
     encoding,
     error,
     util,
 )
 
 from ..utils import (
     stringutil,
 )
 
 calcsize = struct.calcsize
 pack_into = struct.pack_into
 unpack_from = struct.unpack_from
 
 
 # Revision branch info cache
 
 # The "V2" version use the same format as the "V1" but garantee it won't be
 # truncated, preventing SIGBUS when it is mmap-ed
 _rbcversion = b'-v2'
 _rbcnames = b'rbc-names' + _rbcversion
 _rbcrevs = b'rbc-revs' + _rbcversion
 _rbc_legacy_version = b'-v1'
 _rbc_legacy_names = b'rbc-names' + _rbc_legacy_version
 _rbc_legacy_revs = b'rbc-revs' + _rbc_legacy_version
 # [4 byte hash prefix][4 byte branch name number with sign bit indicating open]
 _rbcrecfmt = b'>4sI'
 _rbcrecsize = calcsize(_rbcrecfmt)
 _rbcmininc = 64 * _rbcrecsize
 _rbcnodelen = 4
 _rbcbranchidxmask = 0x7FFFFFFF
 _rbccloseflag = 0x80000000
 
 
 # with atomic replacement.
 REWRITE_RATIO = 0.2
 
 
 class rbcrevs:
     """a byte string consisting of an immutable prefix followed by a mutable suffix"""
 
     def __init__(self, revs):
         self._prefix = revs
         self._rest = bytearray()
 
     def __len__(self):
         return len(self._prefix) + len(self._rest)
 
     def unpack_record(self, rbcrevidx):
         if rbcrevidx < len(self._prefix):
             return unpack_from(_rbcrecfmt, util.buffer(self._prefix), rbcrevidx)
         else:
             return unpack_from(
                 _rbcrecfmt,
                 util.buffer(self._rest),
                 rbcrevidx - len(self._prefix),
             )
 
     def make_mutable(self):
         if len(self._prefix) > 0:
             entirety = bytearray()
             entirety[:] = self._prefix
             entirety.extend(self._rest)
             self._rest = entirety
             self._prefix = bytearray()
 
     def truncate(self, pos):
         self.make_mutable()
         del self._rest[pos:]
 
     def pack_into(self, rbcrevidx, node, branchidx):
         if rbcrevidx < len(self._prefix):
             self.make_mutable()
         buf = self._rest
         start_offset = rbcrevidx - len(self._prefix)
         end_offset = start_offset + _rbcrecsize
 
         if len(self._rest) < end_offset:
             # bytearray doesn't allocate extra space at least in Python 3.7.
             # When multiple changesets are added in a row, precise resize would
             # result in quadratic complexity. Overallocate to compensate by
             # using the classic doubling technique for dynamic arrays instead.
             # If there was a gap in the map before, less space will be reserved.
             self._rest.extend(b'\0' * end_offset)
         return pack_into(
             _rbcrecfmt,
             buf,
             start_offset,
             node,
             branchidx,
         )
 
     def extend(self, extension):
         return self._rest.extend(extension)
 
     def slice(self, begin, end):
         if begin < len(self._prefix):
             acc = bytearray()
             acc[:] = self._prefix[begin:end]
             acc.extend(
                 self._rest[begin - len(self._prefix) : end - len(self._prefix)]
             )
             return acc
         return self._rest[begin - len(self._prefix) : end - len(self._prefix)]
 
 
 class revbranchcache:
     """Persistent cache, mapping from revision number to branch name and close.
     This is a low level cache, independent of filtering.
 
     Branch names are stored in rbc-names in internal encoding separated by 0.
     rbc-names is append-only, and each branch name is only stored once and will
     thus have a unique index.
 
     The branch info for each revision is stored in rbc-revs as constant size
     records. The whole file is read into memory, but it is only 'parsed' on
     demand. The file is usually append-only but will be truncated if repo
     modification is detected.
     The record for each revision contains the first 4 bytes of the
     corresponding node hash, and the record is only used if it still matches.
     Even a completely trashed rbc-revs fill thus still give the right result
     while converging towards full recovery ... assuming no incorrectly matching
     node hashes.
     The record also contains 4 bytes where 31 bits contains the index of the
     branch and the last bit indicate that it is a branch close commit.
     The usage pattern for rbc-revs is thus somewhat similar to 00changelog.i
     and will grow with it but be 1/8th of its size.
     """
 
     def __init__(self, repo, readonly=True):
         assert repo.filtername is None
         self._repo = repo
         self._names = []  # branch names in local encoding with static index
         self._rbcrevs = rbcrevs(bytearray())
         self._rbcsnameslen = 0  # length of names read at _rbcsnameslen
         self._force_overwrite = False
         v1_fallback = False
         try:
             try:
                 bndata = repo.cachevfs.read(_rbcnames)
             except (IOError, OSError):
                 # If we don't have "v2" data, we might have "v1" data worth
                 # using.
                 #
                 # consider stop doing this many version after hg-6.9 release
                 bndata = repo.cachevfs.read(_rbc_legacy_names)
                 v1_fallback = True
                 self._force_overwrite = True
             self._rbcsnameslen = len(bndata)  # for verification before writing
             if bndata:
                 self._names = [
                     encoding.tolocal(bn) for bn in bndata.split(b'\0')
                 ]
         except (IOError, OSError):
             if readonly:
                 # don't try to use cache - fall back to the slow path
                 self.branchinfo = self._branchinfo
 
         if self._names:
             try:
                 usemmap = repo.ui.configbool(b'storage', b'revbranchcache.mmap')
                 if not v1_fallback:
                     with repo.cachevfs(_rbcrevs) as fp:
                         if usemmap and repo.cachevfs.is_mmap_safe(_rbcrevs):
                             data = util.buffer(util.mmapread(fp))
                         else:
                             data = fp.read()
                 else:
                     # If we don't have "v2" data, we might have "v1" data worth
                     # using.
                     #
                     # Consider stop doing this many version after hg-6.9
                     # release.
                     with repo.cachevfs(_rbc_legacy_revs) as fp:
                         data = fp.read()
                 self._rbcrevs = rbcrevs(data)
             except (IOError, OSError) as inst:
                 repo.ui.debug(
                     b"couldn't read revision branch cache: %s\n"
                     % stringutil.forcebytestr(inst)
                 )
         # remember number of good records on disk
         self._rbcrevslen = min(
             len(self._rbcrevs) // _rbcrecsize, len(repo.changelog)
         )
         if self._rbcrevslen == 0:
             self._names = []
         self._rbcnamescount = len(self._names)  # number of names read at
         # _rbcsnameslen
 
     def _clear(self):
         self._rbcsnameslen = 0
         del self._names[:]
         self._rbcnamescount = 0
         self._rbcrevslen = len(self._repo.changelog)
         self._rbcrevs = rbcrevs(bytearray(self._rbcrevslen * _rbcrecsize))
         util.clearcachedproperty(self, b'_namesreverse')
         self._force_overwrite = True
 
     def invalidate(self, rev=0):
         self._rbcrevslen = rev
         self._rbcrevs.truncate(rev)
         self._force_overwrite = True
 
     @util.propertycache
     def _namesreverse(self):
         return {b: r for r, b in enumerate(self._names)}
 
     def branchinfo(self, rev):
         """Return branch name and close flag for rev, using and updating
         persistent cache."""
         changelog = self._repo.changelog
         rbcrevidx = rev * _rbcrecsize
 
         # avoid negative index, changelog.read(nullrev) is fast without cache
         if rev == nullrev:
             return changelog.branchinfo(rev)
 
         # if requested rev isn't allocated, grow and cache the rev info
         if len(self._rbcrevs) < rbcrevidx + _rbcrecsize:
             return self._branchinfo(rev)
 
         # fast path: extract data from cache, use it if node is matching
         reponode = changelog.node(rev)[:_rbcnodelen]
         cachenode, branchidx = self._rbcrevs.unpack_record(rbcrevidx)
         close = bool(branchidx & _rbccloseflag)
         if close:
             branchidx &= _rbcbranchidxmask
         if cachenode == b'\0\0\0\0':
             pass
         elif cachenode == reponode:
             try:
                 return self._names[branchidx], close
             except IndexError:
                 # recover from invalid reference to unknown branch
                 self._repo.ui.debug(
                     b"referenced branch names not found"
                     b" - rebuilding revision branch cache from scratch\n"
                 )
                 self._clear()
         else:
             # rev/node map has changed, invalidate the cache from here up
             self._repo.ui.debug(
                 b"history modification detected - truncating "
                 b"revision branch cache to revision %d\n" % rev
             )
             truncate = rbcrevidx + _rbcrecsize
             self._rbcrevs.truncate(truncate)
             self._rbcrevslen = min(self._rbcrevslen, truncate)
 
         # fall back to slow path and make sure it will be written to disk
         return self._branchinfo(rev)
 
     def _branchinfo(self, rev):
         """Retrieve branch info from changelog and update _rbcrevs"""
         changelog = self._repo.changelog
         b, close = changelog.branchinfo(rev)
         if b in self._namesreverse:
             branchidx = self._namesreverse[b]
         else:
             branchidx = len(self._names)
             self._names.append(b)
             self._namesreverse[b] = branchidx
         reponode = changelog.node(rev)
         if close:
             branchidx |= _rbccloseflag
         self._setcachedata(rev, reponode, branchidx)
         return b, close
 
     def setdata(self, rev, changelogrevision):
         """add new data information to the cache"""
         branch, close = changelogrevision.branchinfo
 
         if branch in self._namesreverse:
             branchidx = self._namesreverse[branch]
         else:
             branchidx = len(self._names)
             self._names.append(branch)
             self._namesreverse[branch] = branchidx
         if close:
             branchidx |= _rbccloseflag
         self._setcachedata(rev, self._repo.changelog.node(rev), branchidx)
         # If no cache data were readable (non exists, bad permission, etc)
         # the cache was bypassing itself by setting:
         #
         #   self.branchinfo = self._branchinfo
         #
         # Since we now have data in the cache, we need to drop this bypassing.
         if 'branchinfo' in vars(self):
             del self.branchinfo
 
     def _setcachedata(self, rev, node, branchidx):
         """Writes the node's branch data to the in-memory cache data."""
         if rev == nullrev:
             return
         rbcrevidx = rev * _rbcrecsize
         self._rbcrevs.pack_into(rbcrevidx, node, branchidx)
         self._rbcrevslen = min(self._rbcrevslen, rev)
 
         tr = self._repo.currenttransaction()
         if tr:
             tr.addfinalize(b'write-revbranchcache', self.write)
 
     def write(self, tr=None):
         """Save branch cache if it is dirty."""
         repo = self._repo
         wlock = None
         step = b''
         try:
             # write the new names
             if self._force_overwrite or self._rbcnamescount < len(self._names):
                 wlock = repo.wlock(wait=False)
                 step = b' names'
                 self._writenames(repo)
 
             # write the new revs
             start = self._rbcrevslen * _rbcrecsize
             if self._force_overwrite or start != len(self._rbcrevs):
                 step = b''
                 if wlock is None:
                     wlock = repo.wlock(wait=False)
                 self._writerevs(repo, start)
 
         except (IOError, OSError, error.Abort, error.LockError) as inst:
             repo.ui.debug(
                 b"couldn't write revision branch cache%s: %s\n"
                 % (step, stringutil.forcebytestr(inst))
             )
         finally:
             if wlock is not None:
                 wlock.release()
 
     def _writenames(self, repo):
         """write the new branch names to revbranchcache"""
         f = None
         if self._force_overwrite:
             self._rbcsnameslen = 0
             self._rbcnamescount = 0
         try:
             if self._force_overwrite or self._rbcnamescount != 0:
                 f = repo.cachevfs.open(_rbcnames, b'ab')
                 current_size = f.tell()
                 if current_size == self._rbcsnameslen:
                     f.write(b'\0')
                 else:
                     f.close()
                     if self._force_overwrite:
                         dbg = b"resetting content of %s\n"
                     elif current_size > 0:
                         dbg = b"%s changed - rewriting it\n"
                     else:
                         dbg = b"%s is missing - rewriting it\n"
                     repo.ui.debug(dbg % _rbcnames)
                     self._rbcnamescount = 0
                     self._rbcrevslen = 0
             if self._rbcnamescount == 0:
                 # before rewriting names, make sure references are removed
                 repo.cachevfs.unlinkpath(_rbcrevs, ignoremissing=True)
                 f = repo.cachevfs.open(_rbcnames, b'wb')
             names = self._names[self._rbcnamescount :]
             from_local = encoding.fromlocal
             data = b'\0'.join(from_local(b) for b in names)
             f.write(data)
             self._rbcsnameslen = f.tell()
         finally:
             if f is not None:
                 f.close()
         self._rbcnamescount = len(self._names)
 
     def _writerevs(self, repo, start):
         """write the new revs to revbranchcache"""
         revs = min(len(repo.changelog), len(self._rbcrevs) // _rbcrecsize)
 
         end = revs * _rbcrecsize
         if self._force_overwrite:
             start = 0
 
         with repo.cachevfs.open(_rbcrevs, b'a+b') as f:
             pass  # this make sure the file exist…
         with repo.cachevfs.open(_rbcrevs, b'r+b') as f:
             f.seek(0, os.SEEK_END)
             current_size = f.tell()
             if current_size < start:
                 start = 0
             if current_size != start:
                 threshold = current_size * REWRITE_RATIO
-                if (max(end, current_size) - start) < threshold:
-                    # end affected, let overwrite the bad value
-                    overwritten = min(end, current_size) - start
+                overwritten = min(end, current_size) - start
+                if (max(end, current_size) - start) >= threshold:
+                    start = 0
+                    dbg = b"resetting content of cache/%s\n" % _rbcrevs
+                    repo.ui.debug(dbg)
+                elif overwritten > 0:
+                    # end affected, let us overwrite the bad value
                     dbg = b"overwriting %d bytes from %d in cache/%s"
-                    dbg %= (overwritten, start, _rbcrevs)
+                    dbg %= (current_size - start, start, _rbcrevs)
                     if end < current_size:
                         extra = b" leaving (%d trailing bytes)"
                         extra %= current_size - end
                         dbg += extra
                     dbg += b'\n'
                     repo.ui.debug(dbg)
                 else:
-                    start = 0
-                    dbg = b"resetting content of cache/%s\n" % _rbcrevs
+                    # extra untouched data at the end, lets warn about them
+                    assert start == end  # since don't write anything
+                    dbg = b"cache/%s contains %d unknown trailing bytes\n"
+                    dbg %= (_rbcrevs, current_size - start)
                     repo.ui.debug(dbg)
+
             if start > 0:
                 f.seek(start)
                 f.write(self._rbcrevs.slice(start, end))
             else:
                 f.close()
                 with repo.cachevfs.open(
                     _rbcrevs,
                     b'wb',
                     atomictemp=True,
                 ) as rev_file:
                     rev_file.write(self._rbcrevs.slice(start, end))
         self._rbcrevslen = revs
         self._force_overwrite = False

tests/test-branches.t

@@ -1,1466 +1,1466
 #testcases mmap nommap
 #testcases v2 v3
 
 #if mmap
   $ cat <<EOF >> $HGRCPATH
   > [storage]
   > revbranchcache.mmap=true
   > EOF
 #endif
 
 #if v3
   $ cat <<EOF >> $HGRCPATH
   > [experimental]
   > branch-cache-v3=yes
   > EOF
 #else
   $ cat <<EOF >> $HGRCPATH
   > [experimental]
   > branch-cache-v3=no
   > EOF
 #endif
 
   $ hg init a
   $ cd a
 
 Verify checking branch of nullrev before the cache is created doesnt crash
   $ hg log -r 'branch(.)' -T '{branch}\n'
 
 Basic test
   $ echo 'root' >root
   $ hg add root
   $ hg commit -d '0 0' -m "Adding root node"
 
   $ echo 'a' >a
   $ hg add a
   $ hg branch a
   marked working directory as branch a
   (branches are permanent and global, did you want a bookmark?)
   $ hg commit -d '1 0' -m "Adding a branch"
 
   $ hg branch q
   marked working directory as branch q
   $ echo 'aa' >a
   $ hg branch -C
   reset working directory to branch a
   $ hg commit -d '2 0' -m "Adding to a branch"
 
   $ hg update -C 0
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ echo 'b' >b
   $ hg add b
   $ hg branch b
   marked working directory as branch b
   $ hg commit -d '2 0' -m "Adding b branch"
 
   $ echo 'bh1' >bh1
   $ hg add bh1
   $ hg commit -d '3 0' -m "Adding b branch head 1"
 
   $ hg update -C 2
   1 files updated, 0 files merged, 2 files removed, 0 files unresolved
   $ echo 'bh2' >bh2
   $ hg add bh2
   $ hg commit -d '4 0' -m "Adding b branch head 2"
 
   $ echo 'c' >c
   $ hg add c
   $ hg branch c
   marked working directory as branch c
   $ hg commit -d '5 0' -m "Adding c branch"
 
 reserved names
 
   $ hg branch tip
   abort: the name 'tip' is reserved
   [10]
   $ hg branch null
   abort: the name 'null' is reserved
   [10]
   $ hg branch .
   abort: the name '.' is reserved
   [10]
 
 invalid characters
 
   $ hg branch 'foo:bar'
   abort: ':' cannot be used in a name
   [10]
 
   $ hg branch 'foo
   > bar'
   abort: '\n' cannot be used in a name
   [10]
 
 trailing or leading spaces should be stripped before testing duplicates
 
   $ hg branch 'b '
   abort: a branch of the same name already exists
   (use 'hg update' to switch to it)
   [10]
 
   $ hg branch ' b'
   abort: a branch of the same name already exists
   (use 'hg update' to switch to it)
   [10]
 
 underscores in numeric branch names (issue6737)
 
   $ hg branch 2700_210
   marked working directory as branch 2700_210
 
 verify update will accept invalid legacy branch names
 
   $ hg init test-invalid-branch-name
   $ cd test-invalid-branch-name
   $ hg unbundle -u "$TESTDIR"/bundles/test-invalid-branch-name.hg
   adding changesets
   adding manifests
   adding file changes
   added 3 changesets with 3 changes to 2 files
   new changesets f0e4c7f04036:33c2ceb9310b (3 drafts)
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
 
   $ hg update '"colon:test"'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ cd ..
 
   $ echo 'd' >d
   $ hg add d
   $ hg branch 'a branch name much longer than the default justification used by branches'
   marked working directory as branch a branch name much longer than the default justification used by branches
   $ hg commit -d '6 0' -m "Adding d branch"
 
   $ hg branches
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
   b                              4:aee39cd168d0
   c                              6:589736a22561 (inactive)
   a                              5:d8cbc61dbaa6 (inactive)
   default                        0:19709c5a4e75 (inactive)
 
 -------
 
   $ hg branches -a
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
   b                              4:aee39cd168d0
 
 --- Branch a
 
   $ hg log -b a
   changeset:   5:d8cbc61dbaa6
   branch:      a
   parent:      2:881fe2b92ad0
   user:        test
   date:        Thu Jan 01 00:00:04 1970 +0000
   summary:     Adding b branch head 2
   
   changeset:   2:881fe2b92ad0
   branch:      a
   user:        test
   date:        Thu Jan 01 00:00:02 1970 +0000
   summary:     Adding to a branch
   
   changeset:   1:dd6b440dd85a
   branch:      a
   user:        test
   date:        Thu Jan 01 00:00:01 1970 +0000
   summary:     Adding a branch
   
 
 ---- Branch b
 
   $ hg log -b b
   changeset:   4:aee39cd168d0
   branch:      b
   user:        test
   date:        Thu Jan 01 00:00:03 1970 +0000
   summary:     Adding b branch head 1
   
   changeset:   3:ac22033332d1
   branch:      b
   parent:      0:19709c5a4e75
   user:        test
   date:        Thu Jan 01 00:00:02 1970 +0000
   summary:     Adding b branch
   
 
 ---- going to test branch listing by rev
   $ hg branches -r0
   default                        0:19709c5a4e75 (inactive)
   $ hg branches -qr0
   default
 --- now more than one rev
   $ hg branches -r2:5
   b                              4:aee39cd168d0
   a                              5:d8cbc61dbaa6 (inactive)
   $ hg branches -qr2:5
   b
   a
 ---- going to test branch closing
 
   $ hg branches
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
   b                              4:aee39cd168d0
   c                              6:589736a22561 (inactive)
   a                              5:d8cbc61dbaa6 (inactive)
   default                        0:19709c5a4e75 (inactive)
   $ hg up -C b
   2 files updated, 0 files merged, 4 files removed, 0 files unresolved
   $ echo 'xxx1' >> b
   $ hg commit -d '7 0' -m 'adding cset to branch b'
   $ hg up -C aee39cd168d0
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ echo 'xxx2' >> b
   $ hg commit -d '8 0' -m 'adding head to branch b'
   created new head
   $ echo 'xxx3' >> b
   $ hg commit -d '9 0' -m 'adding another cset to branch b'
   $ hg branches
   b                             10:bfbe841b666e
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
   c                              6:589736a22561 (inactive)
   a                              5:d8cbc61dbaa6 (inactive)
   default                        0:19709c5a4e75 (inactive)
   $ hg heads --closed
   changeset:   10:bfbe841b666e
   branch:      b
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:09 1970 +0000
   summary:     adding another cset to branch b
   
   changeset:   8:eebb944467c9
   branch:      b
   parent:      4:aee39cd168d0
   user:        test
   date:        Thu Jan 01 00:00:07 1970 +0000
   summary:     adding cset to branch b
   
   changeset:   7:10ff5895aa57
   branch:      a branch name much longer than the default justification used by branches
   user:        test
   date:        Thu Jan 01 00:00:06 1970 +0000
   summary:     Adding d branch
   
   changeset:   6:589736a22561
   branch:      c
   user:        test
   date:        Thu Jan 01 00:00:05 1970 +0000
   summary:     Adding c branch
   
   changeset:   5:d8cbc61dbaa6
   branch:      a
   parent:      2:881fe2b92ad0
   user:        test
   date:        Thu Jan 01 00:00:04 1970 +0000
   summary:     Adding b branch head 2
   
   changeset:   0:19709c5a4e75
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     Adding root node
   
   $ hg heads
   changeset:   10:bfbe841b666e
   branch:      b
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:09 1970 +0000
   summary:     adding another cset to branch b
   
   changeset:   8:eebb944467c9
   branch:      b
   parent:      4:aee39cd168d0
   user:        test
   date:        Thu Jan 01 00:00:07 1970 +0000
   summary:     adding cset to branch b
   
   changeset:   7:10ff5895aa57
   branch:      a branch name much longer than the default justification used by branches
   user:        test
   date:        Thu Jan 01 00:00:06 1970 +0000
   summary:     Adding d branch
   
   changeset:   6:589736a22561
   branch:      c
   user:        test
   date:        Thu Jan 01 00:00:05 1970 +0000
   summary:     Adding c branch
   
   changeset:   5:d8cbc61dbaa6
   branch:      a
   parent:      2:881fe2b92ad0
   user:        test
   date:        Thu Jan 01 00:00:04 1970 +0000
   summary:     Adding b branch head 2
   
   changeset:   0:19709c5a4e75
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     Adding root node
   
   $ hg commit -d '9 0' --close-branch -m 'prune bad branch'
   $ hg branches -a
   b                              8:eebb944467c9
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
   $ hg up -C b
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg commit -d '9 0' --close-branch -m 'close this part branch too'
   $ hg commit -d '9 0' --close-branch -m 're-closing this branch'
   abort: current revision is already a branch closing head
   [10]
 
   $ echo foo > b
   $ hg commit -d '9 0' --close-branch -m 're-closing this branch'
 
   $ echo bar > b
   $ hg commit -d '9 0' --close-branch -m 're-closing this branch' bh1
   abort: current revision is already a branch closing head
   [10]
   $ hg commit -d '9 0' --close-branch -m 're-closing this branch' b
 
   $ echo baz > b
   $ hg commit -d '9 0' --close-branch -m 'empty re-closing this branch' -X b
   abort: current revision is already a branch closing head
   [10]
   $ hg revert b
 
   $ hg debugstrip --rev 13: --no-backup
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg revert --all --no-backup
 
   $ hg log -r tip --debug
   changeset:   12:e3d49c0575d8fc2cb1cd6859c747c14f5f6d499f
   branch:      b
   tag:         tip
   phase:       draft
   parent:      8:eebb944467c9fb9651ed232aeaf31b3c0a7fc6c1
   parent:      -1:0000000000000000000000000000000000000000
   manifest:    8:6f9ed32d2b310e391a4f107d5f0f071df785bfee
   user:        test
   date:        Thu Jan 01 00:00:09 1970 +0000
   extra:       branch=b
   extra:       close=1
   description:
   close this part branch too
   
   
 --- b branch should be inactive
 
   $ hg branches
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
   c                              6:589736a22561 (inactive)
   a                              5:d8cbc61dbaa6 (inactive)
   default                        0:19709c5a4e75 (inactive)
   $ hg branches -c
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
   b                             12:e3d49c0575d8 (closed)
   c                              6:589736a22561 (inactive)
   a                              5:d8cbc61dbaa6 (inactive)
   default                        0:19709c5a4e75 (inactive)
   $ hg branches -a
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
   $ hg branches -q
   a branch name much longer than the default justification used by branches
   c
   a
   default
   $ hg heads b
   no open branch heads found on branches b
   [1]
   $ hg heads --closed b
   changeset:   12:e3d49c0575d8
   branch:      b
   tag:         tip
   parent:      8:eebb944467c9
   user:        test
   date:        Thu Jan 01 00:00:09 1970 +0000
   summary:     close this part branch too
   
   changeset:   11:d3f163457ebf
   branch:      b
   user:        test
   date:        Thu Jan 01 00:00:09 1970 +0000
   summary:     prune bad branch
   
   $ echo 'xxx4' >> b
   $ hg commit -d '9 0' -m 'reopen branch with a change'
   reopening closed branch head 12
 
 --- branch b is back in action
 
   $ hg branches -a
   b                             13:e23b5505d1ad
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
 
 ---- test heads listings
 
   $ hg heads
   changeset:   13:e23b5505d1ad
   branch:      b
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:09 1970 +0000
   summary:     reopen branch with a change
   
   changeset:   7:10ff5895aa57
   branch:      a branch name much longer than the default justification used by branches
   user:        test
   date:        Thu Jan 01 00:00:06 1970 +0000
   summary:     Adding d branch
   
   changeset:   6:589736a22561
   branch:      c
   user:        test
   date:        Thu Jan 01 00:00:05 1970 +0000
   summary:     Adding c branch
   
   changeset:   5:d8cbc61dbaa6
   branch:      a
   parent:      2:881fe2b92ad0
   user:        test
   date:        Thu Jan 01 00:00:04 1970 +0000
   summary:     Adding b branch head 2
   
   changeset:   0:19709c5a4e75
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     Adding root node
   
 
 branch default
 
   $ hg heads default
   changeset:   0:19709c5a4e75
   user:        test
   date:        Thu Jan 01 00:00:00 1970 +0000
   summary:     Adding root node
   
 
 branch a
 
   $ hg heads a
   changeset:   5:d8cbc61dbaa6
   branch:      a
   parent:      2:881fe2b92ad0
   user:        test
   date:        Thu Jan 01 00:00:04 1970 +0000
   summary:     Adding b branch head 2
   
   $ hg heads --active a
   no open branch heads found on branches a
   [1]
 
 branch b
 
   $ hg heads b
   changeset:   13:e23b5505d1ad
   branch:      b
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:09 1970 +0000
   summary:     reopen branch with a change
   
   $ hg heads --closed b
   changeset:   13:e23b5505d1ad
   branch:      b
   tag:         tip
   user:        test
   date:        Thu Jan 01 00:00:09 1970 +0000
   summary:     reopen branch with a change
   
   changeset:   11:d3f163457ebf
   branch:      b
   user:        test
   date:        Thu Jan 01 00:00:09 1970 +0000
   summary:     prune bad branch
   
 
 reclose branch
 
   $ hg up -C c
   3 files updated, 0 files merged, 2 files removed, 0 files unresolved
   $ hg commit -d '9 0' --close-branch -m 'reclosing this branch'
   $ hg branches
   b                             13:e23b5505d1ad
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
   a                              5:d8cbc61dbaa6 (inactive)
   default                        0:19709c5a4e75 (inactive)
   $ hg branches --closed
   b                             13:e23b5505d1ad
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
   c                             14:f894c25619d3 (closed)
   a                              5:d8cbc61dbaa6 (inactive)
   default                        0:19709c5a4e75 (inactive)
 
 multihead branch
 
   $ hg up -C default
   0 files updated, 0 files merged, 3 files removed, 0 files unresolved
   $ hg branch m
   marked working directory as branch m
   $ touch m
   $ hg add m
   $ hg commit -d '10 0' -m 'multihead base'
   $ echo "m1" >m
   $ hg commit -d '10 0' -m 'head 1'
   $ hg up -C '.^'
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ echo "m2" >m
   $ hg commit -d '10 0' -m 'head 2'
   created new head
   $ hg log -b m
   changeset:   17:df343b0df04f
   branch:      m
   tag:         tip
   parent:      15:f3447637f53e
   user:        test
   date:        Thu Jan 01 00:00:10 1970 +0000
   summary:     head 2
   
   changeset:   16:a58ca5d3bdf3
   branch:      m
   user:        test
   date:        Thu Jan 01 00:00:10 1970 +0000
   summary:     head 1
   
   changeset:   15:f3447637f53e
   branch:      m
   parent:      0:19709c5a4e75
   user:        test
   date:        Thu Jan 01 00:00:10 1970 +0000
   summary:     multihead base
   
   $ hg heads --topo m
   changeset:   17:df343b0df04f
   branch:      m
   tag:         tip
   parent:      15:f3447637f53e
   user:        test
   date:        Thu Jan 01 00:00:10 1970 +0000
   summary:     head 2
   
   changeset:   16:a58ca5d3bdf3
   branch:      m
   user:        test
   date:        Thu Jan 01 00:00:10 1970 +0000
   summary:     head 1
   
   $ hg branches
   m                             17:df343b0df04f
   b                             13:e23b5505d1ad
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
   a                              5:d8cbc61dbaa6 (inactive)
   default                        0:19709c5a4e75 (inactive)
 
 partially merge multihead branch
 
   $ hg up -C default
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg branch md
   marked working directory as branch md
   $ hg merge m
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   (branch merge, don't forget to commit)
   $ hg commit -d '11 0' -m 'merge head 2'
   $ hg heads --topo m
   changeset:   16:a58ca5d3bdf3
   branch:      m
   user:        test
   date:        Thu Jan 01 00:00:10 1970 +0000
   summary:     head 1
   
   $ hg branches
   md                            18:c914c99f1fbb
   m                             17:df343b0df04f
   b                             13:e23b5505d1ad
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
   a                              5:d8cbc61dbaa6 (inactive)
   default                        0:19709c5a4e75 (inactive)
 
 partially close multihead branch
 
   $ hg up -C a58ca5d3bdf3
   1 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ hg commit -d '12 0' -m 'close head 1' --close-branch
   $ hg heads --topo m
   changeset:   19:cd21a80baa3d
   branch:      m
   tag:         tip
   parent:      16:a58ca5d3bdf3
   user:        test
   date:        Thu Jan 01 00:00:12 1970 +0000
   summary:     close head 1
   
   $ hg branches
   md                            18:c914c99f1fbb
   b                             13:e23b5505d1ad
   a branch name much longer than the default justification used by branches 7:10ff5895aa57
   m                             17:df343b0df04f (inactive)
   a                              5:d8cbc61dbaa6 (inactive)
   default                        0:19709c5a4e75 (inactive)
 
 default branch colors:
 
   $ cat <<EOF >> $HGRCPATH
   > [extensions]
   > color =
   > [color]
   > mode = ansi
   > EOF
 
   $ hg up -C b
   2 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg branches --color=always
   \x1b[0;0mmd\x1b[0m\x1b[0;33m                            18:c914c99f1fbb\x1b[0m (esc)
   \x1b[0;32mb\x1b[0m\x1b[0;33m                             13:e23b5505d1ad\x1b[0m (esc)
   \x1b[0;0ma branch name much longer than the default justification used by branches\x1b[0m\x1b[0;33m 7:10ff5895aa57\x1b[0m (esc)
   \x1b[0;0mm\x1b[0m\x1b[0;33m                             17:df343b0df04f\x1b[0m (inactive) (esc)
   \x1b[0;0ma\x1b[0m\x1b[0;33m                              5:d8cbc61dbaa6\x1b[0m (inactive) (esc)
   \x1b[0;0mdefault\x1b[0m\x1b[0;33m                        0:19709c5a4e75\x1b[0m (inactive) (esc)
 
 default closed branch color:
 
   $ hg branches --color=always --closed
   \x1b[0;0mmd\x1b[0m\x1b[0;33m                            18:c914c99f1fbb\x1b[0m (esc)
   \x1b[0;32mb\x1b[0m\x1b[0;33m                             13:e23b5505d1ad\x1b[0m (esc)
   \x1b[0;0ma branch name much longer than the default justification used by branches\x1b[0m\x1b[0;33m 7:10ff5895aa57\x1b[0m (esc)
   \x1b[0;0mm\x1b[0m\x1b[0;33m                             17:df343b0df04f\x1b[0m (inactive) (esc)
   \x1b[0;30;1mc\x1b[0m\x1b[0;33m                             14:f894c25619d3\x1b[0m (closed) (esc)
   \x1b[0;0ma\x1b[0m\x1b[0;33m                              5:d8cbc61dbaa6\x1b[0m (inactive) (esc)
   \x1b[0;0mdefault\x1b[0m\x1b[0;33m                        0:19709c5a4e75\x1b[0m (inactive) (esc)
 
   $ cat <<EOF >> $HGRCPATH
   > [extensions]
   > color =
   > [color]
   > branches.active = green
   > branches.closed = blue
   > branches.current = red
   > branches.inactive = magenta
   > log.changeset = cyan
   > EOF
 
 custom branch colors:
 
   $ hg branches --color=always
   \x1b[0;32mmd\x1b[0m\x1b[0;36m                            18:c914c99f1fbb\x1b[0m (esc)
   \x1b[0;31mb\x1b[0m\x1b[0;36m                             13:e23b5505d1ad\x1b[0m (esc)
   \x1b[0;32ma branch name much longer than the default justification used by branches\x1b[0m\x1b[0;36m 7:10ff5895aa57\x1b[0m (esc)
   \x1b[0;35mm\x1b[0m\x1b[0;36m                             17:df343b0df04f\x1b[0m (inactive) (esc)
   \x1b[0;35ma\x1b[0m\x1b[0;36m                              5:d8cbc61dbaa6\x1b[0m (inactive) (esc)
   \x1b[0;35mdefault\x1b[0m\x1b[0;36m                        0:19709c5a4e75\x1b[0m (inactive) (esc)
 
 custom closed branch color:
 
   $ hg branches --color=always --closed
   \x1b[0;32mmd\x1b[0m\x1b[0;36m                            18:c914c99f1fbb\x1b[0m (esc)
   \x1b[0;31mb\x1b[0m\x1b[0;36m                             13:e23b5505d1ad\x1b[0m (esc)
   \x1b[0;32ma branch name much longer than the default justification used by branches\x1b[0m\x1b[0;36m 7:10ff5895aa57\x1b[0m (esc)
   \x1b[0;35mm\x1b[0m\x1b[0;36m                             17:df343b0df04f\x1b[0m (inactive) (esc)
   \x1b[0;34mc\x1b[0m\x1b[0;36m                             14:f894c25619d3\x1b[0m (closed) (esc)
   \x1b[0;35ma\x1b[0m\x1b[0;36m                              5:d8cbc61dbaa6\x1b[0m (inactive) (esc)
   \x1b[0;35mdefault\x1b[0m\x1b[0;36m                        0:19709c5a4e75\x1b[0m (inactive) (esc)
 
 template output:
 
   $ hg branches -Tjson --closed
   [
    {
     "active": true,
     "branch": "md",
     "closed": false,
     "current": false,
     "node": "c914c99f1fbb2b1d785a0a939ed3f67275df18e9",
     "rev": 18
    },
    {
     "active": true,
     "branch": "b",
     "closed": false,
     "current": true,
     "node": "e23b5505d1ad24aab6f84fd8c7cb8cd8e5e93be0",
     "rev": 13
    },
    {
     "active": true,
     "branch": "a branch name much longer than the default justification used by branches",
     "closed": false,
     "current": false,
     "node": "10ff5895aa5793bd378da574af8cec8ea408d831",
     "rev": 7
    },
    {
     "active": false,
     "branch": "m",
     "closed": false,
     "current": false,
     "node": "df343b0df04feb2a946cd4b6e9520e552fef14ee",
     "rev": 17
    },
    {
     "active": false,
     "branch": "c",
     "closed": true,
     "current": false,
     "node": "f894c25619d3f1484639d81be950e0a07bc6f1f6",
     "rev": 14
    },
    {
     "active": false,
     "branch": "a",
     "closed": false,
     "current": false,
     "node": "d8cbc61dbaa6dc817175d1e301eecb863f280832",
     "rev": 5
    },
    {
     "active": false,
     "branch": "default",
     "closed": false,
     "current": false,
     "node": "19709c5a4e75bf938f8e349aff97438539bb729e",
     "rev": 0
    }
   ]
 
   $ hg branches --closed -T '{if(closed, "{branch}\n")}'
   c
 
   $ hg branches -T '{word(0, branch)}: {desc|firstline}\n'
   md: merge head 2
   b: reopen branch with a change
   a: Adding d branch
   m: head 2
   a: Adding b branch head 2
   default: Adding root node
 
   $ cat <<'EOF' > "$TESTTMP/map-myjson"
   > docheader = '\{\n'
   > docfooter = '\n}\n'
   > separator = ',\n'
   > branches = ' {dict(branch, node|short)|json}'
   > EOF
   $ hg branches -T "$TESTTMP/map-myjson"
   {
    {"branch": "md", "node": "c914c99f1fbb"},
    {"branch": "b", "node": "e23b5505d1ad"},
    {"branch": "a branch *", "node": "10ff5895aa57"}, (glob)
    {"branch": "m", "node": "df343b0df04f"},
    {"branch": "a", "node": "d8cbc61dbaa6"},
    {"branch": "default", "node": "19709c5a4e75"}
   }
 
   $ cat <<'EOF' >> .hg/hgrc
   > [templates]
   > myjson = ' {dict(branch, node|short)|json}'
   > myjson:docheader = '\{\n'
   > myjson:docfooter = '\n}\n'
   > myjson:separator = ',\n'
   > EOF
   $ hg branches -T myjson
   {
    {"branch": "md", "node": "c914c99f1fbb"},
    {"branch": "b", "node": "e23b5505d1ad"},
    {"branch": "a branch *", "node": "10ff5895aa57"}, (glob)
    {"branch": "m", "node": "df343b0df04f"},
    {"branch": "a", "node": "d8cbc61dbaa6"},
    {"branch": "default", "node": "19709c5a4e75"}
   }
 
   $ cat <<'EOF' >> .hg/hgrc
   > [templates]
   > :docheader = 'should not be selected as a docheader for literal templates\n'
   > EOF
   $ hg branches -T '{branch}\n'
   md
   b
   a branch name much longer than the default justification used by branches
   m
   a
   default
 
 Tests of revision branch name caching
 
 We rev branch cache is updated automatically. In these tests we use a trick to
 trigger rebuilds. We remove the branch head cache and run 'hg head' to cause a
 rebuild that also will populate the rev branch cache.
 
 revision branch cache is created when building the branch head cache
   $ rm -rf .hg/cache; hg head a -T '{rev}\n'
   5
   $ f --hexdump --size .hg/cache/rbc-*
   .hg/cache/rbc-names-v2: size=92
   0000: 64 65 66 61 75 6c 74 00 61 00 62 00 63 00 61 20 |default.a.b.c.a |
   0010: 62 72 61 6e 63 68 20 6e 61 6d 65 20 6d 75 63 68 |branch name much|
   0020: 20 6c 6f 6e 67 65 72 20 74 68 61 6e 20 74 68 65 | longer than the|
   0030: 20 64 65 66 61 75 6c 74 20 6a 75 73 74 69 66 69 | default justifi|
   0040: 63 61 74 69 6f 6e 20 75 73 65 64 20 62 79 20 62 |cation used by b|
   0050: 72 61 6e 63 68 65 73 00 6d 00 6d 64             |ranches.m.md|
   .hg/cache/rbc-revs-v2: size=160
   0000: 19 70 9c 5a 00 00 00 00 dd 6b 44 0d 00 00 00 01 |.p.Z.....kD.....|
   0010: 88 1f e2 b9 00 00 00 01 ac 22 03 33 00 00 00 02 |.........".3....|
   0020: ae e3 9c d1 00 00 00 02 d8 cb c6 1d 00 00 00 01 |................|
   0030: 58 97 36 a2 00 00 00 03 10 ff 58 95 00 00 00 04 |X.6.......X.....|
   0040: ee bb 94 44 00 00 00 02 5f 40 61 bb 00 00 00 02 |...D...._@a.....|
   0050: bf be 84 1b 00 00 00 02 d3 f1 63 45 80 00 00 02 |..........cE....|
   0060: e3 d4 9c 05 80 00 00 02 e2 3b 55 05 00 00 00 02 |.........;U.....|
   0070: f8 94 c2 56 80 00 00 03 f3 44 76 37 00 00 00 05 |...V.....Dv7....|
   0080: a5 8c a5 d3 00 00 00 05 df 34 3b 0d 00 00 00 05 |.........4;.....|
   0090: c9 14 c9 9f 00 00 00 06 cd 21 a8 0b 80 00 00 05 |.........!......|
 
 no errors when revbranchcache is not writable
 
   $ echo >> .hg/cache/rbc-revs-v2
   $ mv .hg/cache/rbc-revs-v2 .hg/cache/rbc-revs-v2_
   $ mkdir .hg/cache/rbc-revs-v2
   $ rm -f .hg/cache/branch* && hg head a -T '{rev}\n'
   5
   $ rmdir .hg/cache/rbc-revs-v2
   $ mv .hg/cache/rbc-revs-v2_ .hg/cache/rbc-revs-v2
 
 no errors when wlock cannot be acquired
 
 #if unix-permissions
   $ mv .hg/cache/rbc-revs-v2 .hg/cache/rbc-revs-v2_
   $ rm -f .hg/cache/branch*
   $ chmod 555 .hg
   $ hg head a -T '{rev}\n'
   5
   $ chmod 755 .hg
   $ mv .hg/cache/rbc-revs-v2_ .hg/cache/rbc-revs-v2
 #endif
 
 recovery from invalid cache revs file with trailing data
   $ echo >> .hg/cache/rbc-revs-v2
   $ rm -f .hg/cache/branch* && hg head a -T '{rev}\n' --debug
   5
-  overwriting 0 bytes from 160 in cache/rbc-revs-v2 leaving (2 trailing bytes)
+  cache/rbc-revs-v2 contains 2 unknown trailing bytes
   $ f --size .hg/cache/rbc-revs*
   .hg/cache/rbc-revs-v2: size=162
 
 recovery from invalid cache file with partial last record
   $ mv .hg/cache/rbc-revs-v2 .
   $ f -qDB 119 rbc-revs-v2 > .hg/cache/rbc-revs-v2
   $ f --size .hg/cache/rbc-revs*
   .hg/cache/rbc-revs-v2: size=119
   $ rm -f .hg/cache/branch* && hg head a -T '{rev}\n' --debug
   5
   resetting content of cache/rbc-revs-v2
   $ f --size .hg/cache/rbc-revs*
   .hg/cache/rbc-revs-v2: size=160
 
 recovery from invalid cache file with missing record - no truncation
   $ mv .hg/cache/rbc-revs-v2 .
   $ f -qDB 112 rbc-revs-v2 > .hg/cache/rbc-revs-v2
   $ rm -f .hg/cache/branch* && hg head a -T '{rev}\n' --debug
   5
   $ f --size .hg/cache/rbc-revs*
   .hg/cache/rbc-revs-v2: size=160
 
 recovery from invalid cache file with some bad records
   $ mv .hg/cache/rbc-revs-v2 .
   $ f -qDB 8 rbc-revs-v2 > .hg/cache/rbc-revs-v2
   $ f --size .hg/cache/rbc-revs*
   .hg/cache/rbc-revs-v2: size=8
   $ f -qDB 112 rbc-revs-v2 >> .hg/cache/rbc-revs-v2
   $ f --size .hg/cache/rbc-revs*
   .hg/cache/rbc-revs-v2: size=120
   $ hg log -r 'branch(.)' -T '{rev} ' --debug
   history modification detected - truncating revision branch cache to revision * (glob)
   history modification detected - truncating revision branch cache to revision 1
   3 4 8 9 10 11 12 13 resetting content of cache/rbc-revs-v2
   $ rm -f .hg/cache/branch* && hg head a -T '{rev}\n' --debug
   5
   resetting content of cache/rbc-revs-v2
   $ f --size --hexdump --bytes=16 .hg/cache/rbc-revs*
   .hg/cache/rbc-revs-v2: size=160
   0000: 19 70 9c 5a 00 00 00 00 dd 6b 44 0d 00 00 00 01 |.p.Z.....kD.....|
 
 Smoothly reuse "v1" format if no v2 exists
 ------------------------------------------
 
 read only operation with valid data
 (actively rewrite data)
 
   $ rm .hg/cache/rbc-names-v2
   $ rm .hg/cache/rbc-revs-v2
   $ rm .hg/cache/branch*
   $ hg head a -T '{rev}\n' --debug
   5
   $ mv .hg/cache/rbc-names-v2 .hg/cache/rbc-names-v1
   $ mv .hg/cache/rbc-revs-v2 .hg/cache/rbc-revs-v1
   $ rm .hg/cache/branch*
   $ hg head a -T '{rev}\n' --debug
   5
   $ f --size .hg/cache/rbc-*-*
   .hg/cache/rbc-names-v1: size=92
   .hg/cache/rbc-names-v2: size=92
   .hg/cache/rbc-revs-v1: size=160
   .hg/cache/rbc-revs-v2: size=160
 
 
 Write operation write a full v2 files
 
   $ mv .hg/cache/rbc-names-v2 .hg/cache/rbc-names-v1
   $ mv .hg/cache/rbc-revs-v2 .hg/cache/rbc-revs-v1
   $ f --size .hg/cache/rbc-*
   .hg/cache/rbc-names-v1: size=92
   .hg/cache/rbc-revs-v1: size=160
   $ hg branch not-here-for-long
   marked working directory as branch not-here-for-long
   $ hg ci -m not-long --debug
   reusing manifest from p1 (no file change)
   committing changelog
   updating the branch cache
   committed changeset * (glob)
   $ f --size .hg/cache/rbc-*
   .hg/cache/rbc-names-v1: size=92
   .hg/cache/rbc-names-v2: size=110
   .hg/cache/rbc-revs-v1: size=160
   .hg/cache/rbc-revs-v2: size=168
 
 So does explicit cache upgrade
   $ mv .hg/cache/rbc-names-v2 .hg/cache/rbc-names-v1
   $ mv .hg/cache/rbc-revs-v2 .hg/cache/rbc-revs-v1
   $ f --size .hg/cache/rbc-*
   .hg/cache/rbc-names-v1: size=110
   .hg/cache/rbc-revs-v1: size=168
   $ hg debugupdatecache
   $ f --size .hg/cache/rbc-*
   .hg/cache/rbc-names-v1: size=110
   .hg/cache/rbc-names-v2: size=110
   .hg/cache/rbc-revs-v1: size=168
   .hg/cache/rbc-revs-v2: size=168
 
 With invalid v1 data, we rewrite it too (as v2)
 
   $ cp .hg/cache/rbc-names-v2 .hg/cache/rbc-names-v1
   $ mv .hg/cache/rbc-names-v2 .hg/cache/rbc-revs-v1
   $ rm .hg/cache/rbc-revs-v2
   $ rm .hg/cache/branch*
   $ 
   $ hg head a -T '{rev}\n' --debug
   history modification detected - truncating revision branch cache to revision 0
   5
   $ f --size .hg/cache/rbc-*-*
   .hg/cache/rbc-names-v1: size=110
   .hg/cache/rbc-names-v2: size=110
   .hg/cache/rbc-revs-v1: size=110
   .hg/cache/rbc-revs-v2: size=168
 
 cleanup
 
   $ hg up -qr '.^'
   $ hg rollback -qf
   $ rm .hg/cache/*
   $ hg debugupdatecache
   $ f --size .hg/cache/rbc-*
   .hg/cache/rbc-names-v2: size=92
   .hg/cache/rbc-revs-v2: size=160
 
 cache is updated when committing
   $ hg branch i-will-regret-this
   marked working directory as branch i-will-regret-this
   $ hg ci -m regrets
   $ f --size .hg/cache/rbc-*
   .hg/cache/rbc-names-v2: size=111
   .hg/cache/rbc-revs-v2: size=168
 
 update after rollback - the cache will be correct but rbc-names will will still
 contain the branch name even though it no longer is used
   $ hg up -qr '.^'
   $ hg rollback -qf
   $ f --size .hg/cache/rbc-names-*
   .hg/cache/rbc-names-v2: size=111
   $ grep "i-will-regret-this" .hg/cache/rbc-names-* > /dev/null
   $ f --size .hg/cache/rbc-revs-*
   .hg/cache/rbc-revs-v2: size=168
 
 cache is updated/truncated when stripping - it is thus very hard to get in a
 situation where the cache is out of sync and the hash check detects it
   $ hg --config extensions.strip= strip -r tip --nob
   $ f --size .hg/cache/rbc-revs*
   .hg/cache/rbc-revs-v2: size=152
 
 cache is rebuilt when corruption is detected
   $ echo > .hg/cache/rbc-names-v2
   $ hg log -r '5:&branch(.)' -T '{rev} ' --debug
   referenced branch names not found - rebuilding revision branch cache from scratch
   8 9 10 11 12 13 resetting content of rbc-names-v2
   $ f --size .hg/cache/rbc-names-*
   .hg/cache/rbc-names-v2: size=84
   $ grep "i-will-regret-this" .hg/cache/rbc-names-* > /dev/null
   [1]
   $ f --size .hg/cache/rbc-revs-*
   .hg/cache/rbc-revs-v2: size=152
 
 Test that cache files are created and grows correctly:
 
   $ rm .hg/cache/rbc*
   $ hg log -r "5 & branch(5)" -T "{rev}\n"
   5
 
 (here v3 is querying branch info for heads so it warm much more of the cache)
 
 #if v2
   $ f --size .hg/cache/rbc-*
   .hg/cache/rbc-names-v2: size=1
   .hg/cache/rbc-revs-v2: size=48
 #else
   $ f --size .hg/cache/rbc-*
   .hg/cache/rbc-names-v2: size=84
   .hg/cache/rbc-revs-v2: size=152
 #endif
 
   $ cd ..
 
 Test for multiple incorrect branch cache entries:
 
   $ hg init b
   $ cd b
   $ touch f
   $ hg ci -Aqmf
   $ echo >> f
   $ hg ci -Amf
   $ hg branch -q branch
   $ hg ci -Amf
 
 #if v2
 
   $ f --size --sha256 .hg/cache/rbc-*
   .hg/cache/rbc-names-v2: size=14, sha256=d376f7eea9a7e28fac6470e78dae753c81a5543c9ad436e96999590e004a281c
   .hg/cache/rbc-revs-v2: size=24, sha256=ec89032fd4e66e7282cb6e403848c681a855a9c36c6b44d19179218553b78779
 
   $ : > .hg/cache/rbc-revs-v2
 
 No superfluous rebuilding of cache:
   $ hg log -r "branch(null)&branch(branch)" --debug
   $ f --size --sha256 .hg/cache/rbc-*
   .hg/cache/rbc-names-v2: size=14, sha256=d376f7eea9a7e28fac6470e78dae753c81a5543c9ad436e96999590e004a281c
   .hg/cache/rbc-revs-v2: size=24, sha256=ec89032fd4e66e7282cb6e403848c681a855a9c36c6b44d19179218553b78779
 #endif
 
   $ cd ..
 
 Test to make sure that `--close-branch` only works on a branch head:
 --------------------------------------------------------------------
   $ hg init closebranch
   $ cd closebranch
   $ for ch in a b c; do
   > echo $ch > $ch
   > hg add $ch
   > hg ci -m "added "$ch
   > done;
 
   $ hg up -r "desc('added b')"
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
 
 trying to close branch from a cset which is not a branch head
 it should abort:
   $ hg ci -m "closing branch" --close-branch
   abort: can only close branch heads
   (use --force-close-branch to close branch from a non-head changeset)
   [10]
 
   $ hg up 0
   0 files updated, 0 files merged, 1 files removed, 0 files unresolved
   $ hg log -GT "{rev}: {node|short} {desc|firstline}\n\t{branch}\n\n"
   o  2: 155349b645be added c
   |  	default
   |
   o  1: 5f6d8a4bf34a added b
   |  	default
   |
   @  0: 9092f1db7931 added a
      	default
   
 Test --force-close-branch to close a branch from a non-head changeset:
 ---------------------------------------------------------------------
 
   $ hg show stack --config extensions.show=
     o  1553 added c
     o  5f6d added b
     @  9092 added a
 
   $ hg ci -m "branch closed" --close-branch
   abort: can only close branch heads
   (use --force-close-branch to close branch from a non-head changeset)
   [10]
 
   $ hg ci -m "branch closed" --force-close-branch
   created new head
   $ cd ..
 
 Test various special cases for the branchmap
 --------------------------------------------
 
 Basic fork of the same branch
 
   $ hg init branchmap-testing1
   $ cd branchmap-testing1
   $ hg debugbuild '@A . :base . :p1 *base /p1'
   $ hg log -G
   o    changeset:   3:71ca9a6d524e
   |\   branch:      A
   | |  tag:         tip
   | |  parent:      2:a3b807b3ff0b
   | |  parent:      1:99ba08759bc7
   | |  user:        debugbuilddag
   | |  date:        Thu Jan 01 00:00:03 1970 +0000
   | |  summary:     r3
   | |
   | o  changeset:   2:a3b807b3ff0b
   | |  branch:      A
   | |  parent:      0:2ab8003a1750
   | |  user:        debugbuilddag
   | |  date:        Thu Jan 01 00:00:02 1970 +0000
   | |  summary:     r2
   | |
   o |  changeset:   1:99ba08759bc7
   |/   branch:      A
   |    tag:         p1
   |    user:        debugbuilddag
   |    date:        Thu Jan 01 00:00:01 1970 +0000
   |    summary:     r1
   |
   o  changeset:   0:2ab8003a1750
      branch:      A
      tag:         base
      user:        debugbuilddag
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     r0
   
   $ hg branches
   A                              3:71ca9a6d524e
   $ hg clone -r 1 -r 2 . ../branchmap-testing1-clone
   adding changesets
   adding manifests
   adding file changes
   added 3 changesets with 0 changes to 0 files (+1 heads)
   new changesets 2ab8003a1750:a3b807b3ff0b
   updating to branch A
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ cd ../branchmap-testing1-clone
   $ hg pull ../branchmap-testing1
   pulling from ../branchmap-testing1
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 1 changesets with 0 changes to 0 files (-1 heads)
   new changesets 71ca9a6d524e
   (run 'hg update' to get a working copy)
   $ hg branches
   A                              3:71ca9a6d524e
   $ cd ..
 
 Switching to a different branch and back
 
   $ hg init branchmap-testing2
   $ cd branchmap-testing2
   $ hg debugbuild '@A . @B . @A .'
   $ hg log -G
   o  changeset:   2:9699e9f260b5
   |  branch:      A
   |  tag:         tip
   |  user:        debugbuilddag
   |  date:        Thu Jan 01 00:00:02 1970 +0000
   |  summary:     r2
   |
   o  changeset:   1:0bc7d348d965
   |  branch:      B
   |  user:        debugbuilddag
   |  date:        Thu Jan 01 00:00:01 1970 +0000
   |  summary:     r1
   |
   o  changeset:   0:2ab8003a1750
      branch:      A
      user:        debugbuilddag
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     r0
   
   $ hg branches
   A                              2:9699e9f260b5
   B                              1:0bc7d348d965 (inactive)
   $ hg clone -r 1 . ../branchmap-testing2-clone
   adding changesets
   adding manifests
   adding file changes
   added 2 changesets with 0 changes to 0 files
   new changesets 2ab8003a1750:0bc7d348d965
   updating to branch B
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ cd ../branchmap-testing2-clone
   $ hg pull ../branchmap-testing2
   pulling from ../branchmap-testing2
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 1 changesets with 0 changes to 0 files
   new changesets 9699e9f260b5
   (run 'hg update' to get a working copy)
   $ hg branches
   A                              2:9699e9f260b5
   B                              1:0bc7d348d965 (inactive)
   $ cd ..
 
 A fork on a branch switching to a different branch and back
 is still collecting the fork.
 
   $ hg init branchmap-testing3
   $ cd branchmap-testing3
   $ hg debugbuild '@A . :base . :p1 *base @B . @A /p1'
   $ hg log -G
   o    changeset:   4:3614a1711d23
   |\   branch:      A
   | |  tag:         tip
   | |  parent:      3:e9c8abcf65aa
   | |  parent:      1:99ba08759bc7
   | |  user:        debugbuilddag
   | |  date:        Thu Jan 01 00:00:04 1970 +0000
   | |  summary:     r4
   | |
   | o  changeset:   3:e9c8abcf65aa
   | |  branch:      B
   | |  user:        debugbuilddag
   | |  date:        Thu Jan 01 00:00:03 1970 +0000
   | |  summary:     r3
   | |
   | o  changeset:   2:a3b807b3ff0b
   | |  branch:      A
   | |  parent:      0:2ab8003a1750
   | |  user:        debugbuilddag
   | |  date:        Thu Jan 01 00:00:02 1970 +0000
   | |  summary:     r2
   | |
   o |  changeset:   1:99ba08759bc7
   |/   branch:      A
   |    tag:         p1
   |    user:        debugbuilddag
   |    date:        Thu Jan 01 00:00:01 1970 +0000
   |    summary:     r1
   |
   o  changeset:   0:2ab8003a1750
      branch:      A
      tag:         base
      user:        debugbuilddag
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     r0
   
   $ hg branches
   A                              4:3614a1711d23
   B                              3:e9c8abcf65aa (inactive)
   $ hg clone -r 1 -r 3 . ../branchmap-testing3-clone
   adding changesets
   adding manifests
   adding file changes
   added 4 changesets with 0 changes to 0 files (+1 heads)
   new changesets 2ab8003a1750:e9c8abcf65aa
   updating to branch A
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ cd ../branchmap-testing3-clone
   $ hg pull ../branchmap-testing3
   pulling from ../branchmap-testing3
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 1 changesets with 0 changes to 0 files (-1 heads)
   new changesets 3614a1711d23
   (run 'hg update' to get a working copy)
   $ hg branches
   A                              4:3614a1711d23
   B                              3:e9c8abcf65aa (inactive)
   $ cd ..
 
 Intermediary parents are on different branches.
 
   $ hg init branchmap-testing4
   $ cd branchmap-testing4
   $ hg debugbuild '@A . @B :base . @A :p1 *base @C . @A /p1'
   $ hg log -G
   o    changeset:   4:4bf67499b70a
   |\   branch:      A
   | |  tag:         tip
   | |  parent:      3:4a546028fa8f
   | |  parent:      1:0bc7d348d965
   | |  user:        debugbuilddag
   | |  date:        Thu Jan 01 00:00:04 1970 +0000
   | |  summary:     r4
   | |
   | o  changeset:   3:4a546028fa8f
   | |  branch:      C
   | |  user:        debugbuilddag
   | |  date:        Thu Jan 01 00:00:03 1970 +0000
   | |  summary:     r3
   | |
   | o  changeset:   2:a3b807b3ff0b
   | |  branch:      A
   | |  parent:      0:2ab8003a1750
   | |  user:        debugbuilddag
   | |  date:        Thu Jan 01 00:00:02 1970 +0000
   | |  summary:     r2
   | |
   o |  changeset:   1:0bc7d348d965
   |/   branch:      B
   |    tag:         p1
   |    user:        debugbuilddag
   |    date:        Thu Jan 01 00:00:01 1970 +0000
   |    summary:     r1
   |
   o  changeset:   0:2ab8003a1750
      branch:      A
      tag:         base
      user:        debugbuilddag
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     r0
   
   $ hg branches
   A                              4:4bf67499b70a
   C                              3:4a546028fa8f (inactive)
   B                              1:0bc7d348d965 (inactive)
   $ hg clone -r 1 -r 3 . ../branchmap-testing4-clone
   adding changesets
   adding manifests
   adding file changes
   added 4 changesets with 0 changes to 0 files (+1 heads)
   new changesets 2ab8003a1750:4a546028fa8f
   updating to branch B
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
   $ cd ../branchmap-testing4-clone
   $ hg pull ../branchmap-testing4
   pulling from ../branchmap-testing4
   searching for changes
   adding changesets
   adding manifests
   adding file changes
   added 1 changesets with 0 changes to 0 files (-1 heads)
   new changesets 4bf67499b70a
   (run 'hg update' to get a working copy)
   $ hg branches
   A                              4:4bf67499b70a
   C                              3:4a546028fa8f (inactive)
   B                              1:0bc7d348d965 (inactive)
   $ cd ..
 
 Check that the cache are not written too early
 ----------------------------------------------
 
   $ hg log -R branchmap-testing1 -G
   o    changeset:   3:71ca9a6d524e
   |\   branch:      A
   | |  tag:         tip
   | |  parent:      2:a3b807b3ff0b
   | |  parent:      1:99ba08759bc7
   | |  user:        debugbuilddag
   | |  date:        Thu Jan 01 00:00:03 1970 +0000
   | |  summary:     r3
   | |
   | o  changeset:   2:a3b807b3ff0b
   | |  branch:      A
   | |  parent:      0:2ab8003a1750
   | |  user:        debugbuilddag
   | |  date:        Thu Jan 01 00:00:02 1970 +0000
   | |  summary:     r2
   | |
   o |  changeset:   1:99ba08759bc7
   |/   branch:      A
   |    tag:         p1
   |    user:        debugbuilddag
   |    date:        Thu Jan 01 00:00:01 1970 +0000
   |    summary:     r1
   |
   o  changeset:   0:2ab8003a1750
      branch:      A
      tag:         base
      user:        debugbuilddag
      date:        Thu Jan 01 00:00:00 1970 +0000
      summary:     r0
   
   $ hg bundle -R branchmap-testing1 --base 1 bundle.hg --rev 'head()'
   2 changesets found
 
 Unbundling revision should warm the served cache
 
   $ hg clone branchmap-testing1 --rev 1 branchmap-update-01
   adding changesets
   adding manifests
   adding file changes
   added 2 changesets with 0 changes to 0 files
   new changesets 2ab8003a1750:99ba08759bc7
   updating to branch A
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
 #if v3
   $ cat branchmap-update-01/.hg/cache/branch3-exp-base
   tip-node=99ba08759bc7f6fdbe5304e83d0387f35c082479 tip-rev=1 topo-mode=pure
   A
 #else
   $ cat branchmap-update-01/.hg/cache/branch2-base
   99ba08759bc7f6fdbe5304e83d0387f35c082479 1
   99ba08759bc7f6fdbe5304e83d0387f35c082479 o A
 #endif
   $ hg -R branchmap-update-01 unbundle bundle.hg
   adding changesets
   adding manifests
   adding file changes
   added 2 changesets with 0 changes to 0 files
   new changesets a3b807b3ff0b:71ca9a6d524e (2 drafts)
   (run 'hg update' to get a working copy)
 #if v3
   $ cat branchmap-update-01/.hg/cache/branch3-exp-served
   tip-node=71ca9a6d524ed3c2a215119b2086ac3b8c4c8286 tip-rev=3 topo-mode=pure
   A
 #else
   $ cat branchmap-update-01/.hg/cache/branch2-served
   71ca9a6d524ed3c2a215119b2086ac3b8c4c8286 3
   71ca9a6d524ed3c2a215119b2086ac3b8c4c8286 o A
 #endif
 
 aborted Unbundle should not update the on disk cache
 
   $ cat >> simplehook.py << EOF
   > import sys
   > from mercurial import node
   > from mercurial import branchmap
   > def hook(ui, repo, *args, **kwargs):
   >     s = repo.filtered(b"served")
   >     s.branchmap()
   >     return 1
   > EOF
   $ hg clone branchmap-testing1 --rev 1 branchmap-update-02
   adding changesets
   adding manifests
   adding file changes
   added 2 changesets with 0 changes to 0 files
   new changesets 2ab8003a1750:99ba08759bc7
   updating to branch A
   0 files updated, 0 files merged, 0 files removed, 0 files unresolved
 
 #if v3
   $ cat branchmap-update-02/.hg/cache/branch3-exp-base
   tip-node=99ba08759bc7f6fdbe5304e83d0387f35c082479 tip-rev=1 topo-mode=pure
   A
 #else
   $ cat branchmap-update-02/.hg/cache/branch2-base
   99ba08759bc7f6fdbe5304e83d0387f35c082479 1
   99ba08759bc7f6fdbe5304e83d0387f35c082479 o A
 #endif
   $ hg -R branchmap-update-02 unbundle bundle.hg --config "hooks.pretxnclose=python:$TESTTMP/simplehook.py:hook"
   adding changesets
   adding manifests
   adding file changes
   transaction abort!
   rollback completed
   abort: pretxnclose hook failed
   [40]
 #if v3
   $ cat branchmap-update-02/.hg/cache/branch3-exp-base
   tip-node=99ba08759bc7f6fdbe5304e83d0387f35c082479 tip-rev=1 topo-mode=pure
   A
 #else
   $ cat branchmap-update-02/.hg/cache/branch2-base
   99ba08759bc7f6fdbe5304e83d0387f35c082479 1
   99ba08759bc7f6fdbe5304e83d0387f35c082479 o A
 #endif