view tests/test-bookmarks.t @ 25757:4d1382fd96ff

context: write dirstate out explicitly at the end of markcommitted

To detect change of a file without redundant comparison of file
content, dirstate recognizes a file as certainly clean, if:

  (1) it is already known as "normal",
  (2) dirstate entry for it has valid (= not "-1") timestamp, and
  (3) mode, size and timestamp of it on the filesystem are as same as
      ones expected in dirstate

This works as expected in many cases, but doesn't in the corner case
that changing a file keeps mode, size and timestamp of it on the
filesystem.

The timetable below shows steps in one of typical such situations:

  ---- ----------------------------------- ----------------
                                           timestamp of "f"
                                           ----------------
                                           dirstate   file-
  time          action                     mem  file  system
  ---- ----------------------------------- ---- ----- -----
   *                                             ***    ***
       - 'hg transplant REV1 REV2 ...'
         - transplanting REV1
           ....
   N
           - change "f", but keep size                   N
             (via 'patch.patch()')
           - 'dirstate.normal("f")'          N   ***
             (via 'repo.commit()')

         - transplanting REV2
           - change "f", but keep size                   N
             (via 'patch.patch()')
           - aborted while patching
  N+1
         - release wlock
           - 'dirstate.write()'              N    N      N

       - 'hg status' shows "r1" as "clean"   N    N      N
  ---- ----------------------------------- ---- ----- -----

The most important point is that 'dirstate.write()' is executed at N+1
or later. This causes writing dirstate timestamp N of "f" out
successfully. If it is executed at N, 'parsers.pack_dirstate()'
replaces timestamp N with "-1" before actual writing dirstate out.

This issue can occur when 'hg transplant' satisfies conditions below:

  - multiple revisions to be transplanted change the same file
  - those revisions don't change mode and size of the file, and
  - the 2nd or later revision of them fails after changing the file

The root cause of this issue is that files are changed without
flushing in-memory dirstate changes via 'repo.commit()' (even though
omitting 'dirstate.normallookup()' on files changed by 'patch.patch()'
for efficiency also causes this issue).

To detect changes of files correctly, this patch writes in-memory
dirstate changes out explicitly after marking files as clean in
'committablectx.markcommitted()', which is invoked via
'repo.commit()'.

After this change, timetable is changed as below:

  ---- ----------------------------------- ----------------
                                           timestamp of "f"
                                           ----------------
                                           dirstate   file-
  time          action                     mem  file  system
  ---- ----------------------------------- ---- ----- -----
   *                                             ***    ***
       - 'hg transplant REV1 REV2 ...'
         - transplanting REV1
           ....
   N
           - change "f", but keep size                   N
             (via 'patch.patch()')
           - 'dirstate.normal("f")'          N    ***
             (via 'repo.commit()')
       ----------------------------------- ---- ----- -----
           - 'dirsttate.write()'            -1    -1
       ----------------------------------- ---- ----- -----
         - transplanting REV2
           - change "f", but keep size                   N
             (via 'patch.patch()')
           - aborted while patching
  N+1
         - release wlock
           - 'dirstate.write()'              -1   -1     N

       - 'hg status' shows "r1" as "clean"   -1   -1     N
  ---- ----------------------------------- ---- ----- -----

To reproduce this issue in tests certainly, this patch emulates some
timing critical actions as below:

  - change "f" at N

    'patch.patch()' with 'fakepatchtime.py' explicitly changes mtime
    of patched files to "2000-01-01 00:00" (= N).

  - 'dirstate.write()' via 'repo.commit()' at N

    'fakedirstatewritetime.py' forces 'pack_dirstate()' to use
    "2000-01-01 00:00" as "now", only if 'pack_dirstate()' is invoked
    via 'committablectx.markcommitted()'.

  - 'dirstate.write()' via releasing wlock at N+1 (or "not at N")

    'pack_dirstate()' via releasing wlock uses actual timestamp at
    runtime as "now", and it should be different from the "2000-01-01
    00:00" of "f".

BTW, this patch doesn't test cases below, even though 'patch.patch()'
is used similarly in these cases:

  1. failure of 'hg import' or 'hg qpush'

  2. success of 'hg import', 'hg qpush' or 'hg transplant'

Case (1) above doesn't cause this kind of issue, because:

  - if patching is aborted by conflicts, changed files are committed

    changed files are marked as CLEAN, even though they are partially
    patched.

  - otherwise, dirstate are fully restored by 'dirstateguard'

    For example in timetable above, timestamp of "f" in .hg/dirstate
    is restored to -1 (or less than N), and subsequent 'hg status' can
    detect changes correctly.

Case (2) always causes 'repo.status()' invocation via 'repo.commit()'
just after changing files inside same wlock scope.

  ---- ----------------------------------- ----------------
                                           timestamp of "f"
                                           ----------------
                                           dirstate   file-
  time          action                     mem  file  system
  ---- ----------------------------------- ---- ----- -----
  N                                              ***   ***
       - make file "f" clean                            N

       - execute 'hg foobar'
         ....
         - 'dirstate.normal("f")'           N    ***
           (e.g. via dirty check
            or previous 'repo.commit()')

         - change "f", but keep size                    N
         - 'repo.status()' (*1)
           (via 'repo.commit()')
  ---- ----------------------------------- ---- ----- -----

At a glance, 'repo.status()' at (*1) seems to cause similar issue (=
"changed files are treated as clean"), but actually doesn't.

'dirstate._lastnormaltime' should be N at (*1) above, because
'dirstate.normal()' via dirty check is finished at N.

Therefore, "f" changed at N (= 'dirstate._lastnormaltime') is forcibly
treated as "unsure" at (*1), and changes are detected as expected (see
'dirstate.status()' for detail).

If 'hg import' is executed with '--no-commit', 'repo.status()' isn't
invoked just after changing files inside same wlock scope.

But preceding 'dirstate.normal()' is invoked inside another wlock
scope via 'cmdutil.bailifchanged()', and in-memory changes should be
flushed at the end of that scope.

Therefore, timestamp N of clean "f" should be replaced by -1, if
'dirstate.write()' is invoked at N. It means that condition of this
issue isn't satisfied.

  $ hg init

no bookmarks

  $ hg bookmarks
  no bookmarks set

  $ hg bookmarks -Tjson
  [
  ]

bookmark rev -1

  $ hg bookmark X

list bookmarks

  $ hg bookmarks
   * X                         -1:000000000000

list bookmarks with color

  $ hg --config extensions.color= --config color.mode=ansi \
  >    bookmarks --color=always
  \x1b[0;32m * \x1b[0m\x1b[0;32mX\x1b[0m\x1b[0;32m                         -1:000000000000\x1b[0m (esc)

  $ echo a > a
  $ hg add a
  $ hg commit -m 0

bookmark X moved to rev 0

  $ hg bookmarks
   * X                         0:f7b1eb17ad24

look up bookmark

  $ hg log -r X
  changeset:   0:f7b1eb17ad24
  bookmark:    X
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  

second bookmark for rev 0, command should work even with ui.strict on

  $ hg --config ui.strict=1 bookmark X2

bookmark rev -1 again

  $ hg bookmark -r null Y

list bookmarks

  $ hg bookmarks
     X                         0:f7b1eb17ad24
   * X2                        0:f7b1eb17ad24
     Y                         -1:000000000000

  $ echo b > b
  $ hg add b
  $ hg commit -m 1

  $ hg bookmarks -Tjson
  [
   {
    "active": false,
    "bookmark": "X",
    "node": "f7b1eb17ad24730a1651fccd46c43826d1bbc2ac",
    "rev": 0
   },
   {
    "active": true,
    "bookmark": "X2",
    "node": "925d80f479bb026b0fb3deb27503780b13f74123",
    "rev": 1
   },
   {
    "active": false,
    "bookmark": "Y",
    "node": "0000000000000000000000000000000000000000",
    "rev": -1
   }
  ]

bookmarks revset

  $ hg log -r 'bookmark()'
  changeset:   0:f7b1eb17ad24
  bookmark:    X
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  changeset:   1:925d80f479bb
  bookmark:    X2
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  
  $ hg log -r 'bookmark(Y)'
  $ hg log -r 'bookmark(X2)'
  changeset:   1:925d80f479bb
  bookmark:    X2
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  
  $ hg log -r 'bookmark("re:X")'
  changeset:   0:f7b1eb17ad24
  bookmark:    X
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  
  changeset:   1:925d80f479bb
  bookmark:    X2
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     1
  
  $ hg log -r 'bookmark("literal:X")'
  changeset:   0:f7b1eb17ad24
  bookmark:    X
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     0
  

  $ hg log -r 'bookmark(unknown)'
  abort: bookmark 'unknown' does not exist!
  [255]
  $ hg log -r 'bookmark("re:unknown")'
  abort: no bookmarks exist that match 'unknown'!
  [255]
  $ hg log -r 'present(bookmark("literal:unknown"))'
  $ hg log -r 'present(bookmark("re:unknown"))'

  $ hg help revsets | grep 'bookmark('
      "bookmark([name])"

bookmarks X and X2 moved to rev 1, Y at rev -1

  $ hg bookmarks
     X                         0:f7b1eb17ad24
   * X2                        1:925d80f479bb
     Y                         -1:000000000000

bookmark rev 0 again

  $ hg bookmark -r 0 Z

  $ hg update X
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (activating bookmark X)
  $ echo c > c
  $ hg add c
  $ hg commit -m 2
  created new head

bookmarks X moved to rev 2, Y at rev -1, Z at rev 0

  $ hg bookmarks
   * X                         2:db815d6d32e6
     X2                        1:925d80f479bb
     Y                         -1:000000000000
     Z                         0:f7b1eb17ad24

rename nonexistent bookmark

  $ hg bookmark -m A B
  abort: bookmark 'A' does not exist
  [255]

rename to existent bookmark

  $ hg bookmark -m X Y
  abort: bookmark 'Y' already exists (use -f to force)
  [255]

force rename to existent bookmark

  $ hg bookmark -f -m X Y

list bookmarks

  $ hg bookmark
     X2                        1:925d80f479bb
   * Y                         2:db815d6d32e6
     Z                         0:f7b1eb17ad24

bookmarks from a revset
  $ hg bookmark -r '.^1' REVSET
  $ hg bookmark -r ':tip' TIP
  $ hg up -q TIP
  $ hg bookmarks
     REVSET                    0:f7b1eb17ad24
   * TIP                       2:db815d6d32e6
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
     Z                         0:f7b1eb17ad24

  $ hg bookmark -d REVSET
  $ hg bookmark -d TIP

rename without new name or multiple names

  $ hg bookmark -m Y
  abort: new bookmark name required
  [255]
  $ hg bookmark -m Y Y2 Y3
  abort: only one new bookmark name allowed
  [255]

delete without name

  $ hg bookmark -d
  abort: bookmark name required
  [255]

delete nonexistent bookmark

  $ hg bookmark -d A
  abort: bookmark 'A' does not exist
  [255]

bookmark name with spaces should be stripped

  $ hg bookmark ' x  y '

list bookmarks

  $ hg bookmarks
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
     Z                         0:f7b1eb17ad24
   * x  y                      2:db815d6d32e6

look up stripped bookmark name

  $ hg log -r '"x  y"'
  changeset:   2:db815d6d32e6
  bookmark:    Y
  bookmark:    x  y
  tag:         tip
  parent:      0:f7b1eb17ad24
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     2
  

reject bookmark name with newline

  $ hg bookmark '
  > '
  abort: bookmark names cannot consist entirely of whitespace
  [255]

  $ hg bookmark -m Z '
  > '
  abort: bookmark names cannot consist entirely of whitespace
  [255]

bookmark with reserved name

  $ hg bookmark tip
  abort: the name 'tip' is reserved
  [255]

  $ hg bookmark .
  abort: the name '.' is reserved
  [255]

  $ hg bookmark null
  abort: the name 'null' is reserved
  [255]


bookmark with existing name

  $ hg bookmark X2
  abort: bookmark 'X2' already exists (use -f to force)
  [255]

  $ hg bookmark -m Y Z
  abort: bookmark 'Z' already exists (use -f to force)
  [255]

bookmark with name of branch

  $ hg bookmark default
  abort: a bookmark cannot have the name of an existing branch
  [255]

  $ hg bookmark -m Y default
  abort: a bookmark cannot have the name of an existing branch
  [255]

bookmark with integer name

  $ hg bookmark 10
  abort: cannot use an integer as a name
  [255]

incompatible options

  $ hg bookmark -m Y -d Z
  abort: --delete and --rename are incompatible
  [255]

  $ hg bookmark -r 1 -d Z
  abort: --rev is incompatible with --delete
  [255]

  $ hg bookmark -r 1 -m Z Y
  abort: --rev is incompatible with --rename
  [255]

force bookmark with existing name

  $ hg bookmark -f X2

force bookmark back to where it was, should deactivate it

  $ hg bookmark -fr1 X2
  $ hg bookmarks
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
     Z                         0:f7b1eb17ad24
     x  y                      2:db815d6d32e6

forward bookmark to descendant without --force

  $ hg bookmark Z
  moving bookmark 'Z' forward from f7b1eb17ad24

list bookmarks

  $ hg bookmark
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
   * Z                         2:db815d6d32e6
     x  y                      2:db815d6d32e6

revision but no bookmark name

  $ hg bookmark -r .
  abort: bookmark name required
  [255]

bookmark name with whitespace only

  $ hg bookmark ' '
  abort: bookmark names cannot consist entirely of whitespace
  [255]

  $ hg bookmark -m Y ' '
  abort: bookmark names cannot consist entirely of whitespace
  [255]

invalid bookmark

  $ hg bookmark 'foo:bar'
  abort: ':' cannot be used in a name
  [255]

  $ hg bookmark 'foo
  > bar'
  abort: '\n' cannot be used in a name
  [255]

the bookmark extension should be ignored now that it is part of core

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "bookmarks=" >> $HGRCPATH
  $ hg bookmarks
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
   * Z                         2:db815d6d32e6
     x  y                      2:db815d6d32e6

test summary

  $ hg summary
  parent: 2:db815d6d32e6 tip
   2
  branch: default
  bookmarks: *Z Y x  y
  commit: (clean)
  update: 1 new changesets, 2 branch heads (merge)
  phases: 3 draft

test id

  $ hg id
  db815d6d32e6 tip Y/Z/x  y

test rollback

  $ echo foo > f1
  $ hg bookmark tmp-rollback
  $ hg ci -Amr
  adding f1
  $ hg bookmarks
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
     Z                         2:db815d6d32e6
   * tmp-rollback              3:2bf5cfec5864
     x  y                      2:db815d6d32e6
  $ hg rollback
  repository tip rolled back to revision 2 (undo commit)
  working directory now based on revision 2
  $ hg bookmarks
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
     Z                         2:db815d6d32e6
   * tmp-rollback              2:db815d6d32e6
     x  y                      2:db815d6d32e6
  $ hg bookmark -f Z -r 1
  $ hg rollback
  repository tip rolled back to revision 2 (undo bookmark)
  $ hg bookmarks
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
     Z                         2:db815d6d32e6
   * tmp-rollback              2:db815d6d32e6
     x  y                      2:db815d6d32e6
  $ hg bookmark -d tmp-rollback

activate bookmark on working dir parent without --force

  $ hg bookmark --inactive Z
  $ hg bookmark Z

test clone

  $ hg bookmark -r 2 -i @
  $ hg bookmark -r 2 -i a@
  $ hg bookmarks
     @                         2:db815d6d32e6
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
   * Z                         2:db815d6d32e6
     a@                        2:db815d6d32e6
     x  y                      2:db815d6d32e6
  $ hg clone . cloned-bookmarks
  updating to bookmark @
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R cloned-bookmarks bookmarks
   * @                         2:db815d6d32e6
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
     Z                         2:db815d6d32e6
     a@                        2:db815d6d32e6
     x  y                      2:db815d6d32e6

test clone with pull protocol

  $ hg clone --pull . cloned-bookmarks-pull
  requesting all changes
  adding changesets
  adding manifests
  adding file changes
  added 3 changesets with 3 changes to 3 files (+1 heads)
  updating to bookmark @
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R cloned-bookmarks-pull bookmarks
   * @                         2:db815d6d32e6
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
     Z                         2:db815d6d32e6
     a@                        2:db815d6d32e6
     x  y                      2:db815d6d32e6

delete multiple bookmarks at once

  $ hg bookmark -d @ a@

test clone with a bookmark named "default" (issue3677)

  $ hg bookmark -r 1 -f -i default
  $ hg clone . cloned-bookmark-default
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R cloned-bookmark-default bookmarks
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
     Z                         2:db815d6d32e6
     default                   1:925d80f479bb
     x  y                      2:db815d6d32e6
  $ hg -R cloned-bookmark-default parents -q
  2:db815d6d32e6
  $ hg bookmark -d default

test clone with a specific revision

  $ hg clone -r 925d80 . cloned-bookmarks-rev
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R cloned-bookmarks-rev bookmarks
     X2                        1:925d80f479bb

test clone with update to a bookmark

  $ hg clone -u Z . cloned-bookmarks-update
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ hg -R cloned-bookmarks-update bookmarks
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
   * Z                         2:db815d6d32e6
     x  y                      2:db815d6d32e6

create bundle with two heads

  $ hg clone . tobundle
  updating to branch default
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ echo x > tobundle/x
  $ hg -R tobundle add tobundle/x
  $ hg -R tobundle commit -m'x'
  $ hg -R tobundle update -r -2
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo y > tobundle/y
  $ hg -R tobundle branch test
  marked working directory as branch test
  (branches are permanent and global, did you want a bookmark?)
  $ hg -R tobundle add tobundle/y
  $ hg -R tobundle commit -m'y'
  $ hg -R tobundle bundle tobundle.hg
  searching for changes
  2 changesets found
  $ hg unbundle tobundle.hg
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)
  (run 'hg heads' to see heads, 'hg merge' to merge)

update to active bookmark if it's not the parent

  $ hg summary
  parent: 2:db815d6d32e6 
   2
  branch: default
  bookmarks: *Z Y x  y
  commit: 1 added, 1 unknown (new branch head)
  update: 2 new changesets (update)
  phases: 5 draft
  $ hg update
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  updating bookmark Z
  $ hg bookmarks
     X2                        1:925d80f479bb
     Y                         2:db815d6d32e6
   * Z                         3:125c9a1d6df6
     x  y                      2:db815d6d32e6

pull --update works the same as pull && update

  $ hg bookmark -r3 Y
  moving bookmark 'Y' forward from db815d6d32e6
  $ hg -R cloned-bookmarks-update update Y
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (activating bookmark Y)
  $ hg -R cloned-bookmarks-update pull --update .
  pulling from .
  searching for changes
  adding changesets
  adding manifests
  adding file changes
  added 2 changesets with 2 changes to 2 files (+1 heads)
  updating bookmark Y
  updating bookmark Z
  updating to active bookmark Y
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

test wrongly formated bookmark

  $ echo '' >> .hg/bookmarks
  $ hg bookmarks
     X2                        1:925d80f479bb
     Y                         3:125c9a1d6df6
   * Z                         3:125c9a1d6df6
     x  y                      2:db815d6d32e6
  $ echo "Ican'thasformatedlines" >> .hg/bookmarks
  $ hg bookmarks
  malformed line in .hg/bookmarks: "Ican'thasformatedlines"
     X2                        1:925d80f479bb
     Y                         3:125c9a1d6df6
   * Z                         3:125c9a1d6df6
     x  y                      2:db815d6d32e6

test missing revisions

  $ echo "925d80f479bc z" > .hg/bookmarks
  $ hg book
  no bookmarks set

test stripping a non-checked-out but bookmarked revision

  $ hg log --graph
  o  changeset:   4:9ba5f110a0b3
  |  branch:      test
  |  tag:         tip
  |  parent:      2:db815d6d32e6
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     y
  |
  | @  changeset:   3:125c9a1d6df6
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     x
  |
  o  changeset:   2:db815d6d32e6
  |  parent:      0:f7b1eb17ad24
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     2
  |
  | o  changeset:   1:925d80f479bb
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     1
  |
  o  changeset:   0:f7b1eb17ad24
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     0
  
  $ hg book should-end-on-two
  $ hg co --clean 4
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (leaving bookmark should-end-on-two)
  $ hg book four
  $ hg --config extensions.mq= strip 3
  saved backup bundle to * (glob)
should-end-on-two should end up pointing to revision 2, as that's the
tipmost surviving ancestor of the stripped revision.
  $ hg log --graph
  @  changeset:   3:9ba5f110a0b3
  |  branch:      test
  |  bookmark:    four
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     y
  |
  o  changeset:   2:db815d6d32e6
  |  bookmark:    should-end-on-two
  |  parent:      0:f7b1eb17ad24
  |  user:        test
  |  date:        Thu Jan 01 00:00:00 1970 +0000
  |  summary:     2
  |
  | o  changeset:   1:925d80f479bb
  |/   user:        test
  |    date:        Thu Jan 01 00:00:00 1970 +0000
  |    summary:     1
  |
  o  changeset:   0:f7b1eb17ad24
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     0
  

test clearing divergent bookmarks of linear ancestors

  $ hg bookmark Z -r 0
  $ hg bookmark Z@1 -r 1
  $ hg bookmark Z@2 -r 2
  $ hg bookmark Z@3 -r 3
  $ hg book
     Z                         0:f7b1eb17ad24
     Z@1                       1:925d80f479bb
     Z@2                       2:db815d6d32e6
     Z@3                       3:9ba5f110a0b3
   * four                      3:9ba5f110a0b3
     should-end-on-two         2:db815d6d32e6
  $ hg bookmark Z
  moving bookmark 'Z' forward from f7b1eb17ad24
  $ hg book
   * Z                         3:9ba5f110a0b3
     Z@1                       1:925d80f479bb
     four                      3:9ba5f110a0b3
     should-end-on-two         2:db815d6d32e6

test clearing only a single divergent bookmark across branches

  $ hg book foo -r 1
  $ hg book foo@1 -r 0
  $ hg book foo@2 -r 2
  $ hg book foo@3 -r 3
  $ hg book foo -r foo@3
  $ hg book
   * Z                         3:9ba5f110a0b3
     Z@1                       1:925d80f479bb
     foo                       3:9ba5f110a0b3
     foo@1                     0:f7b1eb17ad24
     foo@2                     2:db815d6d32e6
     four                      3:9ba5f110a0b3
     should-end-on-two         2:db815d6d32e6