$ heads()

  > {

  >    hg heads --template '{rev}: {desc|firstline|strip} ({branches})\n' "$@"

  > }

  $ hg init a

  $ cd a

  $ echo 'root' >root

  $ hg add root

  $ hg commit -m "Adding root node"

  $ heads

  0: Adding root node ()

-------

  $ heads .

  0: 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 -m "Adding a branch"

  $ heads

  1: Adding a branch (a)

  0: Adding root node ()

-------

  $ heads .

  1: Adding a branch (a)

=======

  $ 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

  (branches are permanent and global, did you want a bookmark?)

  $ hg commit -m "Adding b branch"

  $ heads

  2: Adding b branch (b)

  1: Adding a branch (a)

  0: Adding root node ()

-------

  $ heads .

  2: Adding b branch (b)

=======

  $ echo 'bh1' >bh1

  $ hg add bh1

  $ hg commit -m "Adding b branch head 1"

  $ heads

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

-------

  $ heads .

  3: Adding b branch head 1 (b)

=======

  $ hg update -C 2

  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo 'bh2' >bh2

  $ hg add bh2

  $ hg commit -m "Adding b branch head 2"

  created new head

  $ heads

  4: Adding b branch head 2 (b)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

  $ heads .

  4: Adding b branch head 2 (b)

  3: Adding b branch head 1 (b)

=======

  $ hg update -C 2

  0 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo 'bh3' >bh3

  $ hg add bh3

  $ hg commit -m "Adding b branch head 3"

  created new head

  $ heads

  5: Adding b branch head 3 (b)

  4: Adding b branch head 2 (b)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

-------

  $ heads .

  5: Adding b branch head 3 (b)

  4: Adding b branch head 2 (b)

  3: Adding b branch head 1 (b)

=======

  $ hg merge 4

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  (branch merge, don't forget to commit)

  $ hg commit -m "Merging b branch head 2 and b branch head 3"

  $ heads

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

-------

  $ heads .

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

=======

  $ echo 'c' >c

  $ hg add c

  $ hg branch c

  marked working directory as branch c

  (branches are permanent and global, did you want a bookmark?)

  $ hg commit -m "Adding c branch"

  $ heads

  7: Adding c branch (c)

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

-------

  $ heads .

  7: Adding c branch (c)

=======

  $ heads -r 3 .

  no open branch heads found on branches c (started at 3)

  [1]

  $ heads -r 2 .

  7: Adding c branch (c)

-------

  $ hg update -C 4

  0 files updated, 0 files merged, 2 files removed, 0 files unresolved

-------

  $ heads -r 3 .

  3: Adding b branch head 1 (b)

-------

  $ heads -r 2 .

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

-------

  $ heads -r 7 .

  no open branch heads found on branches b (started at 7)

  [1]

=======

  $ for i in 0 1 2 3 4 5 6 7; do

  >     hg update -C "$i"

  >     heads

  >     echo '-------'

  >     heads .

  >     echo '-------'

  > done

  0 files updated, 0 files merged, 2 files removed, 0 files unresolved

  7: Adding c branch (c)

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

  -------

  0: Adding root node ()

  -------

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  7: Adding c branch (c)

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

  -------

  1: Adding a branch (a)

  -------

  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  7: Adding c branch (c)

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

  -------

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  -------

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  7: Adding c branch (c)

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

  -------

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  -------

  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  7: Adding c branch (c)

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

  -------

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  -------

  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  7: Adding c branch (c)

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

  -------

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  -------

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  7: Adding c branch (c)

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

  -------

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  -------

  1 files updated, 0 files merged, 0 files removed, 0 files unresolved

  7: Adding c branch (c)

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

  -------

  7: Adding c branch (c)

  -------

=======

  $ for i in a b c z; do

  >     heads "$i"

  >     echo '-------'

  > done

  1: Adding a branch (a)

  -------

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  -------

  7: Adding c branch (c)

  -------

  abort: unknown revision 'z'!

  -------

=======

  $ heads 0 1 2 3 4 5 6 7

  7: Adding c branch (c)

  6: Merging b branch head 2 and b branch head 3 (b)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  0: Adding root node ()

Topological heads:

  $ heads -t

  7: Adding c branch (c)

  3: Adding b branch head 1 (b)

  1: Adding a branch (a)

  $ cd ..

______________

"created new head" message tests

  $ hg init newheadmsg

  $ cd newheadmsg

Init: no msg

  $ echo 1 > a

  $ hg ci -Am "a0: Initial root"

  adding a

  $ echo 2 >> a

  $ hg ci -m "a1 (HN)"

  $ hg branch b

  marked working directory as branch b

  (branches are permanent and global, did you want a bookmark?)

  $ echo 1 > b

  $ hg ci -Am "b2: Initial root for branch b"

  adding b

  $ echo 2 >> b

  $ hg ci -m "b3 (HN)"

Case NN: msg

  $ hg up -q null

  $ hg branch -f b

  marked working directory as branch b

  (branches are permanent and global, did you want a bookmark?)

  $ echo 1 > bb

  $ hg ci -Am "b4 (NN): new topo root for branch b"

  adding bb

  created new head

Case HN: no msg

  $ echo 2 >> bb

  $ hg ci -m "b5 (HN)"

Case BN: msg

  $ hg branch -f default

  marked working directory as branch default

  (branches are permanent and global, did you want a bookmark?)

  $ echo 1 > aa

  $ hg ci -Am "a6 (BN): new branch root"

  adding aa

  created new head

Case CN: msg

  $ hg up -q 4

  $ echo 3 >> bbb

  $ hg ci -Am "b7 (CN): regular new head"

  adding bbb

  created new head

Case BB: msg

  $ hg up -q 4

  $ hg merge -q 3

  $ hg branch -f default

  marked working directory as branch default

  (branches are permanent and global, did you want a bookmark?)

  $ hg ci -m "a8 (BB): weird new branch root"

  created new head

Case CB: msg

  $ hg up -q 4

  $ hg merge -q 1

  $ hg ci -m "b9 (CB): new head from branch merge"

  created new head

Case HB: no msg

  $ hg up -q 7

  $ hg merge -q 6

  $ hg ci -m "b10 (HB): continuing head from branch merge"

Case CC: msg

  $ hg up -q 4

  $ hg merge -q 2

  $ hg ci -m "b11 (CC): new head from merge"

  created new head

Case CH: no msg

  $ hg up -q 2

  $ hg merge -q 10

  $ hg ci -m "b12 (CH): continuing head from merge"

Case HH: no msg

  $ hg merge -q 3

  $ hg ci -m "b12 (HH): merging two heads"