$ glog() {

  >   hg glog --template '{rev}@{branch}({phase}) {desc|firstline}\n' "$@"

  > }

  $ glog

  @  2@foo(draft) adda

Test no-op

  $ hg amend

  abort: no updates found

  [255]

  $ glog

  @  2@foo(draft) adda

Test forcing the message to the same value, no intermediate revision.

  $ hg amend -m 'adda'

  abort: no updates found

  [255]

  $ glog

  @  2@foo(draft) adda

Test collapsing into an existing revision, no intermediate revision.

  $ echo a >> a

  $ hg ci -m changea

  $ echo a > a

  $ hg ci -m reseta

  $ hg amend --change 2

  abort: no updates found

  [255]

  $ hg phase 2

  2: draft

  $ glog

  @  4@foo(draft) reseta

  |

  o  3@foo(draft) changea

  |

  o  2@foo(draft) adda

Test collapsing into an existing rev, with an intermediate revision.

  $ hg branch --force default

  marked working directory as branch default

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

  $ hg ci -m resetbranch

  created new head

  $ hg branch --force foo

  marked working directory as branch foo

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

  $ hg amend --change 2

  abort: no updates found

  [255]

  $ glog

  @  6@foo(secret) amends a34b93d251e49c93d5685ebacad785c73a7e8605

  |

  o  5@default(draft) resetbranch

  |

  o  4@foo(draft) reseta

  |

  o  3@foo(draft) changea

  |

  o  2@foo(draft) adda