$ . "$TESTDIR/testlib/topic_setup.sh"

  $ hg init pinky

  $ cd pinky

  $ cat <<EOF >> .hg/hgrc

  > [phases]

  > publish=false

  > EOF

  $ cat <<EOF >> $HGRCPATH

  > [experimental]

  > # disable the new graph style until we drop 3.7 support

  > graphstyle.missing = |

  > EOF

  $ hg help -e topic

  topic extension - support for topic branches

  Topic branches are lightweight branches which disappear when changes are

  finalized (move to the public phase).

  Compared to bookmark, topic is reference carried by each changesets of the

  series instead of just the single head revision.  Topic are quite similar to

  the way named branch work, except they eventually fade away when the changeset

  becomes part of the immutable history. Changeset can belong to both a topic

  and a named branch, but as long as it is mutable, its topic identity will

  prevail. As a result, default destination for 'update', 'merge', etc...  will

  take topic into account. When a topic is active these operations will only

  consider other changesets on that topic (and, in some occurrence, bare

  changeset on same branch).  When no topic is active, changeset with topic will

  be ignored and only bare one on the same branch will be taken in account.

  There is currently two commands to be used with that extension: 'topics' and

  'stack'.

  The 'hg topics' command is used to set the current topic, change and list

  existing one. 'hg topics --verbose' will list various information related to

  each topic.

  The 'stack' will show you information about the stack of commit belonging to

  your current topic.

  Topic is offering you aliases reference to changeset in your current topic

  stack as 's#'. For example, 's1' refers to the root of your stack, 's2' to the

  second commits, etc. The 'hg stack' command show these number. 's0' can be

  used to refer to the parent of the topic root. Updating using 'hg up s0' will

  keep the topic active.

  Push behavior will change a bit with topic. When pushing to a publishing

  repository the changesets will turn public and the topic data on them will

  fade away. The logic regarding pushing new heads will behave has before,

  ignore any topic related data. When pushing to a non-publishing repository

  (supporting topic), the head checking will be done taking topic data into

  account. Push will complain about multiple heads on a branch if you push

  multiple heads with no topic information on them (or multiple public heads).

  But pushing a new topic will not requires any specific flag. However, pushing

  multiple heads on a topic will be met with the usual warning.

  The 'evolve' extension takes 'topic' into account. 'hg evolve --all' will

  evolve all changesets in the active topic. In addition, by default. 'hg next'

  and 'hg prev' will stick to the current topic.

  Be aware that this extension is still an experiment, commands and other

  features are likely to be change/adjusted/dropped over time as we refine the

  concept.

  topic-mode

  ==========

  The topic extension can be configured to ensure the user do not forget to add

  a topic when committing a new topic:

    [experimental]

    # behavior when commit is made without an active topic

    topic-mode = ignore # do nothing special (default)

    topic-mode = warning # print a warning

    topic-mode = enforce # abort the commit (except for merge)

    topic-mode = enforce-all # abort the commit (even for merge)

    topic-mode = random # use a randomized generated topic (except for merge)

    topic-mode = random-all # use a randomized generated topic (even for merge)

  Single head enforcing

  =====================

  The extensions come with an option to enforce that there is only one heads for

  each name in the repository at any time.

    [experimental]

    enforce-single-head = yes

  Publishing behavior

  ===================

  Topic vanish when changeset move to the public phases. Moving to the public

  phase usually happens on push, but it is possible to update that behavior. The

  server needs to have specific config for this.

  * everything pushed become public (the default):

      [phase]

      publish = yes

  * nothing push turned public:

      [phase]

      publish = no

  * topic branches are not published, changeset without topic are:

      [phase]

      publish = no

      [experimental]

      topic.publish-bare-branch = yes

  In addition, the topic extension adds a "--publish" flag on 'hg push'. When

  used, the pushed revisions are published if the push succeeds. It also applies

  to common revisions selected by the push.

  One can prevent any publishing to happens in a repository using:

    [experimental]

    topic.allow-publish = no

  Server side visibility

  ======================

  Serving changesets with topics to clients without topic extension can get

  confusing. Such clients will have multiple anonymous heads without a clear way

  to distinguish them. They will also "lose" the canonical heads of the branch.

  To avoid this confusion, server can be configured to only serve changesets

  with topics to clients with the topic extension (version 9.3+). This might

  become the default in future:

    [experimental]

    topic.server-gate-topic-changesets = yes

  list of commands:

  Change organization:

   topics        View current topic, set current topic, change topic for a set

                 of revisions, or see all topics.

  Change navigation:

   stack         list all changesets in a topic and other information

  (use 'hg help -v topic' to show built-in aliases and global options)

  $ hg help topics

  hg topics [OPTION]... [-r REV]... [TOPIC]

  View current topic, set current topic, change topic for a set of revisions, or

  see all topics.

      Clear topic on existing topiced revisions:

        hg topics --rev <related revset> --clear

      Change topic on some revisions:

        hg topics <newtopicname> --rev <related revset>

      Clear current topic:

        hg topics --clear

      Set current topic:

        hg topics <topicname>

      List of topics:

        hg topics

      List of topics sorted according to their last touched time displaying last

      touched time and the user who last touched the topic:

        hg topics --age

      The active topic (if any) will be prepended with a "*".

      The '--current' flag helps to take active topic into account. For example,

      if you want to set the topic on all the draft changesets to the active

      topic, you can do: 'hg topics -r "draft()" --current'

      The --verbose version of this command display various information on the

      state of each topic.

  options ([+] can be repeated):

      --clear             clear active topic if any

   -r --rev REV [+]       revset of existing revisions

   -l --list              show the stack of changeset in the topic

      --age               show when you last touched the topics

      --current           display the current topic only

   -T --template TEMPLATE display with template

  (some details hidden, use --verbose to show complete help)

  $ hg topics

Test topics interaction with evolution:

  $ hg topics --config experimental.evolution=

  $ hg topics --config experimental.evolution= --rev . bob

  abort: must have obsolete enabled to change topics

  [255]

Create some changes:

  $ for x in alpha beta gamma delta ; do

  >   echo file $x >> $x

  >   hg addremove

  >   hg ci -m "Add file $x"

  > done

  adding alpha

  adding beta

  adding gamma

  adding delta

Still no topics

  $ hg topics

  $ hg topics --current

  no active topic

  [1]

  $ hg topics --current somerandomtopic

  abort: cannot use --current when setting a topic

  [255]

  $ hg topics --current --clear

  abort: cannot use --current and --clear

  [255]

  $ hg topics --clear somerandomtopic

  abort: cannot use --clear when setting a topic

  [255]

Trying some invalid topicnames

  $ hg topic '.'

  abort: the name '.' is reserved

  [255]

  $ hg topic null

  abort: the name 'null' is reserved

  [255]

  $ hg topic tip

  abort: the name 'tip' is reserved

  [255]

  $ hg topic 12345

  abort: cannot use an integer as a name

  [255]

  $ hg topic '   '

  abort: topic name cannot consist entirely of whitespaces

  [255]

  $ hg topic 'a12#45'

  abort: invalid topic name: 'a12#45'

  (topic names can only consist of alphanumeric, '-' '_' and '.' characters)

  [255]

  $ hg topic 'foo bar'

  abort: invalid topic name: 'foo bar'

  (topic names can only consist of alphanumeric, '-' '_' and '.' characters)

  [255]

this is trying to list topic names

  $ hg topic ''

  $ hg topic '*12 B23'

  abort: invalid topic name: '*12 B23'

  (topic names can only consist of alphanumeric, '-' '_' and '.' characters)

  [255]

Test commit flag and help text

  $ echo stuff >> alpha

  $ HGEDITOR=cat hg ci -t topicflag

  HG: Enter commit message.  Lines beginning with 'HG:' are removed.

  HG: Leave message empty to abort commit.

  HG: --

  HG: user: test

  HG: topic 'topicflag'

  HG: branch 'default'

  HG: changed alpha

  abort: empty commit message

  [255]

  $ hg revert alpha

  $ hg topic

   * topicflag (0 changesets)

Make a topic

  $ hg topic narf

  $ hg topics

   * narf (0 changesets)

  $ hg topics -v

   * narf (on branch: default, 0 changesets)

  $ hg stack

  ### topic: narf

  ### target: default (branch)

  (stack is empty)

  s0^ Add file delta (base current)

Add commits to topic

  $ echo topic work >> alpha

  $ hg ci -m 'start on narf'

  active topic 'narf' grew its first changeset

  (see 'hg help topics' for more information)

  $ hg co .^

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

  $ hg topic fran

  marked working directory as topic: fran

  $ hg topics

   * fran (0 changesets)

     narf (1 changesets)

  $ hg topics --current

  fran

  $ echo >> fran work >> beta

  $ hg ci -m 'start on fran'

  active topic 'fran' grew its first changeset

  (see 'hg help topics' for more information)

  $ hg co narf

  switching to topic narf

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

  $ hg topic

     fran (1 changesets)

   * narf (1 changesets)

  $ hg log -r . -T '{topics}\n'

  narf

  $ echo 'narf!!!' >> alpha

  $ hg ci -m 'narf!'

  $ hg log -G

  @  changeset:   6:7c34953036d6

  |  tag:         tip

  |  topic:       narf

  |  parent:      4:fb147b0b417c

  |  user:        test

  |  date:        Thu Jan 01 00:00:00 1970 +0000

  |  summary:     narf!

  |

  | o  changeset:   5:0469d521db49

  | |  topic:       fran

  | |  parent:      3:a53952faf762

  | |  user:        test

  | |  date:        Thu Jan 01 00:00:00 1970 +0000

  | |  summary:     start on fran

  | |

  o |  changeset:   4:fb147b0b417c

  |/   topic:       narf

  |    user:        test

  |    date:        Thu Jan 01 00:00:00 1970 +0000

  |    summary:     start on narf

  |

  o  changeset:   3:a53952faf762

  |  user:        test

  |  date:        Thu Jan 01 00:00:00 1970 +0000

  |  summary:     Add file delta

  |

  o  changeset:   2:15d1eb11d2fa

  |  user:        test

  |  date:        Thu Jan 01 00:00:00 1970 +0000