1 =========================================
2 TopGit -- A different patch queue manager
3 =========================================
9 TopGit aims to make handling of large amounts of interdependent topic
10 branches easier. In fact, it is designed especially for the case where
11 you maintain a queue of third-party patches on top of another (perhaps
12 Git-controlled) project and want to easily organize, maintain and submit
13 them -- TopGit achieves that by keeping a separate topic branch for each
14 patch and providing some tools to maintain the branches.
20 See the file ``INSTALL``.
26 The TopGit git repository can be found at <http://repo.or.cz/topgit/pro>.
32 Why not use something like StGIT or Guilt or ``rebase -i`` for maintaining
33 your patch queue? The advantage of these tools is their simplicity;
34 they work with patch *series* and defer to the reflog facility for
35 version control of patches (reordering of patches is not
36 version-controlled at all). But there are several disadvantages -- for
37 one, these tools (especially StGIT) do not actually fit well with plain
38 Git at all: it is basically impossible to take advantage of the index
39 effectively when using StGIT. But more importantly, these tools
40 horribly fail in the face of a distributed environment.
42 TopGit has been designed around three main tenets:
44 (i) TopGit is as thin a layer on top of Git as possible. You
45 still maintain your index and commit using Git; TopGit will only
46 automate a few indispensable tasks.
48 (ii) TopGit is anxious about *keeping* your history. It will
49 never rewrite your history, and all metadata is also tracked
50 by Git, smoothly and non-obnoxiously. It is good to have a
51 *single* point when the history is cleaned up, and that is at
52 the point of inclusion in the upstream project; locally, you
53 can see how your patch has evolved and easily return to older
56 (iii) TopGit is specifically designed to work in a
57 distributed environment. You can have several instances of
58 TopGit-aware repositories and smoothly keep them all
59 up-to-date and transfer your changes between them.
61 As mentioned above, the main intended use-case for TopGit is tracking
62 third-party patches, where each patch is effectively a single topic
63 branch. In order to flexibly accommodate even complex scenarios when
64 you track many patches where many are independent but some depend on
65 others, TopGit ignores the ancient Quilt heritage of patch series and
66 instead allows the patches to freely form graphs (DAGs just like Git
67 history itself, only "one level higher"). For now, you have to manually
68 specify which patches the current one depends on, but TopGit might help
69 you with that in the future in a darcs-like fashion.
71 A glossary plug: The union (i.e. merge) of patch dependencies is called
72 a *base* of the patch (topic branch).
74 Of course, TopGit is perhaps not the right tool for you:
76 (i) TopGit is not complicated, but StGIT et al. are somewhat
77 simpler, conceptually. If you just want to make a linear
78 purely-local patch queue, deferring to StGIT instead might
81 (ii) When using TopGit, your history can get a little hairy
82 over time, especially with all the merges rippling through.
91 ## Create and evolve a topic branch
92 $ tg create t/gitweb/pathinfo-action
93 tg: Automatically marking dependency on master
94 tg: Creating t/gitweb/pathinfo-action base from master...
100 ## Create another topic branch on top of the former one
101 $ tg create t/gitweb/nifty-links
102 tg: Automatically marking dependency on t/gitweb/pathinfo-action
103 tg: Creating t/gitweb/nifty-links base from t/gitweb/pathinfo-action...
107 ## Create another topic branch on top of master and submit
108 ## the resulting patch upstream
109 $ tg create t/revlist/author-fixed master
110 tg: Creating t/revlist/author-fixed base from master...
114 tg: Sent t/revlist/author-fixed
116 To: git@vger.kernel.org
117 Cc: gitster@pobox.com
118 Subject: [PATCH] Fix broken revlist --author when --fixed-string
120 ## Create another topic branch depending on two others non-trivially
121 $ tg create t/whatever t/revlist/author-fixed t/gitweb/nifty-links
122 tg: Creating t/whatever base from t/revlist/author-fixed...
123 tg: Merging t/whatever base with t/gitweb/nifty-links...
125 tg: Please commit merge resolution and call: tg create
126 tg: It is also safe to abort this operation using `git reset --hard`
127 tg: but please remember you are on the base branch now;
128 tg: you will want to switch to a different branch.
132 tg: Resuming t/whatever setup...
136 ## Update a single topic branch and propagate the changes to
138 $ git checkout t/gitweb/nifty-links
141 $ git checkout t/whatever
143 Topic Branch: t/whatever (1 commit)
144 Subject: [PATCH] Whatever patch
146 Depends: t/revlist/author-fixed t/gitweb/nifty-links
148 t/gitweb/nifty-links (1 commit)
150 tg: Updating base with t/gitweb/nifty-links changes...
152 tg: Please commit merge resolution and call `tg update` again.
153 tg: It is also safe to abort this operation using `git reset --hard`,
154 tg: but please remember you are on the base branch now;
155 tg: you will want to switch to a different branch.
159 tg: Updating t/whatever against new base...
161 tg: Please resolve the merge and commit. No need to do anything else.
162 tg: You can abort this operation using `git reset --hard` now
163 tg: and retry this merge later using `tg update`.
167 ## Update a single topic branch and propagate the changes
168 ## further through the dependency chain
169 $ git checkout t/gitweb/pathinfo-action
172 $ git checkout t/whatever
174 Topic Branch: t/whatever (1/2 commits)
175 Subject: [PATCH] Whatever patch
177 Depends: t/revlist/author-fixed t/gitweb/nifty-links
179 t/gitweb/pathinfo-action (<= t/gitweb/nifty-links) (1 commit)
181 tg: Recursing to t/gitweb/nifty-links...
182 [t/gitweb/nifty-links] tg: Updating base with t/gitweb/pathinfo-action changes...
184 [t/gitweb/nifty-links] tg: Please commit merge resolution and call `tg update` again.
185 [t/gitweb/nifty-links] tg: It is also safe to abort this operation using `git reset --hard`,
186 [t/gitweb/nifty-links] tg: but please remember you are on the base branch now;
187 [t/gitweb/nifty-links] tg: you will want to switch to a different branch.
188 [t/gitweb/nifty-links] tg: You are in a subshell. If you abort the merge,
189 [t/gitweb/nifty-links] tg: use `exit` to abort the recursive update altogether.
190 [t/gitweb/nifty-links] $ ..resolve..
191 [t/gitweb/nifty-links] $ git commit
192 [t/gitweb/nifty-links] $ tg update
193 [t/gitweb/nifty-links] tg: Updating t/gitweb/nifty-links against new base...
195 [t/gitweb/nifty-links] tg: Please resolve the merge and commit.
196 [t/gitweb/nifty-links] tg: You can abort this operation using `git reset --hard`.
197 [t/gitweb/nifty-links] tg: You are in a subshell. After you either commit or abort
198 [t/gitweb/nifty-links] tg: your merge, use `exit` to proceed with the recursive update.
199 [t/gitweb/nifty-links] $ ..resolve..
200 [t/gitweb/nifty-links] $ git commit
201 [t/gitweb/nifty-links] $ exit
202 tg: Updating base with t/gitweb/nifty-links changes...
203 tg: Updating t/whatever against new base...
205 ## Clone a TopGit-controlled repository
208 $ tg remote --populate origin
213 ## Add a TopGit remote to a repository and push to it
214 $ git remote add foo URL
218 ## Update from a non-default TopGit remote
227 The ``tg`` tool has several subcommands:
231 Our sophisticated integrated help facility. Mostly duplicates
236 # to get help for a particular command:
238 # to get help for a particular command in a browser window:
239 $ tg help -w <command>
240 # to get help on TopGit itself
242 # to get help on TopGit itself in a browser
247 Create a new TopGit-controlled topic branch of the given name
248 (required argument) and switch to it. If no dependencies are
249 specified (by extra arguments passed after the first one), the
250 current branch is assumed to be the only dependency.
252 After ``tg create``, you should insert the patch description into
253 the ``.topmsg`` file, which will already contain some prefilled
254 bits. You can set the ``topgit.to``, ``topgit.cc`` and ``topgit.bcc``
255 git configuration variables (see ``man git-config``) in order to
256 have ``tg create`` add these headers with the given default values
259 The main task of ``tg create`` is to set up the topic branch base
260 from the dependencies. This may fail due to merge conflicts.
261 In that case, after you commit the conflict resolution, you
262 should call ``tg create`` again (without any arguments); it will
263 detect that you are on a topic branch base ref and resume the
264 topic branch creation operation.
266 In an alternative use case, if ``-r BRANCH`` is given instead of a
267 dependency list, the topic branch is created based on the given
272 Remove a TopGit-controlled topic branch of the given name
273 (required argument). Normally, this command will remove only an
274 empty branch (base == head) without dependendents; use ``-f`` to
275 remove a non-empty branch or a branch that is depended upon by
278 The ``-f`` option is also useful to force removal of a branch's
279 base, if you used ``git branch -D B`` to remove branch B, and then
280 certain TopGit commands complain, because the base of branch B
283 IMPORTANT: Currently, this command will *NOT* remove the branch
284 from the dependency list in other branches. You need to take
285 care of this *manually*. This is even more complicated in
286 combination with ``-f`` -- in that case, you need to manually
287 unmerge the removed branch's changes from the branches depending
290 See also ``tg annihilate``.
292 | TODO: ``-a`` to delete all empty branches, depfix, revert
296 Make a commit on the current TopGit-controlled topic branch
297 that makes it equal to its base, including the presence or
298 absence of .topmsg and .topdeps. Annihilated branches are not
299 displayed by ``tg summary``, so they effectively get out of your
300 way. However, the branch still exists, and ``tg push`` will
301 push it (except if given the ``-a`` option). This way, you can
302 communicate that the branch is no longer wanted.
304 When annihilating a branch that has dependents (i.e. branches
305 that depend on it), those dependents have the dependencies of
306 the branch being annihilated added to them if they do not already
307 have them as dependencies. Essentially the DAG is repaired to
308 skip over the annihilated branch.
310 Normally, this command will remove only an empty branch
311 (base == head, except for changes to the .top* files); use
312 ``-f`` to annihilate a non-empty branch.
316 Change the dependencies of a TopGit-controlled topic branch.
317 This should have several subcommands, but only ``add`` is
320 The ``add`` subcommand takes an argument naming a topic branch to
321 be added, adds it to ``.topdeps``, performs a commit and then
322 updates your topic branch accordingly. If you want to do other
323 things related to the dependency addition, like adjusting
324 ``.topmsg``, prepare them in the index before calling ``tg depend
327 | TODO: Subcommand for removing dependencies, obviously
331 List files changed by the current or specified topic branch.
334 -i list files based on index instead of branch
335 -w list files based on working tree instead of branch
339 Show summary information about the current or specified topic
342 Numbers in parenthesis after a branch name such as "(11/3 commits)"
343 indicate how many commits on the branch (11) and how many of those
344 are non-merge commits (3).
348 Generate a patch from the current or specified topic branch.
349 This means that the diff between the topic branch base and head
350 (latest commit) is shown, appended to the description found in
351 the ``.topmsg`` file.
353 The patch is simply dumped to stdout. In the future, ``tg patch``
354 will be able to automatically send the patches by mail or save
355 them to files. (TODO)
358 -i base patch generation on index instead of branch
359 -w base patch generation on working tree instead of branch
363 Send a patch from the current or specified topic branch as
366 Takes the patch given on the command line and emails it out.
367 Destination addresses such as To, Cc and Bcc are taken from the
370 Since it actually boils down to ``git send-email``, please refer
371 to the documentation for that for details on how to setup email
372 for git. You can pass arbitrary options to this command through
373 the ``-s`` parameter, but you must double-quote everything. The
374 ``-r`` parameter with a msgid can be used to generate in-reply-to
375 and reference headers to an earlier mail.
377 WARNING: be careful when using this command. It easily sends
378 out several mails. You might want to run::
380 git config sendemail.confirm always
382 to let ``git send-email`` ask for confirmation before sending any
386 -i base patch generation on index instead of branch
387 -w base patch generation on working tree instead of branch
389 | TODO: ``tg mail patchfile`` to mail an already exported patch
390 | TODO: mailing patch series
391 | TODO: specifying additional options and addresses on command line
395 Register the given remote as TopGit-controlled. This will create
396 the namespace for the remote branch bases and teach ``git fetch``
397 to operate on them. However, from TopGit 0.8 onwards you need to
398 use ``tg push``, or ``git push --mirror``, for pushing
399 TopGit-controlled branches.
401 ``tg remote`` takes an optional remote name argument, and an
402 optional ``--populate`` switch. Use ``--populate`` for your
403 origin-style remotes: it will seed the local topic branch system
404 based on the remote topic branches. ``--populate`` will also make
405 ``tg remote`` automatically fetch the remote, and ``tg update`` look
406 at branches of this remote for updates by default.
410 Show overview of all TopGit-tracked topic branches and their
411 up-to-date status. With a branch name limit output to that branch:
414 marks the current topic branch
417 indicates that it introduces no changes of its own
420 indicates respectively whether it is local-only
424 indicates respectively if it is ahead or out-of-date
425 with respect to its remote mate
428 indicates that it is out-of-date with respect to its
432 indicates that it has missing dependencies [even if
433 they are recursive ones]
436 indicates that it is out-of-date with respect to
439 This can take a long time to accurately determine all the
440 relevant information about each branch; you can pass ``-t`` to get
441 just a terse list of topic branch names quickly. Alternately,
442 you can pass ``--graphviz`` to get a dot-suitable output to draw a
443 dependency graph between the topic branches.
445 You can also use the ``--sort`` option to sort the branches using
446 a topological sort. This is especially useful if each
447 TopGit-tracked topic branch depends on a single parent branch,
448 since it will then print the branches in the dependency order.
449 In more complex scenarios, a text graph view would be much more
450 useful, but that has not yet been implemented.
452 The --deps option outputs dependency information between
453 branches in a machine-readable format. Feed this to ``tsort`` to
454 get the output from --sort.
456 The --rdeps option outputs dependency information in an indended
457 text format that clearly shows all the dependencies and their
458 relationships to one another. By specifying a branch name the
459 dependency tree output can be limited to that for a single branch.
462 -i Use TopGit metadata from the index instead of the branch
463 -w Use TopGit metadata from the working tree instead of the branch
465 | TODO: Speed up by an order of magnitude
466 | TODO: Text graph view
470 Switch to a topic branch. You can use ``git checkout <branch>``
471 to get the same effect, but this command helps you navigate
472 the dependency graph, or allows you to match the topic branch
473 name using a regular expression, so it can be more convenient.
475 There following subcommands are available:
478 Check out a branch that directly
479 depends on your current branch.
482 Check out a branch that this branch
485 ``tg checkout goto <pattern>``
486 Check out a topic branch that
487 matches ``<pattern>``. ``<pattern>``
488 is used as a sed pattern to filter
489 all the topic branches.
492 An alias for ``push``.
494 ``tg checkout child``
495 An alias for ``push``.
498 An alias for ``push``.
501 An alias for ``pop``.
503 ``tg checkout parent``
504 An alias for ``pop``.
507 An alias for ``pop``.
509 If any of the above commands can find more than one possible
510 branch to switch to, you will be presented with the matches
511 and ask to select one of them.
513 The ``<pattern>`` of ``tg checkout goto`` is optional. If you don't
514 supply it, all the available topic branches are listed and you
515 can select one of them.
517 Normally, the ``push`` and ``pop`` commands moves one step in
518 the dependency graph of the topic branches. The ``-a`` option
519 causes them (and their aliases) to move as far as possible.
520 That is, ``tg checkout push -a`` moves to a topic branch that
521 depends (directly or indirectly) on the current branch and
522 that no other branch depends on. ``tg checkout pop -a``
523 moves to a regular branch that the current topic branch
524 depends on (directly or indirectly). If there is more than
525 one possibility, you will be prompted for your selection.
529 Export a tidied-up history of the current topic branch and its
530 dependencies, suitable for feeding upstream. Each topic branch
531 corresponds to a single commit or patch in the cleaned up
532 history (corresponding basically exactly to ``tg patch`` output
533 for the topic branch).
535 The command has three possible outputs now -- either a Git branch
536 with the collapsed history, a Git branch with a linearized
537 history, or a quilt series in new directory.
539 In the case where you are producing collapsed history in a new
540 branch, you can use this collapsed structure either for
541 providing a pull source for upstream, or for further
542 linearization e.g. for creation of a quilt series using git log::
544 git log --pretty=email -p --topo-order origin..exported
546 To better understand the function of ``tg export``, consider this
547 dependency structure::
549 origin/master - t/foo/blue - t/foo/red - master
550 `- t/bar/good <,----------'
551 `- t/baz ------------'
553 (where each of the branches may have a hefty history). Then::
555 master$ tg export for-linus
557 will create this commit structure on the branch ``for-linus``::
559 origin/master - t/foo/blue -. merge - t/foo/red -.. merge - master
560 `- t/bar/good <,-------------------'/
561 `- t/baz ---------------------'
563 In this mode, ``tg export`` works on the current topic branch, and
564 can be called either without an option (in that case,
565 ``--collapse`` is assumed), or with the ``--collapse`` option, and
566 with one mandatory argument: the name of the branch where the
567 exported result will be stored.
569 When using the linearize mode::
571 master$ tg export --linearize for-linus
573 you get a linear history respecting the dependencies of your
574 patches in a new branch ``for-linus``. The result should be more
575 or less the same as using quilt mode and then reimporting it
576 into a Git branch. (More or less because the topological order
577 can usually be extended in more than one way into a total order,
578 and the two methods may choose different ones.) The result
579 might be more appropriate for merging upstream, as it contains
582 Note that you might get conflicts during linearization because
583 the patches are reordered to get a linear history.
585 When using the quilt mode::
587 master$ tg export --quilt for-linus
589 would create the following directory ``for-linus``::
591 for-linus/t/foo/blue.diff
592 for-linus/t/foo/red.diff
593 for-linus/t/bar/good.diff
601 With ``--quilt``, you can also pass the ``-b`` parameter followed
602 by a comma-separated explicit list of branches to export, or
603 the ``--all`` parameter (which can be shortened to ``-a``) to
604 export them all. These options are currently only supported
607 In ``--quilt`` mode the patches are named like the originating
608 topgit branch. So usually they end up in subdirectories of the
609 output directory. With the ``--flatten`` option the names are
610 mangled so that they end up directly in the output dir (slashes
611 are substituted by underscores). With the ``--strip[=N]`` option
612 the first ``N`` subdirectories (all if no ``N`` is given) get
613 stripped off. Names are always ``--strip``'d before being
614 ``--flatten``'d. With the option ``--numbered`` (which implies
615 ``--flatten``) the patch names get a number as prefix to allow
616 getting the order without consulting the series file, which
617 eases sending out the patches.
619 | TODO: Make stripping of non-essential headers configurable
620 | TODO: Make stripping of [PATCH] and other prefixes configurable
621 | TODO: ``--mbox`` option to export instead as an mbox file
622 | TODO: support ``--all`` option in other modes of operation
623 | TODO: For quilt exporting, export the linearized history created in
624 a temporary branch--this would allow producing conflict-less
629 Import commits within the given revision range into TopGit,
630 creating one topic branch per commit. The dependencies are set
631 up to form a linear sequence starting on your current branch --
632 or a branch specified by the ``-d`` parameter, if present.
634 The branch names are auto-guessed from the commit messages and
635 prefixed by ``t/`` by default; use ``-p <prefix>`` to specify an
636 alternative prefix (even an empty one).
638 Alternatively, you can use the ``-s NAME`` parameter to specify
639 the name of the target branch; the command will then take one
640 more argument describing a *single* commit to import.
644 Update the current, specified or all topic branches with respect
645 to changes in the branches they depend on and remote branches.
646 This is performed in two phases -- first, changes within the
647 dependencies are merged to the base, then the base is merged
648 into the topic branch. The output will guide you on what to do
649 next in case of conflicts.
651 When ``-a`` is specifed, updates all topic branches matched by
652 ``<pattern>``'s (see ``git-for-each-ref(1)`` for details), or all
653 if no ``<pattern>`` is given. Any topic branches with missing
654 dependencies will be skipped entirely unless ``--skip`` is specified.
656 When ``--skip`` is specifed, an attempt is made to update topic
657 branches with missing dependencies by skipping only the dependencies
658 that are missing. Caveat utilitor
660 After the update, if a single topic branch was specified, it is
661 left as the current one; if ``-a`` was specified, it returns to
662 the branch which was current at the beginning.
664 If your dependencies are not up-to-date, ``tg update`` will first
665 recurse into them and update them.
667 If a remote branch update brings in dependencies on branches
668 that are not yet instantiated locally, you can either bring in
669 all the new branches from the remote using ``tg remote
670 --populate``, or only pick out the missing ones using ``tg create
671 -r`` (``tg summary`` will point out branches with incomplete
672 dependencies by showing an ``!`` next to them).
674 | TODO: ``tg update -a -c`` to autoremove (clean) up-to-date branches
678 If ``-a`` or ``--all`` was specified, pushes all non-annihilated
679 TopGit-controlled topic branches, to a remote repository.
680 Otherwise, pushes the specified topic branches -- or the
681 current branch, if you don't specify which. By default, the
682 remote gets all the dependencies (both TopGit-controlled and
683 non-TopGit-controlled) and bases pushed to it too. If
684 ``--tgish-only`` was specified, only TopGit-controlled
685 dependencies will be pushed, and if ``--no-deps`` was specified,
686 no dependencies at all will be pushed.
688 The remote may be specified with the ``-r`` option. If no remote
689 was specified, the configured default TopGit remote will be
694 Prints the base commit of each of the named topic branches, or
695 the current branch if no branches are named. Prints an error
696 message and exits with exit code 1 if the named branch is not
701 Prints the git log of the named topgit branch -- or the current
702 branch, if you don't specify a name.
704 NOTE: if you have merged changes from a different repository, this
705 command might not list all interesting commits.
709 Outputs the direct dependencies for the current or named branch.
712 -i show dependencies based on index instead of branch
713 -w show dependencies based on working tree instead of branch
717 Outputs all branches which directly depend on the current or
721 -i show dependencies based on index instead of branch
722 -w show dependencies based on working tree instead of branch
730 TopGit stores all the topic branches in the regular ``refs/heads/``
731 namespace (so we recommend distinguishing them with the ``t/`` prefix).
732 Apart from that, TopGit also maintains a set of auxiliary refs in
733 ``refs/top-*``. Currently, only ``refs/top-bases/`` is used, containing the
734 current *base* of the given topic branch -- this is basically a merge of
735 all the branches the topic branch depends on; it is updated during ``tg
736 update`` and then merged to the topic branch, and it is the base of a
737 patch generated from the topic branch by ``tg patch``.
739 All the metadata is tracked within the source tree and history of the
740 topic branch itself, in ``.top*`` files; these files are kept isolated
741 within the topic branches during TopGit-controlled merges and are of
742 course omitted during ``tg patch``. The state of these files in base
743 commits is undefined; look at them only in the topic branches
744 themselves. Currently, two files are defined:
747 Contains the description of the topic branch in a
748 mail-like format, plus the author information, whatever
749 Cc headers you choose or the post-three-dashes message.
750 When mailing out your patch, basically only a few extra
751 mail headers are inserted and then the patch itself is
752 appended. Thus, as your patches evolve, you can record
753 nuances like whether the particular patch should have
754 To-list / Cc-maintainer or vice-versa and similar
755 nuances, if your project is into that. ``From`` is
756 prefilled from your current ``GIT_AUTHOR_IDENT``; other
757 headers can be prefilled from various optional
758 ``topgit.*`` git config options.
761 Contains the one-per-line list of branches this branch
762 depends on, pre-seeded by `tg create`. A (continuously
763 updated) merge of these branches will be the *base* of
766 IMPORTANT: DO NOT EDIT ``.topdeps`` MANUALLY!!! If you do so, you need to
767 know exactly what are you doing, since this file must stay in sync with
768 the Git history information, otherwise very bad things will happen.
770 TopGit also automagically installs a bunch of custom commit-related
771 hooks that will verify whether you are committing the ``.top*`` files in a
772 sane state. It will add the hooks to separate files within the ``hooks/``
773 subdirectory, and merely insert calls to them to the appropriate hooks
774 and make them executable (but will make sure the original hook's code is
775 not called if the hook was not executable beforehand).
777 Another automagically installed piece is a ``.git/info/attributes``
778 specifier for an ``ours`` merge strategy for the files ``.topmsg`` and
779 ``.topdeps``, and the (intuitive) ``ours`` merge strategy definition in
786 There are two remaining issues with accessing topic branches in remote
789 (i) Referring to remote topic branches from your local repository
790 (ii) Developing some of the remote topic branches locally
792 There are two somewhat contradictory design considerations here:
794 (a) Hacking on multiple independent TopGit remotes in a single
796 (b) Having a self-contained topic system in local refs space
798 To us, (a) does not appear to be very convincing, while (b) is quite
799 desirable for ``git-log topic`` etc. working, and increased conceptual
802 Thus, we choose to instantiate all the topic branches of given remote
803 locally; this is performed by ``tg remote --populate``. ``tg update``
804 will also check if a branch can be updated from its corresponding remote
805 branch. The logic needs to be somewhat involved if we are to "do the
806 right thing". First, we update the base, handling the remote branch as
807 if it was the first dependency; thus, conflict resolutions made in the
808 remote branch will be carried over to our local base automagically.
809 Then, the base is merged into the remote branch and the result is merged
810 to the local branch -- again, to carry over remote conflict resolutions.
811 In the future, this order might be adjustable on a per-update basis, in
812 case local changes happen to be diverging more than the remote ones.
814 All commands by default refer to the remote that ``tg remote --populate``
815 was called on the last time (stored in the ``topgit.remote`` git
816 configuration variable). You can manually run any command with a
817 different base remote by passing ``-r REMOTE`` *before* the subcommand
824 The following references are useful to understand the development of
825 topgit and its subcommands.
828 http://lists-archives.org/git/688698-add-list-and-rm-sub-commands-to-tg-depend.html
834 The following software understands TopGit branches:
836 * `magit <http://magit.github.io/>`_ -- a git mode for emacs
838 IMPORTANT: Magit requires its topgit mode to be enabled first, as
839 described in its documentation, in the "Activating extensions"
840 subsection. If this is not done, it will not push TopGit branches
841 correctly, so it's important to enable it even if you plan to mostly use
842 TopGit from the command line.