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
226 ``tg [-C <dir>] [-r <remote> | -u] <subcommand> [<subcommand option/argument>...]``
228 -C <dir> Change directory to <dir> before doing anything
229 -r <remote> Pretend ``topgit.remote`` is set to <remote>
230 -u Pretend ``topgit.remote`` is not set
232 The ``tg`` tool has several subcommands:
236 Our sophisticated integrated help facility. Mostly duplicates
241 # to get help for a particular command:
243 # to get help for a particular command in a browser window:
244 $ tg help -w <command>
245 # to get help on TopGit itself
247 # to get help on TopGit itself in a browser
252 Create a new TopGit-controlled topic branch of the given name
253 (required argument) and switch to it. If no dependencies are
254 specified (by extra arguments passed after the first one), the
255 current branch is assumed to be the only dependency.
257 After ``tg create``, you should insert the patch description into
258 the ``.topmsg`` file, which will already contain some prefilled
259 bits. You can set the ``topgit.to``, ``topgit.cc`` and ``topgit.bcc``
260 git configuration variables (see ``man git-config``) in order to
261 have ``tg create`` add these headers with the given default values
264 The main task of ``tg create`` is to set up the topic branch base
265 from the dependencies. This may fail due to merge conflicts.
266 In that case, after you commit the conflict resolution, you
267 should call ``tg create`` again (without any arguments); it will
268 detect that you are on a topic branch base ref and resume the
269 topic branch creation operation.
271 In an alternative use case, if ``-r <branch>`` is given instead of a
272 dependency list, the topic branch is created based on the given
273 remote branch. With just ``-r`` the remote branch name is assumed
274 to be the same as the local topic branch being created.
278 Remove a TopGit-controlled topic branch of the given name
279 (required argument). Normally, this command will remove only an
280 empty branch (base == head) without dependendents; use ``-f`` to
281 remove a non-empty branch or a branch that is depended upon by
284 The ``-f`` option is also useful to force removal of a branch's
285 base, if you used ``git branch -D B`` to remove branch B, and then
286 certain TopGit commands complain, because the base of branch B
289 IMPORTANT: Currently, this command will *NOT* remove the branch
290 from the dependency list in other branches. You need to take
291 care of this *manually*. This is even more complicated in
292 combination with ``-f`` -- in that case, you need to manually
293 unmerge the removed branch's changes from the branches depending
296 See also ``tg annihilate``.
298 | TODO: ``-a`` to delete all empty branches, depfix, revert
302 Make a commit on the current TopGit-controlled topic branch
303 that makes it equal to its base, including the presence or
304 absence of .topmsg and .topdeps. Annihilated branches are not
305 displayed by ``tg summary``, so they effectively get out of your
306 way. However, the branch still exists, and ``tg push`` will
307 push it (except if given the ``-a`` option). This way, you can
308 communicate that the branch is no longer wanted.
310 When annihilating a branch that has dependents (i.e. branches
311 that depend on it), those dependents have the dependencies of
312 the branch being annihilated added to them if they do not already
313 have them as dependencies. Essentially the DAG is repaired to
314 skip over the annihilated branch.
316 Normally, this command will remove only an empty branch
317 (base == head, except for changes to the .top* files); use
318 ``-f`` to annihilate a non-empty branch.
322 Change the dependencies of a TopGit-controlled topic branch.
323 This should have several subcommands, but only ``add`` is
326 The ``add`` subcommand takes an argument naming a topic branch to
327 be added, adds it to ``.topdeps``, performs a commit and then
328 updates your topic branch accordingly. If you want to do other
329 things related to the dependency addition, like adjusting
330 ``.topmsg``, prepare them in the index before calling ``tg depend
333 You have enabled ``git rerere`` haven't you?
335 | TODO: Subcommand for removing dependencies, obviously
339 List files changed by the current or specified topic branch.
342 -i list files based on index instead of branch
343 -w list files based on working tree instead of branch
347 Show summary information about the current or specified topic
350 Numbers in parenthesis after a branch name such as "(11/3 commits)"
351 indicate how many commits on the branch (11) and how many of those
352 are non-merge commits (3).
356 Generate a patch from the current or specified topic branch.
357 This means that the diff between the topic branch base and head
358 (latest commit) is shown, appended to the description found in
359 the ``.topmsg`` file.
361 The patch is simply dumped to stdout. In the future, ``tg patch``
362 will be able to automatically send the patches by mail or save
363 them to files. (TODO)
366 -i base patch generation on index instead of branch
367 -w base patch generation on working tree instead of branch
368 --binary pass --binary to ``git diff-tree`` to enable generation
370 --diff-opt options after the branch name (and an optional ``--``)
371 are passed directly to ``git diff-tree``
373 In order to pass a sole explicit ``-w`` through to ``git diff-tree`` it
374 must be separated from the ``tg`` options by an explicit ``--``.
375 Or it can be spelled as ``--ignore-all-space`` to distinguuish it from
376 ``tg``'s ``-w`` option.
378 If additional non-``tg`` options are passed through to
379 ``git diff-tree`` (other than ``--binary`` which is fully supported)
380 the resulting ``tg patch`` output may not be appliable.
384 Send a patch from the current or specified topic branch as
387 Takes the patch given on the command line and emails it out.
388 Destination addresses such as To, Cc and Bcc are taken from the
391 Since it actually boils down to ``git send-email``, please refer
392 to the documentation for that for details on how to setup email
393 for git. You can pass arbitrary options to this command through
394 the ``-s`` parameter, but you must double-quote everything. The
395 ``-r`` parameter with a msgid can be used to generate in-reply-to
396 and reference headers to an earlier mail.
398 WARNING: be careful when using this command. It easily sends
399 out several mails. You might want to run::
401 git config sendemail.confirm always
403 to let ``git send-email`` ask for confirmation before sending any
407 -i base patch generation on index instead of branch
408 -w base patch generation on working tree instead of branch
410 | TODO: ``tg mail patchfile`` to mail an already exported patch
411 | TODO: mailing patch series
412 | TODO: specifying additional options and addresses on command line
416 Register the given remote as TopGit-controlled. This will create
417 the namespace for the remote branch bases and teach ``git fetch``
418 to operate on them. However, from TopGit 0.8 onwards you need to
419 use ``tg push``, or ``git push --mirror``, for pushing
420 TopGit-controlled branches.
422 ``tg remote`` takes an optional remote name argument, and an
423 optional ``--populate`` switch. Use ``--populate`` for your
424 origin-style remotes: it will seed the local topic branch system
425 based on the remote topic branches. ``--populate`` will also make
426 ``tg remote`` automatically fetch the remote, and ``tg update`` look
427 at branches of this remote for updates by default.
429 Using ``--populate`` with a remote name causes the ``topgit.remote``
430 git configuration variable to be set to the given remote name.
434 Show overview of all TopGit-tracked topic branches and their
435 up-to-date status. With a branch name limit output to that branch.
436 Using ``--rdeps`` changes the default from all branches to just the
437 current ``HEAD`` branch but using ``--all`` as the branch name will
438 show ``--rdeps`` for all branches.
441 marks the current topic branch
444 indicates that it introduces no changes of its own
447 indicates respectively whether it is local-only
451 indicates respectively if it is ahead or out-of-date
452 with respect to its remote mate
455 indicates that it is out-of-date with respect to its
459 indicates that it has missing dependencies [even if
460 they are recursive ones]
463 indicates that it is out-of-date with respect to
466 This can take a long time to accurately determine all the
467 relevant information about each branch; you can pass ``-t`` to get
468 just a terse list of topic branch names quickly. Alternately,
469 you can pass ``--graphviz`` to get a dot-suitable output to draw a
470 dependency graph between the topic branches.
472 You can also use the ``--sort`` option to sort the branches using
473 a topological sort. This is especially useful if each
474 TopGit-tracked topic branch depends on a single parent branch,
475 since it will then print the branches in the dependency order.
476 In more complex scenarios, a text graph view would be much more
477 useful, but that has not yet been implemented.
479 The --deps option outputs dependency information between
480 branches in a machine-readable format. Feed this to ``tsort`` to
481 get the output from --sort.
483 The --rdeps option outputs dependency information in an indented
484 text format that clearly shows all the dependencies and their
485 relationships to one another. When --rdeps is given the default is
486 to just display information for HEAD, but that can be changed by using
487 --all as the branch name.
489 With --exclude branch, branch can be excluded from the output meaning
490 it will be skipped and its name will be omitted from any dependency
491 output. The --exclude option may be repeated to omit more than one
492 branch from the output. Limiting the output to a single branch that
493 has been excluded will result in no output at all.
495 Note that the branch name can be specified as ``HEAD`` as a shortcut for
496 the TopGit-controlled branch that ``HEAD`` is a symbolic ref to.
499 -i Use TopGit metadata from the index instead of the branch
500 -w Use TopGit metadata from the working tree instead of the branch
505 Switch to a topic branch. You can use ``git checkout <branch>``
506 to get the same effect, but this command helps you navigate
507 the dependency graph, or allows you to match the topic branch
508 name using a regular expression, so it can be more convenient.
510 There following subcommands are available:
513 Check out a branch that directly
514 depends on your current branch.
517 Check out a branch that this branch
520 ``tg checkout goto <pattern>``
521 Check out a topic branch that
522 matches ``<pattern>``. ``<pattern>``
523 is used as a sed pattern to filter
524 all the topic branches.
527 An alias for ``push``.
529 ``tg checkout child``
530 An alias for ``push``.
533 An alias for ``push``.
536 An alias for ``pop``.
538 ``tg checkout parent``
539 An alias for ``pop``.
542 An alias for ``pop``.
544 If any of the above commands can find more than one possible
545 branch to switch to, you will be presented with the matches
546 and ask to select one of them.
548 The ``<pattern>`` of ``tg checkout goto`` is optional. If you don't
549 supply it, all the available topic branches are listed and you
550 can select one of them.
552 Normally, the ``push`` and ``pop`` commands moves one step in
553 the dependency graph of the topic branches. The ``-a`` option
554 causes them (and their aliases) to move as far as possible.
555 That is, ``tg checkout push -a`` moves to a topic branch that
556 depends (directly or indirectly) on the current branch and
557 that no other branch depends on. ``tg checkout pop -a``
558 moves to a regular branch that the current topic branch
559 depends on (directly or indirectly). If there is more than
560 one possibility, you will be prompted for your selection.
564 Export a tidied-up history of the current topic branch and its
565 dependencies, suitable for feeding upstream. Each topic branch
566 corresponds to a single commit or patch in the cleaned up
567 history (corresponding basically exactly to ``tg patch`` output
568 for the topic branch).
570 The command has three possible outputs now -- either a Git branch
571 with the collapsed history, a Git branch with a linearized
572 history, or a quilt series in new directory.
574 In the case where you are producing collapsed history in a new
575 branch, you can use this collapsed structure either for
576 providing a pull source for upstream, or for further
577 linearization e.g. for creation of a quilt series using git log::
579 git log --pretty=email -p --topo-order origin..exported
581 To better understand the function of ``tg export``, consider this
582 dependency structure::
584 origin/master - t/foo/blue - t/foo/red - master
585 `- t/bar/good <,----------'
586 `- t/baz ------------'
588 (where each of the branches may have a hefty history). Then::
590 master$ tg export for-linus
592 will create this commit structure on the branch ``for-linus``::
594 origin/master - t/foo/blue -. merge - t/foo/red -.. merge - master
595 `- t/bar/good <,-------------------'/
596 `- t/baz ---------------------'
598 In this mode, ``tg export`` works on the current topic branch, and
599 can be called either without an option (in that case,
600 ``--collapse`` is assumed), or with the ``--collapse`` option, and
601 with one mandatory argument: the name of the branch where the
602 exported result will be stored.
604 When using the linearize mode::
606 master$ tg export --linearize for-linus
608 you get a linear history respecting the dependencies of your
609 patches in a new branch ``for-linus``. The result should be more
610 or less the same as using quilt mode and then reimporting it
611 into a Git branch. (More or less because the topological order
612 can usually be extended in more than one way into a total order,
613 and the two methods may choose different ones.) The result
614 might be more appropriate for merging upstream, as it contains
617 Note that you might get conflicts during linearization because
618 the patches are reordered to get a linear history. If linearization
619 would produce conflicts then using ``--quilt`` will also likely result
620 in conflicts when the exported quilt series is applied. Since the
621 ``--quilt`` mode simply runs a series of ``tg patch`` commands to
622 generate the patches in the exported quilt series and those patches
623 will end up being applied linearly, the same conflicts that would be
624 produced by the ``--linearize`` option will then occur at that time.
626 To avoid conflicts produced by ``--linearize`` (or by applying the
627 ``--quilt`` output), use the default ``--collapse`` mode and then use
628 ``git rebase -m`` on the collapsed branch (with a suitable <upstream>)
629 followed by ``git format-patch`` on the rebased result to produce a
630 conflict-free patch set.
632 You have enabled ``git rerere`` haven't you?
634 When using the quilt mode::
636 master$ tg export --quilt for-linus
638 would create the following directory ``for-linus``::
640 for-linus/t/foo/blue.diff
641 for-linus/t/foo/red.diff
642 for-linus/t/bar/good.diff
650 With ``--quilt``, you can also pass the ``-b`` parameter followed
651 by a comma-separated explicit list of branches to export, or
652 the ``--all`` parameter (which can be shortened to ``-a``) to
653 export them all. The ``--binary`` option enables producing Git
654 binary patches. These options are currently only supported
657 In ``--quilt`` mode the patches are named like the originating
658 topgit branch. So usually they end up in subdirectories of the
659 output directory. With the ``--flatten`` option the names are
660 mangled so that they end up directly in the output dir (slashes
661 are substituted by underscores). With the ``--strip[=N]`` option
662 the first ``N`` subdirectories (all if no ``N`` is given) get
663 stripped off. Names are always ``--strip``'d before being
664 ``--flatten``'d. With the option ``--numbered`` (which implies
665 ``--flatten``) the patch names get a number as prefix to allow
666 getting the order without consulting the series file, which
667 eases sending out the patches.
669 | TODO: Make stripping of non-essential headers configurable
670 | TODO: Make stripping of [PATCH] and other prefixes configurable
671 | TODO: ``--mbox`` option to export instead as an mbox file
672 | TODO: support ``--all`` option in other modes of operation
673 | TODO: For quilt exporting, export the linearized history created in
674 a temporary branch--this would allow producing conflict-less
679 Import commits within the given revision range into TopGit,
680 creating one topic branch per commit. The dependencies are set
681 up to form a linear sequence starting on your current branch --
682 or a branch specified by the ``-d`` parameter, if present.
684 The branch names are auto-guessed from the commit messages and
685 prefixed by ``t/`` by default; use ``-p <prefix>`` to specify an
686 alternative prefix (even an empty one).
688 Alternatively, you can use the ``-s NAME`` parameter to specify
689 the name of the target branch; the command will then take one
690 more argument describing a *single* commit to import.
694 Update the current, specified or all topic branches with respect
695 to changes in the branches they depend on and remote branches.
696 This is performed in two phases -- first, changes within the
697 dependencies are merged to the base, then the base is merged
698 into the topic branch. The output will guide you on what to do
699 next in case of conflicts.
701 You have enabled ``git rerere`` haven't you?
703 When ``-a`` is specifed, updates all topic branches matched by
704 ``<pattern>``'s (see ``git-for-each-ref(1)`` for details), or all
705 if no ``<pattern>`` is given. Any topic branches with missing
706 dependencies will be skipped entirely unless ``--skip`` is specified.
708 When ``--skip`` is specifed, an attempt is made to update topic
709 branches with missing dependencies by skipping only the dependencies
710 that are missing. Caveat utilitor
712 After the update, if a single topic branch was specified, it is
713 left as the current one; if ``-a`` was specified, it returns to
714 the branch which was current at the beginning.
716 If your dependencies are not up-to-date, ``tg update`` will first
717 recurse into them and update them.
719 If a remote branch update brings in dependencies on branches
720 that are not yet instantiated locally, you can either bring in
721 all the new branches from the remote using ``tg remote
722 --populate``, or only pick out the missing ones using ``tg create
723 -r`` (``tg summary`` will point out branches with incomplete
724 dependencies by showing an ``!`` next to them).
726 | TODO: ``tg update -a -c`` to autoremove (clean) up-to-date branches
730 If ``-a`` or ``--all`` was specified, pushes all non-annihilated
731 TopGit-controlled topic branches, to a remote repository.
732 Otherwise, pushes the specified topic branches -- or the
733 current branch, if you don't specify which. By default, the
734 remote gets all the dependencies (both TopGit-controlled and
735 non-TopGit-controlled) and bases pushed to it too. If
736 ``--tgish-only`` was specified, only TopGit-controlled
737 dependencies will be pushed, and if ``--no-deps`` was specified,
738 no dependencies at all will be pushed.
740 The ``--dry-run`` and ``--force`` options are passed directly to
741 ``git push`` if given.
743 The remote may be specified with the ``-r`` option. If no remote
744 was specified, the configured default TopGit remote will be
749 Prints the base commit of each of the named topic branches, or
750 the current branch if no branches are named. Prints an error
751 message and exits with exit code 1 if the named branch is not
756 Prints the git log of the named topgit branch -- or the current
757 branch, if you don't specify a name.
759 NOTE: if you have merged changes from a different repository, this
760 command might not list all interesting commits.
764 Outputs the direct dependencies for the current or named branch.
767 -i show dependencies based on index instead of branch
768 -w show dependencies based on working tree instead of branch
772 Outputs all branches which directly depend on the current or
776 -i show dependencies based on index instead of branch
777 -w show dependencies based on working tree instead of branch
785 TopGit stores all the topic branches in the regular ``refs/heads/``
786 namespace (so we recommend distinguishing them with the ``t/`` prefix).
787 Apart from that, TopGit also maintains a set of auxiliary refs in
788 ``refs/top-*``. Currently, only ``refs/top-bases/`` is used, containing the
789 current *base* of the given topic branch -- this is basically a merge of
790 all the branches the topic branch depends on; it is updated during ``tg
791 update`` and then merged to the topic branch, and it is the base of a
792 patch generated from the topic branch by ``tg patch``.
794 All the metadata is tracked within the source tree and history of the
795 topic branch itself, in ``.top*`` files; these files are kept isolated
796 within the topic branches during TopGit-controlled merges and are of
797 course omitted during ``tg patch``. The state of these files in base
798 commits is undefined; look at them only in the topic branches
799 themselves. Currently, two files are defined:
802 Contains the description of the topic branch in a
803 mail-like format, plus the author information, whatever
804 Cc headers you choose or the post-three-dashes message.
805 When mailing out your patch, basically only a few extra
806 mail headers are inserted and then the patch itself is
807 appended. Thus, as your patches evolve, you can record
808 nuances like whether the particular patch should have
809 To-list / Cc-maintainer or vice-versa and similar
810 nuances, if your project is into that. ``From`` is
811 prefilled from your current ``GIT_AUTHOR_IDENT``; other
812 headers can be prefilled from various optional
813 ``topgit.*`` git config options.
816 Contains the one-per-line list of branches this branch
817 depends on, pre-seeded by `tg create`. A (continuously
818 updated) merge of these branches will be the *base* of
821 IMPORTANT: DO NOT EDIT ``.topdeps`` MANUALLY!!! If you do so, you need to
822 know exactly what are you doing, since this file must stay in sync with
823 the Git history information, otherwise very bad things will happen.
825 TopGit also automagically installs a bunch of custom commit-related
826 hooks that will verify whether you are committing the ``.top*`` files in a
827 sane state. It will add the hooks to separate files within the ``hooks/``
828 subdirectory, and merely insert calls to them to the appropriate hooks
829 and make them executable (but will make sure the original hook's code is
830 not called if the hook was not executable beforehand).
832 Another automagically installed piece is a ``.git/info/attributes``
833 specifier for an ``ours`` merge strategy for the files ``.topmsg`` and
834 ``.topdeps``, and the (intuitive) ``ours`` merge strategy definition in
841 There are two remaining issues with accessing topic branches in remote
844 (i) Referring to remote topic branches from your local repository
845 (ii) Developing some of the remote topic branches locally
847 There are two somewhat contradictory design considerations here:
849 (a) Hacking on multiple independent TopGit remotes in a single
851 (b) Having a self-contained topic system in local refs space
853 To us, (a) does not appear to be very convincing, while (b) is quite
854 desirable for ``git-log topic`` etc. working, and increased conceptual
857 Thus, we choose to instantiate all the topic branches of given remote
858 locally; this is performed by ``tg remote --populate``. ``tg update``
859 will also check if a branch can be updated from its corresponding remote
860 branch. The logic needs to be somewhat involved if we are to "do the
861 right thing". First, we update the base, handling the remote branch as
862 if it was the first dependency; thus, conflict resolutions made in the
863 remote branch will be carried over to our local base automagically.
864 Then, the base is merged into the remote branch and the result is merged
865 to the local branch -- again, to carry over remote conflict resolutions.
866 In the future, this order might be adjustable on a per-update basis, in
867 case local changes happen to be diverging more than the remote ones.
869 All commands by default refer to the remote that ``tg remote --populate``
870 was called on the last time (stored in the ``topgit.remote`` git
871 configuration variable). You can manually run any command with a
872 different base remote by passing ``-r REMOTE`` *before* the subcommand
879 The following references are useful to understand the development of
880 topgit and its subcommands.
883 http://lists-archives.org/git/688698-add-list-and-rm-sub-commands-to-tg-depend.html
889 The following software understands TopGit branches:
891 * `magit <http://magit.github.io/>`_ -- a git mode for emacs
893 IMPORTANT: Magit requires its topgit mode to be enabled first, as
894 described in its documentation, in the "Activating extensions"
895 subsection. If this is not done, it will not push TopGit branches
896 correctly, so it's important to enable it even if you plan to mostly use
897 TopGit from the command line.