summaryrefslogtreecommitdiff
path: root/Documentation/howto
diff options
context:
space:
mode:
authorLibravatar Junio C Hamano <gitster@pobox.com>2008-02-22 22:54:37 -0800
committerLibravatar Junio C Hamano <gitster@pobox.com>2008-02-22 22:54:37 -0800
commit50f3ac29cbadbf7e0ff099b493b00cfa4129e1e0 (patch)
tree72b756b4c7d60709b7484cceeb3a1d82a18a86af /Documentation/howto
parentbuiltin-reflog.c: fix typo that accesses an unset variable (diff)
parentbuiltin-reflog.c: don't install new reflog on write failure (diff)
downloadtgif-50f3ac29cbadbf7e0ff099b493b00cfa4129e1e0.tar.xz
Merge branch 'bc/reflog-fix' into js/reflog-delete
* bc/reflog-fix: (1490 commits) builtin-reflog.c: don't install new reflog on write failure hash: fix lookup_hash semantics gitweb: Better chopping in commit search results builtin-tag.c: remove cruft git-merge-index documentation: clarify synopsis send-email: fix In-Reply-To regression git-reset --hard and git-read-tree --reset: fix read_cache_unmerged() Teach git-grep --name-only as synonym for -l diff: fix java funcname pattern for solaris t3404: use configured shell instead of /bin/sh git_config_*: don't assume we are parsing a config file prefix_path: use is_absolute_path() instead of *orig == '/' git-clean: handle errors if removing files fails Clarified the meaning of git-add -u in the documentation git-clone.sh: properly configure remote even if remote's head is dangling git.el: Set process-environment instead of invoking env Documentation/git-stash: document options for git stash list send-email: squelch warning due to comparing undefined $_ to "" cvsexportcommit: be graceful when "cvs status" reorders the arguments Rename git-core rpm to just git and rename the meta-pacakge to git-all. ... Conflicts: Documentation/git-reflog.txt t/t1410-reflog.sh
Diffstat (limited to 'Documentation/howto')
-rw-r--r--Documentation/howto/maintain-git.txt277
-rw-r--r--Documentation/howto/recover-corrupted-blob-object.txt134
-rw-r--r--Documentation/howto/using-merge-subtree.txt75
3 files changed, 486 insertions, 0 deletions
diff --git a/Documentation/howto/maintain-git.txt b/Documentation/howto/maintain-git.txt
new file mode 100644
index 0000000000..4357e26913
--- /dev/null
+++ b/Documentation/howto/maintain-git.txt
@@ -0,0 +1,277 @@
+From: Junio C Hamano <gitster@pobox.com>
+Date: Wed, 21 Nov 2007 16:32:55 -0800
+Subject: Addendum to "MaintNotes"
+Abstract: Imagine that git development is racing along as usual, when our friendly
+ neighborhood maintainer is struck down by a wayward bus. Out of the
+ hordes of suckers (loyal developers), you have been tricked (chosen) to
+ step up as the new maintainer. This howto will show you "how to" do it.
+
+The maintainer's git time is spent on three activities.
+
+ - Communication (60%)
+
+ Mailing list discussions on general design, fielding user
+ questions, diagnosing bug reports; reviewing, commenting on,
+ suggesting alternatives to, and rejecting patches.
+
+ - Integration (30%)
+
+ Applying new patches from the contributors while spotting and
+ correcting minor mistakes, shuffling the integration and
+ testing branches, pushing the results out, cutting the
+ releases, and making announcements.
+
+ - Own development (10%)
+
+ Scratching my own itch and sending proposed patch series out.
+
+The policy on Integration is informally mentioned in "A Note
+from the maintainer" message, which is periodically posted to
+this mailing list after each feature release is made.
+
+The policy.
+
+ - Feature releases are numbered as vX.Y.Z and are meant to
+ contain bugfixes and enhancements in any area, including
+ functionality, performance and usability, without regression.
+
+ - Maintenance releases are numbered as vX.Y.Z.W and are meant
+ to contain only bugfixes for the corresponding vX.Y.Z feature
+ release and earlier maintenance releases vX.Y.Z.V (V < W).
+
+ - 'master' branch is used to prepare for the next feature
+ release. In other words, at some point, the tip of 'master'
+ branch is tagged with vX.Y.Z.
+
+ - 'maint' branch is used to prepare for the next maintenance
+ release. After the feature release vX.Y.Z is made, the tip
+ of 'maint' branch is set to that release, and bugfixes will
+ accumulate on the branch, and at some point, the tip of the
+ branch is tagged with vX.Y.Z.1, vX.Y.Z.2, and so on.
+
+ - 'next' branch is used to publish changes (both enhancements
+ and fixes) that (1) have worthwhile goal, (2) are in a fairly
+ good shape suitable for everyday use, (3) but have not yet
+ demonstrated to be regression free. New changes are tested
+ in 'next' before merged to 'master'.
+
+ - 'pu' branch is used to publish other proposed changes that do
+ not yet pass the criteria set for 'next'.
+
+ - The tips of 'master', 'maint' and 'next' branches will always
+ fast forward, to allow people to build their own
+ customization on top of them.
+
+ - Usually 'master' contains all of 'maint', 'next' contains all
+ of 'master' and 'pu' contains all of 'next'.
+
+ - The tip of 'master' is meant to be more stable than any
+ tagged releases, and the users are encouraged to follow it.
+
+ - The 'next' branch is where new action takes place, and the
+ users are encouraged to test it so that regressions and bugs
+ are found before new topics are merged to 'master'.
+
+
+A typical git day for the maintainer implements the above policy
+by doing the following:
+
+ - Scan mailing list and #git channel log. Respond with review
+ comments, suggestions etc. Kibitz. Collect potentially
+ usable patches from the mailing list. Patches about a single
+ topic go to one mailbox (I read my mail in Gnus, and type
+ \C-o to save/append messages in files in mbox format).
+
+ - Review the patches in the saved mailboxes. Edit proposed log
+ message for typofixes and clarifications, and add Acks
+ collected from the list. Edit patch to incorporate "Oops,
+ that should have been like this" fixes from the discussion.
+
+ - Classify the collected patches and handle 'master' and
+ 'maint' updates:
+
+ - Obviously correct fixes that pertain to the tip of 'maint'
+ are directly applied to 'maint'.
+
+ - Obviously correct fixes that pertain to the tip of 'master'
+ are directly applied to 'master'.
+
+ This step is done with "git am".
+
+ $ git checkout master ;# or "git checkout maint"
+ $ git am -3 -s mailbox
+ $ make test
+
+ - Merge downwards (maint->master):
+
+ $ git checkout master
+ $ git merge maint
+ $ make test
+
+ - Review the last issue of "What's cooking" message, review the
+ topics scheduled for merging upwards (topic->master and
+ topic->maint), and merge.
+
+ $ git checkout master ;# or "git checkout maint"
+ $ git merge ai/topic ;# or "git merge ai/maint-topic"
+ $ git log -p ORIG_HEAD.. ;# final review
+ $ git diff ORIG_HEAD.. ;# final review
+ $ make test ;# final review
+ $ git branch -d ai/topic ;# or "git branch -d ai/maint-topic"
+
+ - Merge downwards (maint->master) if needed:
+
+ $ git checkout master
+ $ git merge maint
+ $ make test
+
+ - Merge downwards (master->next) if needed:
+
+ $ git checkout next
+ $ git merge master
+ $ make test
+
+ - Handle the remaining patches:
+
+ - Anything unobvious that is applicable to 'master' (in other
+ words, does not depend on anything that is still in 'next'
+ and not in 'master') is applied to a new topic branch that
+ is forked from the tip of 'master'. This includes both
+ enhancements and unobvious fixes to 'master'. A topic
+ branch is named as ai/topic where "ai" is typically
+ author's initial and "topic" is a descriptive name of the
+ topic (in other words, "what's the series is about").
+
+ - An unobvious fix meant for 'maint' is applied to a new
+ topic branch that is forked from the tip of 'maint'. The
+ topic is named as ai/maint-topic.
+
+ - Changes that pertain to an existing topic are applied to
+ the branch, but:
+
+ - obviously correct ones are applied first;
+
+ - questionable ones are discarded or applied to near the tip;
+
+ - Replacement patches to an existing topic are accepted only
+ for commits not in 'next'.
+
+ The above except the "replacement" are all done with:
+
+ $ git am -3 -s mailbox
+
+ while patch replacement is often done by:
+
+ $ git format-patch ai/topic~$n..ai/topic ;# export existing
+
+ then replace some parts with the new patch, and reapplying:
+
+ $ git reset --hard ai/topic~$n
+ $ git am -3 -s 000*.txt
+
+ The full test suite is always run for 'maint' and 'master'
+ after patch application; for topic branches the tests are run
+ as time permits.
+
+ - Update "What's cooking" message to review the updates to
+ existing topics, newly added topics and graduated topics.
+
+ This step is helped with Meta/UWC script (where Meta/ contains
+ a checkout of the 'todo' branch).
+
+ - Merge topics to 'next'. For each branch whose tip is not
+ merged to 'next', one of three things can happen:
+
+ - The commits are all next-worthy; merge the topic to next:
+
+ $ git checkout next
+ $ git merge ai/topic ;# or "git merge ai/maint-topic"
+ $ make test
+
+ - The new parts are of mixed quality, but earlier ones are
+ next-worthy; merge the early parts to next:
+
+ $ git checkout next
+ $ git merge ai/topic~2 ;# the tip two are dubious
+ $ make test
+
+ - Nothing is next-worthy; do not do anything.
+
+ - Rebase topics that do not have any commit in next yet. This
+ step is optional but sometimes is worth doing when an old
+ series that is not in next can take advantage of low-level
+ framework change that is merged to 'master' already.
+
+ $ git rebase master ai/topic
+
+ This step is helped with Meta/git-topic.perl script to
+ identify which topic is rebaseable. There also is a
+ pre-rebase hook to make sure that topics that are already in
+ 'next' are not rebased beyond the merged commit.
+
+ - Rebuild "pu" to merge the tips of topics not in 'next'.
+
+ $ git checkout pu
+ $ git reset --hard next
+ $ git merge ai/topic ;# repeat for all remaining topics
+ $ make test
+
+ This step is helped with Meta/PU script
+
+ - Push four integration branches to a private repository at
+ k.org and run "make test" on all of them.
+
+ - Push four integration branches to /pub/scm/git/git.git at
+ k.org. This triggers its post-update hook which:
+
+ (1) runs "git pull" in $HOME/git-doc/ repository to pull
+ 'master' just pushed out;
+
+ (2) runs "make doc" in $HOME/git-doc/, install the generated
+ documentation in staging areas, which are separate
+ repositories that have html and man branches checked
+ out.
+
+ (3) runs "git commit" in the staging areas, and run "git
+ push" back to /pub/scm/git/git.git/ to update the html
+ and man branches.
+
+ (4) installs generated documentation to /pub/software/scm/git/docs/
+ to be viewed from http://www.kernel.org/
+
+ - Fetch html and man branches back from k.org, and push four
+ integration branches and the two documentation branches to
+ repo.or.cz
+
+
+Some observations to be made.
+
+ * Each topic is tested individually, and also together with
+ other topics cooking in 'next'. Until it matures, none part
+ of it is merged to 'master'.
+
+ * A topic already in 'next' can get fixes while still in
+ 'next'. Such a topic will have many merges to 'next' (in
+ other words, "git log --first-parent next" will show many
+ "Merge ai/topic to next" for the same topic.
+
+ * An unobvious fix for 'maint' is cooked in 'next' and then
+ merged to 'master' to make extra sure it is Ok and then
+ merged to 'maint'.
+
+ * Even when 'next' becomes empty (in other words, all topics
+ prove stable and are merged to 'master' and "git diff master
+ next" shows empty), it has tons of merge commits that will
+ never be in 'master'.
+
+ * In principle, "git log --first-parent master..next" should
+ show nothing but merges (in practice, there are fixup commits
+ and reverts that are not merges).
+
+ * Commits near the tip of a topic branch that are not in 'next'
+ are fair game to be discarded, replaced or rewritten.
+ Commits already merged to 'next' will not be.
+
+ * Being in the 'next' branch is not a guarantee for a topic to
+ be included in the next feature release. Being in the
+ 'master' branch typically is.
diff --git a/Documentation/howto/recover-corrupted-blob-object.txt b/Documentation/howto/recover-corrupted-blob-object.txt
new file mode 100644
index 0000000000..323b513ed0
--- /dev/null
+++ b/Documentation/howto/recover-corrupted-blob-object.txt
@@ -0,0 +1,134 @@
+Date: Fri, 9 Nov 2007 08:28:38 -0800 (PST)
+From: Linus Torvalds <torvalds@linux-foundation.org>
+Subject: corrupt object on git-gc
+Abstract: Some tricks to reconstruct blob objects in order to fix
+ a corrupted repository.
+
+On Fri, 9 Nov 2007, Yossi Leybovich wrote:
+>
+> Did not help still the repository look for this object?
+> Any one know how can I track this object and understand which file is it
+
+So exactly *because* the SHA1 hash is cryptographically secure, the hash
+itself doesn't actually tell you anything, in order to fix a corrupt
+object you basically have to find the "original source" for it.
+
+The easiest way to do that is almost always to have backups, and find the
+same object somewhere else. Backups really are a good idea, and git makes
+it pretty easy (if nothing else, just clone the repository somewhere else,
+and make sure that you do *not* use a hard-linked clone, and preferably
+not the same disk/machine).
+
+But since you don't seem to have backups right now, the good news is that
+especially with a single blob being corrupt, these things *are* somewhat
+debuggable.
+
+First off, move the corrupt object away, and *save* it. The most common
+cause of corruption so far has been memory corruption, but even so, there
+are people who would be interested in seeing the corruption - but it's
+basically impossible to judge the corruption until we can also see the
+original object, so right now the corrupt object is useless, but it's very
+interesting for the future, in the hope that you can re-create a
+non-corrupt version.
+
+So:
+
+> ib]$ mv .git/objects/4b/9458b3786228369c63936db65827de3cc06200 ../
+
+This is the right thing to do, although it's usually best to save it under
+it's full SHA1 name (you just dropped the "4b" from the result ;).
+
+Let's see what that tells us:
+
+> ib]$ git-fsck --full
+> broken link from tree 2d9263c6d23595e7cb2a21e5ebbb53655278dff8
+> to blob 4b9458b3786228369c63936db65827de3cc06200
+> missing blob 4b9458b3786228369c63936db65827de3cc06200
+
+Ok, I removed the "dangling commit" messages, because they are just
+messages about the fact that you probably have rebased etc, so they're not
+at all interesting. But what remains is still very useful. In particular,
+we now know which tree points to it!
+
+Now you can do
+
+ git ls-tree 2d9263c6d23595e7cb2a21e5ebbb53655278dff8
+
+which will show something like
+
+ 100644 blob 8d14531846b95bfa3564b58ccfb7913a034323b8 .gitignore
+ 100644 blob ebf9bf84da0aab5ed944264a5db2a65fe3a3e883 .mailmap
+ 100644 blob ca442d313d86dc67e0a2e5d584b465bd382cbf5c COPYING
+ 100644 blob ee909f2cc49e54f0799a4739d24c4cb9151ae453 CREDITS
+ 040000 tree 0f5f709c17ad89e72bdbbef6ea221c69807009f6 Documentation
+ 100644 blob 1570d248ad9237e4fa6e4d079336b9da62d9ba32 Kbuild
+ 100644 blob 1c7c229a092665b11cd46a25dbd40feeb31661d9 MAINTAINERS
+ ...
+
+and you should now have a line that looks like
+
+ 10064 blob 4b9458b3786228369c63936db65827de3cc06200 my-magic-file
+
+in the output. This already tells you a *lot* it tells you what file the
+corrupt blob came from!
+
+Now, it doesn't tell you quite enough, though: it doesn't tell what
+*version* of the file didn't get correctly written! You might be really
+lucky, and it may be the version that you already have checked out in your
+working tree, in which case fixing this problem is really simple, just do
+
+ git hash-object -w my-magic-file
+
+again, and if it outputs the missing SHA1 (4b945..) you're now all done!
+
+But that's the really lucky case, so let's assume that it was some older
+version that was broken. How do you tell which version it was?
+
+The easiest way to do it is to do
+
+ git log --raw --all --full-history -- subdirectory/my-magic-file
+
+and that will show you the whole log for that file (please realize that
+the tree you had may not be the top-level tree, so you need to figure out
+which subdirectory it was in on your own), and because you're asking for
+raw output, you'll now get something like
+
+ commit abc
+ Author:
+ Date:
+ ..
+ :100644 100644 4b9458b... newsha... M somedirectory/my-magic-file
+
+
+ commit xyz
+ Author:
+ Date:
+
+ ..
+ :100644 100644 oldsha... 4b9458b... M somedirectory/my-magic-file
+
+and this actually tells you what the *previous* and *subsequent* versions
+of that file were! So now you can look at those ("oldsha" and "newsha"
+respectively), and hopefully you have done commits often, and can
+re-create the missing my-magic-file version by looking at those older and
+newer versions!
+
+If you can do that, you can now recreate the missing object with
+
+ git hash-object -w <recreated-file>
+
+and your repository is good again!
+
+(Btw, you could have ignored the fsck, and started with doing a
+
+ git log --raw --all
+
+and just looked for the sha of the missing object (4b9458b..) in that
+whole thing. It's up to you - git does *have* a lot of information, it is
+just missing one particular blob version.
+
+Trying to recreate trees and especially commits is *much* harder. So you
+were lucky that it's a blob. It's quite possible that you can recreate the
+thing.
+
+ Linus
diff --git a/Documentation/howto/using-merge-subtree.txt b/Documentation/howto/using-merge-subtree.txt
new file mode 100644
index 0000000000..0953a50b69
--- /dev/null
+++ b/Documentation/howto/using-merge-subtree.txt
@@ -0,0 +1,75 @@
+Date: Sat, 5 Jan 2008 20:17:40 -0500
+From: Sean <seanlkml@sympatico.ca>
+To: Miklos Vajna <vmiklos@frugalware.org>
+Cc: git@vger.kernel.org
+Subject: how to use git merge -s subtree?
+Abstract: In this article, Sean demonstrates how one can use the subtree merge
+ strategy.
+Content-type: text/asciidoc
+Message-ID: <BAYC1-PASMTP12374B54BA370A1E1C6E78AE4E0@CEZ.ICE>
+
+How to use the subtree merge strategy
+=====================================
+
+There are situations where you want to include contents in your project
+from an independently developed project. You can just pull from the
+other project as long as there are no conflicting paths.
+
+The problematic case is when there are conflicting files. Potential
+candidates are Makefiles and other standard filenames. You could merge
+these files but probably you do not want to. A better solution for this
+problem can be to merge the project as its own subdirectory. This is not
+supported by the 'recursive' merge strategy, so just pulling won't work.
+
+What you want is the 'subtree' merge strategy, which helps you in such a
+situation.
+
+In this example, let's say you have the repository at `/path/to/B` (but
+it can be an URL as well, if you want). You want to merge the 'master'
+branch of that repository to the `dir-B` subdirectory in your current
+branch.
+
+Here is the command sequence you need:
+
+----------------
+$ git remote add -f Bproject /path/to/B <1>
+$ git merge -s ours --no-commit Bproject/master <2>
+$ git read-tree --prefix=dir-B/ -u Bproject/master <3>
+$ git commit -m "Merge B project as our subdirectory" <4>
+
+$ git pull -s subtree Bproject master <5>
+----------------
+<1> name the other project "Bproject", and fetch.
+<2> prepare for the later step to record the result as a merge.
+<3> read "master" branch of Bproject to the subdirectory "dir-B".
+<4> record the merge result.
+<5> maintain the result with subsequent merges using "subtree"
+
+The first four commands are used for the initial merge, while the last
+one is to merge updates from 'B project'.
+
+Comparing 'subtree' merge with submodules
+-----------------------------------------
+
+- The benefit of using subtree merge is that it requires less
+ administrative burden from the users of your repository. It works with
+ older (before Git v1.5.2) clients and you have the code right after
+ clone.
+
+- However if you use submodules then you can choose not to transfer the
+ submodule objects. This may be a problem with the subtree merge.
+
+- Also, in case you make changes to the other project, it is easier to
+ submit changes if you just use submodules.
+
+Additional tips
+---------------
+
+- If you made changes to the other project in your repository, they may
+ want to merge from your project. This is possible using subtree -- it
+ can shift up the paths in your tree and then they can merge only the
+ relevant parts of your tree.
+
+- Please note that if the other project merges from you, then it will
+ connects its history to yours, which can be something they don't want
+ to.