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-rw-r--r--Documentation/howto/maintain-git.txt277
-rw-r--r--Documentation/howto/rebase-and-edit.txt79
-rw-r--r--Documentation/howto/rebase-from-internal-branch.txt163
-rw-r--r--Documentation/howto/rebuild-from-update-hook.txt86
-rw-r--r--Documentation/howto/recover-corrupted-blob-object.txt134
-rw-r--r--Documentation/howto/revert-branch-rebase.txt193
-rw-r--r--Documentation/howto/separating-topic-branches.txt90
-rw-r--r--Documentation/howto/setup-git-server-over-http.txt277
-rw-r--r--Documentation/howto/update-hook-example.txt172
-rw-r--r--Documentation/howto/use-git-daemon.txt51
-rw-r--r--Documentation/howto/using-merge-subtree.txt75
11 files changed, 1597 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/rebase-and-edit.txt b/Documentation/howto/rebase-and-edit.txt
new file mode 100644
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--- /dev/null
+++ b/Documentation/howto/rebase-and-edit.txt
@@ -0,0 +1,79 @@
+Date: Sat, 13 Aug 2005 22:16:02 -0700 (PDT)
+From: Linus Torvalds <torvalds@osdl.org>
+To: Steve French <smfrench@austin.rr.com>
+cc: git@vger.kernel.org
+Subject: Re: sending changesets from the middle of a git tree
+Abstract: In this article, Linus demonstrates how a broken commit
+ in a sequence of commits can be removed by rewinding the head and
+ reapplying selected changes.
+
+On Sat, 13 Aug 2005, Linus Torvalds wrote:
+
+> That's correct. Same things apply: you can move a patch over, and create a
+> new one with a modified comment, but basically the _old_ commit will be
+> immutable.
+
+Let me clarify.
+
+You can entirely _drop_ old branches, so commits may be immutable, but
+nothing forces you to keep them. Of course, when you drop a commit, you'll
+always end up dropping all the commits that depended on it, and if you
+actually got somebody else to pull that commit you can't drop it from
+_their_ repository, but undoing things is not impossible.
+
+For example, let's say that you've made a mess of things: you've committed
+three commits "old->a->b->c", and you notice that "a" was broken, but you
+want to save "b" and "c". What you can do is
+
+ # Create a branch "broken" that is the current code
+ # for reference
+ git branch broken
+
+ # Reset the main branch to three parents back: this
+ # effectively undoes the three top commits
+ git reset HEAD^^^
+ git checkout -f
+
+ # Check the result visually to make sure you know what's
+ # going on
+ gitk --all
+
+ # Re-apply the two top ones from "broken"
+ #
+ # First "parent of broken" (aka b):
+ git-diff-tree -p broken^ | git-apply --index
+ git commit --reedit=broken^
+
+ # Then "top of broken" (aka c):
+ git-diff-tree -p broken | git-apply --index
+ git commit --reedit=broken
+
+and you've now re-applied (and possibly edited the comments) the two
+commits b/c, and commit "a" is basically gone (it still exists in the
+"broken" branch, of course).
+
+Finally, check out the end result again:
+
+ # Look at the new commit history
+ gitk --all
+
+to see that everything looks sensible.
+
+And then, you can just remove the broken branch if you decide you really
+don't want it:
+
+ # remove 'broken' branch
+ git branch -d broken
+
+ # Prune old objects if you're really really sure
+ git prune
+
+And yeah, I'm sure there are other ways of doing this. And as usual, the
+above is totally untested, and I just wrote it down in this email, so if
+I've done something wrong, you'll have to figure it out on your own ;)
+
+ Linus
+-
+To unsubscribe from this list: send the line "unsubscribe git" in
+the body of a message to majordomo@vger.kernel.org
+More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/howto/rebase-from-internal-branch.txt b/Documentation/howto/rebase-from-internal-branch.txt
new file mode 100644
index 0000000000..7a76045eb7
--- /dev/null
+++ b/Documentation/howto/rebase-from-internal-branch.txt
@@ -0,0 +1,163 @@
+From: Junio C Hamano <junkio@cox.net>
+To: git@vger.kernel.org
+Cc: Petr Baudis <pasky@suse.cz>, Linus Torvalds <torvalds@osdl.org>
+Subject: Re: sending changesets from the middle of a git tree
+Date: Sun, 14 Aug 2005 18:37:39 -0700
+Abstract: In this article, JC talks about how he rebases the
+ public "pu" branch using the core GIT tools when he updates
+ the "master" branch, and how "rebase" works. Also discussed
+ is how this applies to individual developers who sends patches
+ upstream.
+
+Petr Baudis <pasky@suse.cz> writes:
+
+> Dear diary, on Sun, Aug 14, 2005 at 09:57:13AM CEST, I got a letter
+> where Junio C Hamano <junkio@cox.net> told me that...
+>> Linus Torvalds <torvalds@osdl.org> writes:
+>>
+>> > Junio, maybe you want to talk about how you move patches from your "pu"
+>> > branch to the real branches.
+>>
+> Actually, wouldn't this be also precisely for what StGIT is intended to?
+
+Exactly my feeling. I was sort of waiting for Catalin to speak
+up. With its basing philosophical ancestry on quilt, this is
+the kind of task StGIT is designed to do.
+
+I just have done a simpler one, this time using only the core
+GIT tools.
+
+I had a handful commits that were ahead of master in pu, and I
+wanted to add some documentation bypassing my usual habit of
+placing new things in pu first. At the beginning, the commit
+ancestry graph looked like this:
+
+ *"pu" head
+ master --> #1 --> #2 --> #3
+
+So I started from master, made a bunch of edits, and committed:
+
+ $ git checkout master
+ $ cd Documentation; ed git.txt ...
+ $ cd ..; git add Documentation/*.txt
+ $ git commit -s
+
+After the commit, the ancestry graph would look like this:
+
+ *"pu" head
+ master^ --> #1 --> #2 --> #3
+ \
+ \---> master
+
+The old master is now master^ (the first parent of the master).
+The new master commit holds my documentation updates.
+
+Now I have to deal with "pu" branch.
+
+This is the kind of situation I used to have all the time when
+Linus was the maintainer and I was a contributor, when you look
+at "master" branch being the "maintainer" branch, and "pu"
+branch being the "contributor" branch. Your work started at the
+tip of the "maintainer" branch some time ago, you made a lot of
+progress in the meantime, and now the maintainer branch has some
+other commits you do not have yet. And "git rebase" was written
+with the explicit purpose of helping to maintain branches like
+"pu". You _could_ merge master to pu and keep going, but if you
+eventually want to cherrypick and merge some but not necessarily
+all changes back to the master branch, it often makes later
+operations for _you_ easier if you rebase (i.e. carry forward
+your changes) "pu" rather than merge. So I ran "git rebase":
+
+ $ git checkout pu
+ $ git rebase master pu
+
+What this does is to pick all the commits since the current
+branch (note that I now am on "pu" branch) forked from the
+master branch, and forward port these changes.
+
+ master^ --> #1 --> #2 --> #3
+ \ *"pu" head
+ \---> master --> #1' --> #2' --> #3'
+
+The diff between master^ and #1 is applied to master and
+committed to create #1' commit with the commit information (log,
+author and date) taken from commit #1. On top of that #2' and #3'
+commits are made similarly out of #2 and #3 commits.
+
+Old #3 is not recorded in any of the .git/refs/heads/ file
+anymore, so after doing this you will have dangling commit if
+you ran fsck-cache, which is normal. After testing "pu", you
+can run "git prune" to get rid of those original three commits.
+
+While I am talking about "git rebase", I should talk about how
+to do cherrypicking using only the core GIT tools.
+
+Let's go back to the earlier picture, with different labels.
+
+You, as an individual developer, cloned upstream repository and
+made a couple of commits on top of it.
+
+ *your "master" head
+ upstream --> #1 --> #2 --> #3
+
+You would want changes #2 and #3 incorporated in the upstream,
+while you feel that #1 may need further improvements. So you
+prepare #2 and #3 for e-mail submission.
+
+ $ git format-patch master^^ master
+
+This creates two files, 0001-XXXX.patch and 0002-XXXX.patch. Send
+them out "To: " your project maintainer and "Cc: " your mailing
+list. You could use contributed script git-send-email if
+your host has necessary perl modules for this, but your usual
+MUA would do as long as it does not corrupt whitespaces in the
+patch.
+
+Then you would wait, and you find out that the upstream picked
+up your changes, along with other changes.
+
+ where *your "master" head
+ upstream --> #1 --> #2 --> #3
+ used \
+ to be \--> #A --> #2' --> #3' --> #B --> #C
+ *upstream head
+
+The two commits #2' and #3' in the above picture record the same
+changes your e-mail submission for #2 and #3 contained, but
+probably with the new sign-off line added by the upstream
+maintainer and definitely with different committer and ancestry
+information, they are different objects from #2 and #3 commits.
+
+You fetch from upstream, but not merge.
+
+ $ git fetch upstream
+
+This leaves the updated upstream head in .git/FETCH_HEAD but
+does not touch your .git/HEAD nor .git/refs/heads/master.
+You run "git rebase" now.
+
+ $ git rebase FETCH_HEAD master
+
+Earlier, I said that rebase applies all the commits from your
+branch on top of the upstream head. Well, I lied. "git rebase"
+is a bit smarter than that and notices that #2 and #3 need not
+be applied, so it only applies #1. The commit ancestry graph
+becomes something like this:
+
+ where *your old "master" head
+ upstream --> #1 --> #2 --> #3
+ used \ your new "master" head*
+ to be \--> #A --> #2' --> #3' --> #B --> #C --> #1'
+ *upstream
+ head
+
+Again, "git prune" would discard the disused commits #1-#3 and
+you continue on starting from the new "master" head, which is
+the #1' commit.
+
+-jc
+
+-
+To unsubscribe from this list: send the line "unsubscribe git" in
+the body of a message to majordomo@vger.kernel.org
+More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/Documentation/howto/rebuild-from-update-hook.txt b/Documentation/howto/rebuild-from-update-hook.txt
new file mode 100644
index 0000000000..8d55dfbfae
--- /dev/null
+++ b/Documentation/howto/rebuild-from-update-hook.txt
@@ -0,0 +1,86 @@
+Subject: [HOWTO] Using post-update hook
+Message-ID: <7vy86o6usx.fsf@assigned-by-dhcp.cox.net>
+From: Junio C Hamano <junkio@cox.net>
+Date: Fri, 26 Aug 2005 18:19:10 -0700
+Abstract: In this how-to article, JC talks about how he
+ uses the post-update hook to automate git documentation page
+ shown at http://www.kernel.org/pub/software/scm/git/docs/.
+
+The pages under http://www.kernel.org/pub/software/scm/git/docs/
+are built from Documentation/ directory of the git.git project
+and needed to be kept up-to-date. The www.kernel.org/ servers
+are mirrored and I was told that the origin of the mirror is on
+the machine $some.kernel.org, on which I was given an account
+when I took over git maintainership from Linus.
+
+The directories relevant to this how-to are these two:
+
+ /pub/scm/git/git.git/ The public git repository.
+ /pub/software/scm/git/docs/ The HTML documentation page.
+
+So I made a repository to generate the documentation under my
+home directory over there.
+
+ $ cd
+ $ mkdir doc-git && cd doc-git
+ $ git clone /pub/scm/git/git.git/ docgen
+
+What needs to happen is to update the $HOME/doc-git/docgen/
+working tree, build HTML docs there and install the result in
+/pub/software/scm/git/docs/ directory. So I wrote a little
+script:
+
+ $ cat >dododoc.sh <<\EOF
+ #!/bin/sh
+ cd $HOME/doc-git/docgen || exit
+
+ unset GIT_DIR
+
+ git pull /pub/scm/git/git.git/ master &&
+ cd Documentation &&
+ make install-webdoc
+ EOF
+
+Initially I used to run this by hand whenever I push into the
+public git repository. Then I did a cron job that ran twice a
+day. The current round uses the post-update hook mechanism,
+like this:
+
+ $ cat >/pub/scm/git/git.git/hooks/post-update <<\EOF
+ #!/bin/sh
+ #
+ # An example hook script to prepare a packed repository for use over
+ # dumb transports.
+ #
+ # To enable this hook, make this file executable by "chmod +x post-update".
+
+ case " $* " in
+ *' refs/heads/master '*)
+ echo $HOME/doc-git/dododoc.sh | at now
+ ;;
+ esac
+ exec git-update-server-info
+ EOF
+ $ chmod +x /pub/scm/git/git.git/hooks/post-update
+
+There are four things worth mentioning:
+
+ - The update-hook is run after the repository accepts a "git
+ push", under my user privilege. It is given the full names
+ of refs that have been updated as arguments. My post-update
+ runs the dododoc.sh script only when the master head is
+ updated.
+
+ - When update-hook is run, GIT_DIR is set to '.' by the calling
+ receive-pack. This is inherited by the dododoc.sh run via
+ the "at" command, and needs to be unset; otherwise, "git
+ pull" it does into $HOME/doc-git/docgen/ repository would not
+ work correctly.
+
+ - The stdout of update hook script is not connected to git
+ push; I run the heavy part of the command inside "at", to
+ receive the execution report via e-mail.
+
+ - This is still crude and does not protect against simultaneous
+ make invocations stomping on each other. I would need to add
+ some locking mechanism for this.
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/revert-branch-rebase.txt b/Documentation/howto/revert-branch-rebase.txt
new file mode 100644
index 0000000000..865a666324
--- /dev/null
+++ b/Documentation/howto/revert-branch-rebase.txt
@@ -0,0 +1,193 @@
+From: Junio C Hamano <junkio@cox.net>
+To: git@vger.kernel.org
+Subject: [HOWTO] Reverting an existing commit
+Abstract: In this article, JC gives a small real-life example of using
+ 'git revert' command, and using a temporary branch and tag for safety
+ and easier sanity checking.
+Date: Mon, 29 Aug 2005 21:39:02 -0700
+Content-type: text/asciidoc
+Message-ID: <7voe7g3uop.fsf@assigned-by-dhcp.cox.net>
+
+Reverting an existing commit
+============================
+
+One of the changes I pulled into the 'master' branch turns out to
+break building GIT with GCC 2.95. While they were well intentioned
+portability fixes, keeping things working with gcc-2.95 was also
+important. Here is what I did to revert the change in the 'master'
+branch and to adjust the 'pu' branch, using core GIT tools and
+barebone Porcelain.
+
+First, prepare a throw-away branch in case I screw things up.
+
+------------------------------------------------
+$ git checkout -b revert-c99 master
+------------------------------------------------
+
+Now I am on the 'revert-c99' branch. Let's figure out which commit to
+revert. I happen to know that the top of the 'master' branch is a
+merge, and its second parent (i.e. foreign commit I merged from) has
+the change I would want to undo. Further I happen to know that that
+merge introduced 5 commits or so:
+
+------------------------------------------------
+$ git show-branch --more=4 master master^2 | head
+* [master] Merge refs/heads/portable from http://www.cs.berkeley....
+ ! [master^2] Replace C99 array initializers with code.
+--
+- [master] Merge refs/heads/portable from http://www.cs.berkeley....
+*+ [master^2] Replace C99 array initializers with code.
+*+ [master^2~1] Replace unsetenv() and setenv() with older putenv().
+*+ [master^2~2] Include sys/time.h in daemon.c.
+*+ [master^2~3] Fix ?: statements.
+*+ [master^2~4] Replace zero-length array decls with [].
+* [master~1] tutorial note about git branch
+------------------------------------------------
+
+The '--more=4' above means "after we reach the merge base of refs,
+show until we display four more common commits". That last commit
+would have been where the "portable" branch was forked from the main
+git.git repository, so this would show everything on both branches
+since then. I just limited the output to the first handful using
+'head'.
+
+Now I know 'master^2~4' (pronounce it as "find the second parent of
+the 'master', and then go four generations back following the first
+parent") is the one I would want to revert. Since I also want to say
+why I am reverting it, the '-n' flag is given to 'git revert'. This
+prevents it from actually making a commit, and instead 'git revert'
+leaves the commit log message it wanted to use in '.msg' file:
+
+------------------------------------------------
+$ git revert -n master^2~4
+$ cat .msg
+Revert "Replace zero-length array decls with []."
+
+This reverts 6c5f9baa3bc0d63e141e0afc23110205379905a4 commit.
+$ git diff HEAD ;# to make sure what we are reverting makes sense.
+$ make CC=gcc-2.95 clean test ;# make sure it fixed the breakage.
+$ make clean test ;# make sure it did not cause other breakage.
+------------------------------------------------
+
+The reverted change makes sense (from reading the 'diff' output), does
+fix the problem (from 'make CC=gcc-2.95' test), and does not cause new
+breakage (from the last 'make test'). I'm ready to commit:
+
+------------------------------------------------
+$ git commit -a -s ;# read .msg into the log,
+ # and explain why I am reverting.
+------------------------------------------------
+
+I could have screwed up in any of the above steps, but in the worst
+case I could just have done 'git checkout master' to start over.
+Fortunately I did not have to; what I have in the current branch
+'revert-c99' is what I want. So merge that back into 'master':
+
+------------------------------------------------
+$ git checkout master
+$ git merge revert-c99 ;# this should be a fast forward
+Updating from 10d781b9caa4f71495c7b34963bef137216f86a8 to e3a693c...
+ cache.h | 8 ++++----
+ commit.c | 2 +-
+ ls-files.c | 2 +-
+ receive-pack.c | 2 +-
+ server-info.c | 2 +-
+ 5 files changed, 8 insertions(+), 8 deletions(-)
+------------------------------------------------
+
+There is no need to redo the test at this point. We fast forwarded
+and we know 'master' matches 'revert-c99' exactly. In fact:
+
+------------------------------------------------
+$ git diff master..revert-c99
+------------------------------------------------
+
+says nothing.
+
+Then we rebase the 'pu' branch as usual.
+
+------------------------------------------------
+$ git checkout pu
+$ git tag pu-anchor pu
+$ git rebase master
+* Applying: Redo "revert" using three-way merge machinery.
+First trying simple merge strategy to cherry-pick.
+Finished one cherry-pick.
+* Applying: Remove git-apply-patch-script.
+First trying simple merge strategy to cherry-pick.
+Simple cherry-pick fails; trying Automatic cherry-pick.
+Removing Documentation/git-apply-patch-script.txt
+Removing git-apply-patch-script
+Finished one cherry-pick.
+* Applying: Document "git cherry-pick" and "git revert"
+First trying simple merge strategy to cherry-pick.
+Finished one cherry-pick.
+* Applying: mailinfo and applymbox updates
+First trying simple merge strategy to cherry-pick.
+Finished one cherry-pick.
+* Applying: Show commits in topo order and name all commits.
+First trying simple merge strategy to cherry-pick.
+Finished one cherry-pick.
+* Applying: More documentation updates.
+First trying simple merge strategy to cherry-pick.
+Finished one cherry-pick.
+------------------------------------------------
+
+The temporary tag 'pu-anchor' is me just being careful, in case 'git
+rebase' screws up. After this, I can do these for sanity check:
+
+------------------------------------------------
+$ git diff pu-anchor..pu ;# make sure we got the master fix.
+$ make CC=gcc-2.95 clean test ;# make sure it fixed the breakage.
+$ make clean test ;# make sure it did not cause other breakage.
+------------------------------------------------
+
+Everything is in the good order. I do not need the temporary branch
+nor tag anymore, so remove them:
+
+------------------------------------------------
+$ rm -f .git/refs/tags/pu-anchor
+$ git branch -d revert-c99
+------------------------------------------------
+
+It was an emergency fix, so we might as well merge it into the
+'release candidate' branch, although I expect the next release would
+be some days off:
+
+------------------------------------------------
+$ git checkout rc
+$ git pull . master
+Packing 0 objects
+Unpacking 0 objects
+
+* committish: e3a693c... refs/heads/master from .
+Trying to merge e3a693c... into 8c1f5f0... using 10d781b...
+Committed merge 7fb9b7262a1d1e0a47bbfdcbbcf50ce0635d3f8f
+ cache.h | 8 ++++----
+ commit.c | 2 +-
+ ls-files.c | 2 +-
+ receive-pack.c | 2 +-
+ server-info.c | 2 +-
+ 5 files changed, 8 insertions(+), 8 deletions(-)
+------------------------------------------------
+
+And the final repository status looks like this:
+
+------------------------------------------------
+$ git show-branch --more=1 master pu rc
+! [master] Revert "Replace zero-length array decls with []."
+ ! [pu] git-repack: Add option to repack all objects.
+ * [rc] Merge refs/heads/master from .
+---
+ + [pu] git-repack: Add option to repack all objects.
+ + [pu~1] More documentation updates.
+ + [pu~2] Show commits in topo order and name all commits.
+ + [pu~3] mailinfo and applymbox updates
+ + [pu~4] Document "git cherry-pick" and "git revert"
+ + [pu~5] Remove git-apply-patch-script.
+ + [pu~6] Redo "revert" using three-way merge machinery.
+ - [rc] Merge refs/heads/master from .
+++* [master] Revert "Replace zero-length array decls with []."
+ - [rc~1] Merge refs/heads/master from .
+... [master~1] Merge refs/heads/portable from http://www.cs.berkeley....
+------------------------------------------------
diff --git a/Documentation/howto/separating-topic-branches.txt b/Documentation/howto/separating-topic-branches.txt
new file mode 100644
index 0000000000..0d73b31224
--- /dev/null
+++ b/Documentation/howto/separating-topic-branches.txt
@@ -0,0 +1,90 @@
+From: Junio C Hamano <junkio@cox.net>
+Subject: Separating topic branches
+Abstract: In this article, JC describes how to separate topic branches.
+
+This text was originally a footnote to a discussion about the
+behaviour of the git diff commands.
+
+Often I find myself doing that [running diff against something other
+than HEAD] while rewriting messy development history. For example, I
+start doing some work without knowing exactly where it leads, and end
+up with a history like this:
+
+ "master"
+ o---o
+ \ "topic"
+ o---o---o---o---o---o
+
+At this point, "topic" contains something I know I want, but it
+contains two concepts that turned out to be completely independent.
+And often, one topic component is larger than the other. It may
+contain more than two topics.
+
+In order to rewrite this mess to be more manageable, I would first do
+"diff master..topic", to extract the changes into a single patch, start
+picking pieces from it to get logically self-contained units, and
+start building on top of "master":
+
+ $ git diff master..topic >P.diff
+ $ git checkout -b topicA master
+ ... pick and apply pieces from P.diff to build
+ ... commits on topicA branch.
+
+ o---o---o
+ / "topicA"
+ o---o"master"
+ \ "topic"
+ o---o---o---o---o---o
+
+Before doing each commit on "topicA" HEAD, I run "diff HEAD"
+before update-index the affected paths, or "diff --cached HEAD"
+after. Also I would run "diff --cached master" to make sure
+that the changes are only the ones related to "topicA". Usually
+I do this for smaller topics first.
+
+After that, I'd do the remainder of the original "topic", but
+for that, I do not start from the patchfile I extracted by
+comparing "master" and "topic" I used initially. Still on
+"topicA", I extract "diff topic", and use it to rebuild the
+other topic:
+
+ $ git diff -R topic >P.diff ;# --cached also would work fine
+ $ git checkout -b topicB master
+ ... pick and apply pieces from P.diff to build
+ ... commits on topicB branch.
+
+ "topicB"
+ o---o---o---o---o
+ /
+ /o---o---o
+ |/ "topicA"
+ o---o"master"
+ \ "topic"
+ o---o---o---o---o---o
+
+After I am done, I'd try a pretend-merge between "topicA" and
+"topicB" in order to make sure I have not missed anything:
+
+ $ git pull . topicA ;# merge it into current "topicB"
+ $ git diff topic
+ "topicB"
+ o---o---o---o---o---* (pretend merge)
+ / /
+ /o---o---o----------'
+ |/ "topicA"
+ o---o"master"
+ \ "topic"
+ o---o---o---o---o---o
+
+The last diff better not to show anything other than cleanups
+for crufts. Then I can finally clean things up:
+
+ $ git branch -D topic
+ $ git reset --hard HEAD^ ;# nuke pretend merge
+
+ "topicB"
+ o---o---o---o---o
+ /
+ /o---o---o
+ |/ "topicA"
+ o---o"master"
diff --git a/Documentation/howto/setup-git-server-over-http.txt b/Documentation/howto/setup-git-server-over-http.txt
new file mode 100644
index 0000000000..b7d09c1ec6
--- /dev/null
+++ b/Documentation/howto/setup-git-server-over-http.txt
@@ -0,0 +1,277 @@
+From: Rutger Nijlunsing <rutger@nospam.com>
+Subject: Setting up a git repository which can be pushed into and pulled from over HTTP(S).
+Date: Thu, 10 Aug 2006 22:00:26 +0200
+
+Since Apache is one of those packages people like to compile
+themselves while others prefer the bureaucrat's dream Debian, it is
+impossible to give guidelines which will work for everyone. Just send
+some feedback to the mailing list at git@vger.kernel.org to get this
+document tailored to your favorite distro.
+
+
+What's needed:
+
+- Have an Apache web-server
+
+ On Debian:
+ $ apt-get install apache2
+ To get apache2 by default started,
+ edit /etc/default/apache2 and set NO_START=0
+
+- can edit the configuration of it.
+
+ This could be found under /etc/httpd, or refer to your Apache documentation.
+
+ On Debian: this means being able to edit files under /etc/apache2
+
+- can restart it.
+
+ 'apachectl --graceful' might do. If it doesn't, just stop and
+ restart apache. Be warning that active connections to your server
+ might be aborted by this.
+
+ On Debian:
+ $ /etc/init.d/apache2 restart
+ or
+ $ /etc/init.d/apache2 force-reload
+ (which seems to do the same)
+ This adds symlinks from the /etc/apache2/mods-enabled to
+ /etc/apache2/mods-available.
+
+- have permissions to chown a directory
+
+- have git installed on the client, and
+
+- either have git installed on the server or have a webdav client on
+ the client.
+
+In effect, this means you're going to be root, or that you're using a
+preconfigured WebDAV server.
+
+
+Step 1: setup a bare GIT repository
+-----------------------------------
+
+At the time of writing, git-http-push cannot remotely create a GIT
+repository. So we have to do that at the server side with git. Another
+option is to generate an empty bare repository at the client and copy
+it to the server with a WebDAV client (which is the only option if Git
+is not installed on the server).
+
+Create the directory under the DocumentRoot of the directories served
+by Apache. As an example we take /usr/local/apache2, but try "grep
+DocumentRoot /where/ever/httpd.conf" to find your root:
+
+ $ cd /usr/local/apache/htdocs
+ $ mkdir my-new-repo.git
+
+ On Debian:
+
+ $ cd /var/www
+ $ mkdir my-new-repo.git
+
+
+Initialize a bare repository
+
+ $ cd my-new-repo.git
+ $ git --bare init
+
+
+Change the ownership to your web-server's credentials. Use "grep ^User
+httpd.conf" and "grep ^Group httpd.conf" to find out:
+
+ $ chown -R www.www .
+
+ On Debian:
+
+ $ chown -R www-data.www-data .
+
+
+If you do not know which user Apache runs as, you can alternatively do
+a "chmod -R a+w .", inspect the files which are created later on, and
+set the permissions appropriately.
+
+Restart apache2, and check whether http://server/my-new-repo.git gives
+a directory listing. If not, check whether apache started up
+successfully.
+
+
+Step 2: enable DAV on this repository
+-------------------------------------
+
+First make sure the dav_module is loaded. For this, insert in httpd.conf:
+
+ LoadModule dav_module libexec/httpd/libdav.so
+ AddModule mod_dav.c
+
+Also make sure that this line exists which is the file used for
+locking DAV operations:
+
+ DAVLockDB "/usr/local/apache2/temp/DAV.lock"
+
+ On Debian these steps can be performed with:
+
+ Enable the dav and dav_fs modules of apache:
+ $ a2enmod dav_fs
+ (just to be sure. dav_fs might be unneeded, I don't know)
+ $ a2enmod dav
+ The DAV lock is located in /etc/apache2/mods-available/dav_fs.conf:
+ DAVLockDB /var/lock/apache2/DAVLock
+
+Of course, it can point somewhere else, but the string is actually just a
+prefix in some Apache configurations, and therefore the _directory_ has to
+be writable by the user Apache runs as.
+
+Then, add something like this to your httpd.conf
+
+ <Location /my-new-repo.git>
+ DAV on
+ AuthType Basic
+ AuthName "Git"
+ AuthUserFile /usr/local/apache2/conf/passwd.git
+ Require valid-user
+ </Location>
+
+ On Debian:
+ Create (or add to) /etc/apache2/conf.d/git.conf :
+
+ <Location /my-new-repo.git>
+ DAV on
+ AuthType Basic
+ AuthName "Git"
+ AuthUserFile /etc/apache2/passwd.git
+ Require valid-user
+ </Location>
+
+ Debian automatically reads all files under /etc/apach2/conf.d.
+
+The password file can be somewhere else, but it has to be readable by
+Apache and preferably not readable by the world.
+
+Create this file by
+ $ htpasswd -c /usr/local/apache2/conf/passwd.git <user>
+
+ On Debian:
+ $ htpasswd -c /etc/apache2/passwd.git <user>
+
+You will be asked a password, and the file is created. Subsequent calls
+to htpasswd should omit the '-c' option, since you want to append to the
+existing file.
+
+You need to restart Apache.
+
+Now go to http://<username>@<servername>/my-new-repo.git in your
+browser to check whether it asks for a password and accepts the right
+password.
+
+On Debian:
+
+ To test the WebDAV part, do:
+
+ $ apt-get install litmus
+ $ litmus http://<servername>/my-new-repo.git <username> <password>
+
+ Most tests should pass.
+
+A command line tool to test WebDAV is cadaver. If you prefer GUIs, for
+example, konqueror can open WebDAV URLs as "webdav://..." or
+"webdavs://...".
+
+If you're into Windows, from XP onwards Internet Explorer supports
+WebDAV. For this, do Internet Explorer -> Open Location ->
+http://<servername>/my-new-repo.git [x] Open as webfolder -> login .
+
+
+Step 3: setup the client
+------------------------
+
+Make sure that you have HTTP support, i.e. your git was built with
+curl (version more recent than 7.10). The command 'git http-push' with
+no argument should display a usage message.
+
+Then, add the following to your $HOME/.netrc (you can do without, but will be
+asked to input your password a _lot_ of times):
+
+ machine <servername>
+ login <username>
+ password <password>
+
+...and set permissions:
+ chmod 600 ~/.netrc
+
+If you want to access the web-server by its IP, you have to type that in,
+instead of the server name.
+
+To check whether all is OK, do:
+
+ curl --netrc --location -v http://<username>@<servername>/my-new-repo.git/HEAD
+
+...this should give something like 'ref: refs/heads/master', which is
+the content of the file HEAD on the server.
+
+Now, add the remote in your existing repository which contains the project
+you want to export:
+
+ $ git-config remote.upload.url \
+ http://<username>@<servername>/my-new-repo.git/
+
+It is important to put the last '/'; Without it, the server will send
+a redirect which git-http-push does not (yet) understand, and git-http-push
+will repeat the request infinitely.
+
+
+Step 4: make the initial push
+-----------------------------
+
+From your client repository, do
+
+ $ git push upload master
+
+This pushes branch 'master' (which is assumed to be the branch you
+want to export) to repository called 'upload', which we previously
+defined with git-config.
+
+
+Using a proxy:
+--------------
+
+If you have to access the WebDAV server from behind an HTTP(S) proxy,
+set the variable 'all_proxy' to 'http://proxy-host.com:port', or
+'http://login-on-proxy:passwd-on-proxy@proxy-host.com:port'. See 'man
+curl' for details.
+
+
+Troubleshooting:
+----------------
+
+If git-http-push says
+
+ Error: no DAV locking support on remote repo http://...
+
+then it means the web-server did not accept your authentication. Make sure
+that the user name and password matches in httpd.conf, .netrc and the URL
+you are uploading to.
+
+If git-http-push shows you an error (22/502) when trying to MOVE a blob,
+it means that your web-server somehow does not recognize its name in the
+request; This can happen when you start Apache, but then disable the
+network interface. A simple restart of Apache helps.
+
+Errors like (22/502) are of format (curl error code/http error
+code). So (22/404) means something like 'not found' at the server.
+
+Reading /usr/local/apache2/logs/error_log is often helpful.
+
+ On Debian: Read /var/log/apache2/error.log instead.
+
+If you access HTTPS locations, git may fail verifying the SSL
+certificate (this is return code 60). Setting http.sslVerify=false can
+help diagnosing the problem, but removes security checks.
+
+
+Debian References: http://www.debian-administration.org/articles/285
+
+Authors
+ Johannes Schindelin <Johannes.Schindelin@gmx.de>
+ Rutger Nijlunsing <git@wingding.demon.nl>
+ Matthieu Moy <Matthieu.Moy@imag.fr>
diff --git a/Documentation/howto/update-hook-example.txt b/Documentation/howto/update-hook-example.txt
new file mode 100644
index 0000000000..88765b5575
--- /dev/null
+++ b/Documentation/howto/update-hook-example.txt
@@ -0,0 +1,172 @@
+From: Junio C Hamano <junkio@cox.net> and Carl Baldwin <cnb@fc.hp.com>
+Subject: control access to branches.
+Date: Thu, 17 Nov 2005 23:55:32 -0800
+Message-ID: <7vfypumlu3.fsf@assigned-by-dhcp.cox.net>
+Abstract: An example hooks/update script is presented to
+ implement repository maintenance policies, such as who can push
+ into which branch and who can make a tag.
+
+When your developer runs git-push into the repository,
+git-receive-pack is run (either locally or over ssh) as that
+developer, so is hooks/update script. Quoting from the relevant
+section of the documentation:
+
+ Before each ref is updated, if $GIT_DIR/hooks/update file exists
+ and executable, it is called with three parameters:
+
+ $GIT_DIR/hooks/update refname sha1-old sha1-new
+
+ The refname parameter is relative to $GIT_DIR; e.g. for the
+ master head this is "refs/heads/master". Two sha1 are the
+ object names for the refname before and after the update. Note
+ that the hook is called before the refname is updated, so either
+ sha1-old is 0{40} (meaning there is no such ref yet), or it
+ should match what is recorded in refname.
+
+So if your policy is (1) always require fast-forward push
+(i.e. never allow "git-push repo +branch:branch"), (2) you
+have a list of users allowed to update each branch, and (3) you
+do not let tags to be overwritten, then you can use something
+like this as your hooks/update script.
+
+[jc: editorial note. This is a much improved version by Carl
+since I posted the original outline]
+
+-- >8 -- beginning of script -- >8 --
+
+#!/bin/bash
+
+umask 002
+
+# If you are having trouble with this access control hook script
+# you can try setting this to true. It will tell you exactly
+# why a user is being allowed/denied access.
+
+verbose=false
+
+# Default shell globbing messes things up downstream
+GLOBIGNORE=*
+
+function grant {
+ $verbose && echo >&2 "-Grant- $1"
+ echo grant
+ exit 0
+}
+
+function deny {
+ $verbose && echo >&2 "-Deny- $1"
+ echo deny
+ exit 1
+}
+
+function info {
+ $verbose && echo >&2 "-Info- $1"
+}
+
+# Implement generic branch and tag policies.
+# - Tags should not be updated once created.
+# - Branches should only be fast-forwarded.
+case "$1" in
+ refs/tags/*)
+ [ -f "$GIT_DIR/$1" ] &&
+ deny >/dev/null "You can't overwrite an existing tag"
+ ;;
+ refs/heads/*)
+ # No rebasing or rewinding
+ if expr "$2" : '0*$' >/dev/null; then
+ info "The branch '$1' is new..."
+ else
+ # updating -- make sure it is a fast forward
+ mb=$(git-merge-base "$2" "$3")
+ case "$mb,$2" in
+ "$2,$mb") info "Update is fast-forward" ;;
+ *) deny >/dev/null "This is not a fast-forward update." ;;
+ esac
+ fi
+ ;;
+ *)
+ deny >/dev/null \
+ "Branch is not under refs/heads or refs/tags. What are you trying to do?"
+ ;;
+esac
+
+# Implement per-branch controls based on username
+allowed_users_file=$GIT_DIR/info/allowed-users
+username=$(id -u -n)
+info "The user is: '$username'"
+
+if [ -f "$allowed_users_file" ]; then
+ rc=$(cat $allowed_users_file | grep -v '^#' | grep -v '^$' |
+ while read head_pattern user_patterns; do
+ matchlen=$(expr "$1" : "$head_pattern")
+ if [ "$matchlen" == "${#1}" ]; then
+ info "Found matching head pattern: '$head_pattern'"
+ for user_pattern in $user_patterns; do
+ info "Checking user: '$username' against pattern: '$user_pattern'"
+ matchlen=$(expr "$username" : "$user_pattern")
+ if [ "$matchlen" == "${#username}" ]; then
+ grant "Allowing user: '$username' with pattern: '$user_pattern'"
+ fi
+ done
+ deny "The user is not in the access list for this branch"
+ fi
+ done
+ )
+ case "$rc" in
+ grant) grant >/dev/null "Granting access based on $allowed_users_file" ;;
+ deny) deny >/dev/null "Denying access based on $allowed_users_file" ;;
+ *) ;;
+ esac
+fi
+
+allowed_groups_file=$GIT_DIR/info/allowed-groups
+groups=$(id -G -n)
+info "The user belongs to the following groups:"
+info "'$groups'"
+
+if [ -f "$allowed_groups_file" ]; then
+ rc=$(cat $allowed_groups_file | grep -v '^#' | grep -v '^$' |
+ while read head_pattern group_patterns; do
+ matchlen=$(expr "$1" : "$head_pattern")
+ if [ "$matchlen" == "${#1}" ]; then
+ info "Found matching head pattern: '$head_pattern'"
+ for group_pattern in $group_patterns; do
+ for groupname in $groups; do
+ info "Checking group: '$groupname' against pattern: '$group_pattern'"
+ matchlen=$(expr "$groupname" : "$group_pattern")
+ if [ "$matchlen" == "${#groupname}" ]; then
+ grant "Allowing group: '$groupname' with pattern: '$group_pattern'"
+ fi
+ done
+ done
+ deny "None of the user's groups are in the access list for this branch"
+ fi
+ done
+ )
+ case "$rc" in
+ grant) grant >/dev/null "Granting access based on $allowed_groups_file" ;;
+ deny) deny >/dev/null "Denying access based on $allowed_groups_file" ;;
+ *) ;;
+ esac
+fi
+
+deny >/dev/null "There are no more rules to check. Denying access"
+
+-- >8 -- end of script -- >8 --
+
+This uses two files, $GIT_DIR/info/allowed-users and
+allowed-groups, to describe which heads can be pushed into by
+whom. The format of each file would look like this:
+
+ refs/heads/master junio
+ refs/heads/cogito$ pasky
+ refs/heads/bw/.* linus
+ refs/heads/tmp/.* .*
+ refs/tags/v[0-9].* junio
+
+With this, Linus can push or create "bw/penguin" or "bw/zebra"
+or "bw/panda" branches, Pasky can do only "cogito", and JC can
+do master branch and make versioned tags. And anybody can do
+tmp/blah branches.
+
+------------
diff --git a/Documentation/howto/use-git-daemon.txt b/Documentation/howto/use-git-daemon.txt
new file mode 100644
index 0000000000..4e2f75cb61
--- /dev/null
+++ b/Documentation/howto/use-git-daemon.txt
@@ -0,0 +1,51 @@
+How to use git-daemon
+
+Git can be run in inetd mode and in stand alone mode. But all you want is
+let a coworker pull from you, and therefore need to set up a git server
+real quick, right?
+
+Note that git-daemon is not really chatty at the moment, especially when
+things do not go according to plan (e.g. a socket could not be bound).
+
+Another word of warning: if you run
+
+ $ git ls-remote git://127.0.0.1/rule-the-world.git
+
+and you see a message like
+
+ fatal: The remote end hung up unexpectedly
+
+it only means that _something_ went wrong. To find out _what_ went wrong,
+you have to ask the server. (Git refuses to be more precise for your
+security only. Take off your shoes now. You have any coins in your pockets?
+Sorry, not allowed -- who knows what you planned to do with them?)
+
+With these two caveats, let's see an example:
+
+ $ git daemon --reuseaddr --verbose --base-path=/home/gitte/git \
+ --export-all -- /home/gitte/git/rule-the-world.git
+
+(Of course, unless your user name is `gitte` _and_ your repository is in
+~/rule-the-world.git, you have to adjust the paths. If your repository is
+not bare, be aware that you have to type the path to the .git directory!)
+
+This invocation tries to reuse the address if it is already taken
+(this can save you some debugging, because otherwise killing and restarting
+git-daemon could just silently fail to bind to a socket).
+
+Also, it is (relatively) verbose when somebody actually connects to it.
+It also sets the base path, which means that all the projects which can be
+accessed using this daemon have to reside in or under that path.
+
+The option `--export-all` just means that you _don't_ have to create a
+file named `git-daemon-export-ok` in each exported repository. (Otherwise,
+git-daemon would complain loudly, and refuse to cooperate.)
+
+Last of all, the repository which should be exported is specified. It is
+a good practice to put the paths after a "--" separator.
+
+Now, test your daemon with
+
+ $ git ls-remote git://127.0.0.1/rule-the-world.git
+
+If this does not work, find out why, and submit a patch to this document.
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.