2 Consistent formatting of this file is achieved with:
3 perl ./Porting/podtidy pod/perlrepository.pod
7 perlrepository - Using the Perl source repository
11 All of Perl's source code is kept centrally in a Git repository at
12 I<perl5.git.perl.org>. The repository contains many Perl revisions from
13 Perl 1 onwards and all the revisions from Perforce, the version control
14 system we were using previously. This repository is accessible in
17 The full repository takes up about 80MB of disk space. A check out of
18 the blead branch (that is, the main development branch, which contains
19 bleadperl, the development version of perl 5) takes up about 160MB of
20 disk space (including the repository). A build of bleadperl takes up
21 about 200MB (including the repository and the check out).
23 =head1 GETTING ACCESS TO THE REPOSITORY
25 =head2 READ ACCESS VIA THE WEB
27 You may access the repository over the web. This allows you to browse
28 the tree, see recent commits, subscribe to RSS feeds for the changes,
29 search for particular commits and more. You may access it at:
31 http://perl5.git.perl.org/perl.git
33 A mirror of the repository is found at:
35 http://github.com/github/perl
37 =head2 READ ACCESS VIA GIT
39 You will need a copy of Git for your computer. You can fetch a copy of
40 the repository using the Git protocol (which uses port 9418):
42 git clone git://perl5.git.perl.org/perl.git perl-git
44 This clones the repository and makes a local copy in the F<perl-git>
47 If your local network does not allow you to use port 9418, then you can
48 fetch a copy of the repository over HTTP (this is at least 4x slower):
50 git clone http://perl5.git.perl.org/perl.git perl-http
52 This clones the repository and makes a local copy in the F<perl-http>
55 =head2 WRITE ACCESS TO THE REPOSITORY
57 If you are a committer, then you can fetch a copy of the repository
58 that you can push back on with:
60 git clone ssh://perl5.git.perl.org/perl.git perl-ssh
62 This clones the repository and makes a local copy in the F<perl-ssh>
65 If you cloned using the git protocol, which is faster than ssh, then
66 you will need to modify the URL for the origin remote to enable
67 pushing. To do that edit F<.git/config> with L<git-config(1)> like
70 git config remote.origin.url ssh://perl5.git.perl.org/perl.git
72 You can also set up your user name and e-mail address. For example
74 % git config user.name "Leon Brocard"
75 % git config user.email acme@astray.com
77 It is also possible to keep C<origin> as a git remote, and add a new
78 remote for ssh access:
80 % git remote add camel perl5.git.perl.org:/perl.git
82 This allows you to update your local repository by pulling from
83 C<origin>, which is faster and doesn't require you to authenticate, and
84 to push your changes back with the C<camel> remote:
89 The C<fetch> command just updates the C<camel> refs, as the objects
90 themselves should have been fetched when pulling from C<origin>.
92 =head2 A NOTE ON CAMEL AND DROMEDARY
94 The committers have SSH access to the two servers that serve
95 C<perl5.git.perl.org>. One is C<perl5.git.perl.org> itself (I<camel>),
96 which is the 'master' repository. The second one is
97 C<users.perl5.git.perl.org> (I<dromedary>), which can be used for
98 general testing and development. Dromedary syncs the git tree from
99 camel every few minutes, you should not push there. Both machines also
100 have a full CPAN mirror in /srv/CPAN, please use this. To share files
101 with the general public, dromedary serves your ~/public_html/ as
102 C<http://users.perl5.git.perl.org/~yourlogin/>
104 These hosts have fairly strict firewalls to the outside. Outgoing, only
105 rsync, ssh and git are allowed. For http and ftp, you can use
106 http://webproxy:3128 as proxy. Incoming, the firewall tries to detect
107 attacks and blocks IP addresses with suspicious activity. This
108 sometimes (but very rarely) has false positives and you might get
109 blocked. The quickest way to get unblocked is to notify the admins.
111 These two boxes are owned, hosted, and operated by booking.com. You can
112 reach the sysadmins in #p5p on irc.perl.org or via mail to
113 C<perl5-porters@perl.org>
115 =head1 OVERVIEW OF THE REPOSITORY
117 Once you have changed into the repository directory, you can inspect
120 After a clone the repository will contain a single local branch, which
121 will be the current branch as well, as indicated by the asterisk.
126 Using the -a switch to C<branch> will also show the remote tracking
127 branches in the repository:
135 The branches that begin with "origin" correspond to the "git remote"
136 that you cloned from (which is named "origin"). Each branch on the
137 remote will be exactly tracked by theses branches. You should NEVER do
138 work on these remote tracking branches. You only ever do work in a
139 local branch. Local branches can be configured to automerge (on pull)
140 from a designated remote tracking branch. This is the case with the
141 default branch C<blead> which will be configured to merge from the
142 remote tracking branch C<origin/blead>.
144 You can see recent commits:
148 And pull new changes from the repository, and update your local
149 repository (must be clean first)
153 Assuming we are on the branch C<blead> immediately after a pull, this
154 command would be more or less equivalent to:
157 % git merge origin/blead
159 In fact if you want to update your local repository without touching
160 your working directory you do:
164 And if you want to update your remote-tracking branches for all defined
165 remotes simultaneously you can do
169 Neither of these last two commands will update your working directory,
170 however both will update the remote-tracking branches in your
173 To switch to another branch:
175 % git checkout origin/maint-5.8-dor
177 To make a local branch of a remote branch:
179 % git checkout -b maint-5.10 origin/maint-5.10
181 To switch back to blead:
185 =head2 FINDING OUT YOUR STATUS
187 The most common git command you will use will probably be
191 This command will produce as output a description of the current state
192 of the repository, including modified files and unignored untracked
193 files, and in addition it will show things like what files have been
194 staged for the next commit, and usually some useful information about
195 how to change things. For instance the following:
199 # Your branch is ahead of 'origin/blead' by 1 commit.
201 # Changes to be committed:
202 # (use "git reset HEAD <file>..." to unstage)
204 # modified: pod/perlrepository.pod
206 # Changed but not updated:
207 # (use "git add <file>..." to update what will be committed)
209 # modified: pod/perlrepository.pod
212 # (use "git add <file>..." to include in what will be committed)
214 # deliberate.untracked
216 This shows that there were changes to this document staged for commit,
217 and that there were further changes in the working directory not yet
218 staged. It also shows that there was an untracked file in the working
219 directory, and as you can see shows how to change all of this. It also
220 shows that there is one commit on the working branch C<blead> which has
221 not been pushed to the C<origin> remote yet. B<NOTE>: that this output
222 is also what you see as a template if you do not provide a message to
225 Assuming that you'd like to commit all the changes you've just made as a
226 a single atomic unit, run this command:
230 (That C<-a> tells git to add every file you've changed to this commit.
231 New files aren't automatically added to your commit when you use C<commit
232 -a> If you want to add files or to commit some, but not all of your
233 changes, have a look at the documentation for C<git add>.)
235 Git will start up your favorite text editor, so that you can craft a
236 commit message for your change. See L</Commit message> below for more
237 information about what makes a good commit message.
239 Once you've finished writing your commit message and exited your editor,
240 git will write your change to disk and tell you something like this:
242 Created commit daf8e63: explain git status and stuff about remotes
243 1 files changed, 83 insertions(+), 3 deletions(-)
246 If you re-run C<git status>, you should see something like this:
250 # Your branch is ahead of 'origin/blead' by 2 commits.
253 # (use "git add <file>..." to include in what will be committed)
255 # deliberate.untracked
256 nothing added to commit but untracked files present (use "git add" to track)
259 When in doubt, before you do anything else, check your status and read
260 it carefully, many questions are answered directly by the git status
263 =head1 SUBMITTING A PATCH
265 If you have a patch in mind for Perl, you should first get a copy of
268 % git clone git://perl5.git.perl.org/perl.git perl-git
270 Then change into the directory:
274 Alternatively, if you already have a Perl repository, you should ensure
275 that you're on the I<blead> branch, and your repository is up to date:
280 It's preferable to patch against the latest blead version, since this
281 is where new development occurs for all changes other than critical bug
282 fixes. Critical bug fix patches should be made against the relevant
283 maint branches, or should be submitted with a note indicating all the
284 branches where the fix should be applied.
286 Now that we have everything up to date, we need to create a temporary
287 new branch for these changes and switch into it:
289 % git checkout -b orange
291 which is the short form of
294 % git checkout orange
296 Then make your changes. For example, if Leon Brocard changes his name
297 to Orange Brocard, we should change his name in the AUTHORS file:
299 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
301 You can see what files are changed:
305 # Changes to be committed:
306 # (use "git reset HEAD <file>..." to unstage)
311 And you can see the changes:
314 diff --git a/AUTHORS b/AUTHORS
315 index 293dd70..722c93e 100644
318 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
319 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
320 Leif Huhn <leif@hale.dkstat.com>
321 Len Johnson <lenjay@ibm.net>
322 -Leon Brocard <acme@astray.com>
323 +Orange Brocard <acme@astray.com>
324 Les Peters <lpeters@aol.net>
325 Lesley Binks <lesley.binks@gmail.com>
326 Lincoln D. Stein <lstein@cshl.org>
328 Now commit your change locally:
330 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
331 Created commit 6196c1d: Rename Leon Brocard to Orange Brocard
332 1 files changed, 1 insertions(+), 1 deletions(-)
334 You can examine your last commit with:
338 and if you are not happy with either the description or the patch
339 itself you can fix it up by editing the files once more and then issue:
341 % git commit -a --amend
343 Now you should create a patch file for all your local changes:
345 % git format-patch origin
346 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
348 You should now send an email to perl5-porters@perl.org with a
349 description of your changes, and include this patch file as an
350 attachment. (See the next section for how to configure and use git to
351 send these emails for you.)
353 If you want to delete your temporary branch, you may do so with:
356 % git branch -d orange
357 error: The branch 'orange' is not an ancestor of your current HEAD.
358 If you are sure you want to delete it, run 'git branch -D orange'.
359 % git branch -D orange
360 Deleted branch orange.
362 =head2 Using git to send patch emails
364 In your ~/git/perl repository, set the destination email to the
365 perl5-porters mailing list.
367 $ git config sendemail.to perl5-porters@perl.org
369 Then you can use git directly to send your patch emails:
371 $ git send-email 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
373 You may need to set some configuration variables for your particular
374 email service provider. For example, to set your global git config to
375 send email via a gmail account:
377 $ git config --global sendemail.smtpserver smtp.gmail.com
378 $ git config --global sendemail.smtpssl 1
379 $ git config --global sendemail.smtpuser YOURUSERNAME@gmail.com
381 With this configuration, you will be prompted for your gmail password
382 when you run 'git send-email'. You can also configure
383 C<sendemail.smtppass> with your password if you don't care about having
384 your password in the .gitconfig file.
386 =head2 A note on derived files
388 Be aware that many files in the distribution are derivative--avoid
389 patching them, because git won't see the changes to them, and the build
390 process will overwrite them. Patch the originals instead. Most
391 utilities (like perldoc) are in this category, i.e. patch
392 utils/perldoc.PL rather than utils/perldoc. Similarly, don't create
393 patches for files under $src_root/ext from their copies found in
394 $install_root/lib. If you are unsure about the proper location of a
395 file that may have gotten copied while building the source
396 distribution, consult the C<MANIFEST>.
398 As a special case, several files are regenerated by 'make regen' if
399 your patch alters C<embed.fnc>. These are needed for compilation, but
400 are included in the distribution so that you can build perl without
401 needing another perl to generate the files. You must test with these
402 regenerated files, but it is preferred that you instead note that
403 'make regen is needed' in both the email and the commit message, and
404 submit your patch without them. If you're submitting a series of
405 patches, it might be best to submit the regenerated changes
406 immediately after the source-changes that caused them, so as to have
407 as little effect as possible on the bisectability of your patchset.
411 What should we recommend about binary files now? Do we need anything?
413 =head2 Getting your patch accepted
415 If you are submitting a code patch there are several things that
422 As you craft each patch you intend to submit to the Perl core, it's
423 important to write a good commit message.
425 Your commit message should start with a description of the problem that
426 the patch corrects or new functionality that the patch adds.
428 As a general rule of thumb, your commit message should let a programmer
429 with a reasonable familiarity with the Perl core quickly understand what
430 you were trying to do, how you were trying to do it and why the change
437 Your commit message should describe what part of the Perl core you're
438 changing and what you expect your patch to do.
442 Perhaps most importantly, your commit message should describe why the
443 change you are making is important. When someone looks at your change
444 in six months or six years, your intent should be clear. If you're
445 deprecating a feature with the intent of later simplifying another bit
446 of code, say so. If you're fixing a performance problem or adding a new
447 feature to support some other bit of the core, mention that.
451 While it's not necessary for documentation changes, new tests or
452 trivial patches, it's often worth explaining how your change works.
453 Even if it's clear to you today, it may not be clear to a porter next
458 A commit message isn't intended to take the place of comments in your
459 code. Commit messages should describe the change you made, while code
460 comments should describe the current state of the code. If you've just
461 implemented a new feature, complete with doc, tests and well-commented
462 code, a brief commit message will often suffice. If, however, you've
463 just changed a single character deep in the parser or lexer, you might
464 need to write a small novel to ensure that future readers understand
465 what you did and why you did it.
467 =item Comments, Comments, Comments
469 Be sure to adequately comment your code. While commenting every line
470 is unnecessary, anything that takes advantage of side effects of
471 operators, that creates changes that will be felt outside of the
472 function being patched, or that others may find confusing should be
473 documented. If you are going to err, it is better to err on the side
474 of adding too many comments than too few.
478 In general, please follow the particular style of the code you are
481 In particular, follow these general guidelines for patching Perl
484 8-wide tabs (no exceptions!)
485 4-wide indents for code, 2-wide indents for nested CPP #defines
486 try hard not to exceed 79-columns
488 uncuddled elses and "K&R" style for indenting control constructs
489 no C++ style (//) comments
490 mark places that need to be revisited with XXX (and revisit often!)
491 opening brace lines up with "if" when conditional spans multiple
492 lines; should be at end-of-line otherwise
493 in function definitions, name starts in column 0 (return value is on
495 single space after keywords that are followed by parens, no space
496 between function name and following paren
497 avoid assignments in conditionals, but if they're unavoidable, use
498 extra paren, e.g. "if (a && (b = c)) ..."
499 "return foo;" rather than "return(foo);"
500 "if (!foo) ..." rather than "if (foo == FALSE) ..." etc.
504 If your patch changes code (rather than just changing documentation) you
505 should also include one or more test cases which illustrate the bug you're
506 fixing or validate the new functionality you're adding. In general,
507 you should update an existing test file rather than create a new one.
509 Your testsuite additions should generally follow these guidelines
510 (courtesy of Gurusamy Sarathy <gsar@activestate.com>):
512 Know what you're testing. Read the docs, and the source.
513 Tend to fail, not succeed.
514 Interpret results strictly.
515 Use unrelated features (this will flush out bizarre interactions).
516 Use non-standard idioms (otherwise you are not testing TIMTOWTDI).
517 Avoid using hardcoded test numbers whenever possible (the
518 EXPECTED/GOT found in t/op/tie.t is much more maintainable,
519 and gives better failure reports).
520 Give meaningful error messages when a test fails.
521 Avoid using qx// and system() unless you are testing for them. If you
522 do use them, make sure that you cover _all_ perl platforms.
523 Unlink any temporary files you create.
524 Promote unforeseen warnings to errors with $SIG{__WARN__}.
525 Be sure to use the libraries and modules shipped with the version
526 being tested, not those that were already installed.
527 Add comments to the code explaining what you are testing for.
528 Make updating the '1..42' string unnecessary. Or make sure that
530 Test _all_ behaviors of a given operator, library, or function:
531 - All optional arguments
532 - Return values in various contexts (boolean, scalar, list, lvalue)
533 - Use both global and lexical variables
534 - Don't forget the exceptional, pathological cases.
538 =head1 ACCEPTING A PATCH
540 If you have received a patch file generated using the above section,
541 you should try out the patch.
543 First we need to create a temporary new branch for these changes and
546 % git checkout -b experimental
548 Patches that were formatted by C<git format-patch> are applied with
551 % git am 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
552 Applying Rename Leon Brocard to Orange Brocard
554 If just a raw diff is provided, it is also possible use this two-step
557 % git apply bugfix.diff
558 % git commit -a -m "Some fixing" --author="That Guy <that.guy@internets.com>"
560 Now we can inspect the change:
563 commit b1b3dab48344cff6de4087efca3dbd63548ab5e2
564 Author: Leon Brocard <acme@astray.com>
565 Date: Fri Dec 19 17:02:59 2008 +0000
567 Rename Leon Brocard to Orange Brocard
569 diff --git a/AUTHORS b/AUTHORS
570 index 293dd70..722c93e 100644
573 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
574 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
575 Leif Huhn <leif@hale.dkstat.com>
576 Len Johnson <lenjay@ibm.net>
577 -Leon Brocard <acme@astray.com>
578 +Orange Brocard <acme@astray.com>
579 Les Peters <lpeters@aol.net>
580 Lesley Binks <lesley.binks@gmail.com>
581 Lincoln D. Stein <lstein@cshl.org>
583 If you are a committer to Perl and you think the patch is good, you can
584 then merge it into blead then push it out to the main repository:
587 % git merge experimental
590 If you want to delete your temporary branch, you may do so with:
593 % git branch -d experimental
594 error: The branch 'experimental' is not an ancestor of your current HEAD.
595 If you are sure you want to delete it, run 'git branch -D experimental'.
596 % git branch -D experimental
597 Deleted branch experimental.
599 =head1 CLEANING A WORKING DIRECTORY
601 The command C<git clean> can with varying arguments be used as a
602 replacement for C<make clean>.
604 To reset your working directory to a pristine condition you can do:
608 However, be aware this will delete ALL untracked content. You can use
612 to remove all ignored untracked files, such as build and test
613 byproduct, but leave any manually created files alone.
615 If you only want to cancel some uncommitted edits, you can use C<git
616 checkout> and give it a list of files to be reverted, or C<git checkout
617 -f> to revert them all.
619 If you want to cancel one or several commits, you can use C<git reset>.
623 C<git> provides a built-in way to determine, with a binary search in
624 the history, which commit should be blamed for introducing a given bug.
626 Suppose that we have a script F<~/testcase.pl> that exits with C<0>
627 when some behaviour is correct, and with C<1> when it's faulty. You need
628 an helper script that automates building C<perl> and running the
634 # If you can use ccache, add -Dcc=ccache\ gcc -Dld=gcc to the Configure line
635 # if Encode is not needed for the test, you can speed up the bisect by
636 # excluding it from the runs with -Dnoextensions=Encode
637 sh Configure -des -Dusedevel -Doptimize="-g"
638 test -f config.sh || exit 125
639 # Correct makefile for newer GNU gcc
640 perl -ni -we 'print unless /<(?:built-in|command)/' makefile x2p/makefile
641 # if you just need miniperl, replace test_prep with miniperl
643 [ -x ./perl ] || exit 125
644 ./perl -Ilib ~/testcase.pl
646 [ $ret -gt 127 ] && ret=127
650 This script may return C<125> to indicate that the corresponding commit
651 should be skipped. Otherwise, it returns the status of
654 You first enter in bisect mode with:
658 For example, if the bug is present on C<HEAD> but wasn't in 5.10.0,
659 C<git> will learn about this when you enter:
662 % git bisect good perl-5.10.0
663 Bisecting: 853 revisions left to test after this
665 This results in checking out the median commit between C<HEAD> and
666 C<perl-5.10.0>. You can then run the bisecting process with:
668 % git bisect run ~/run
670 When the first bad commit is isolated, C<git bisect> will tell you so:
672 ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 is first bad commit
673 commit ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5
674 Author: Dave Mitchell <davem@fdisolutions.com>
675 Date: Sat Feb 9 14:56:23 2008 +0000
677 [perl #49472] Attributes + Unknown Error
682 You can peek into the bisecting process with C<git bisect log> and
683 C<git bisect visualize>. C<git bisect reset> will get you out of bisect
686 Please note that the first C<good> state must be an ancestor of the
687 first C<bad> state. If you want to search for the commit that I<solved>
688 some bug, you have to negate your test case (i.e. exit with C<1> if OK
689 and C<0> if not) and still mark the lower bound as C<good> and the
690 upper as C<bad>. The "first bad commit" has then to be understood as
691 the "first commit where the bug is solved".
693 C<git help bisect> has much more information on how you can tweak your
696 =head1 SUBMITTING A PATCH VIA GITHUB
698 GitHub is a website that makes it easy to fork and publish projects
699 with Git. First you should set up a GitHub account and log in.
701 Perl's git repository is mirrored on GitHub at this page:
703 http://github.com/github/perl/tree/blead
705 Visit the page and click the "fork" button. This clones the Perl git
706 repository for you and provides you with "Your Clone URL" from which
709 % git clone git@github.com:USERNAME/perl.git perl-github
711 The same patch as above, using github might look like this:
714 % git remote add upstream git://github.com/github/perl.git
715 % git pull upstream blead
716 % git checkout -b orange
717 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
718 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
719 % git push origin orange
721 The orange branch has been pushed to GitHub, so you should now send an
722 email to perl5-porters@perl.org with a description of your changes and
723 the following information:
725 http://github.com/USERNAME/perl/tree/orange
726 git@github.com:USERNAME/perl.git branch orange
728 =head1 MERGING FROM A BRANCH VIA GITHUB
730 If someone has provided a branch via GitHub and you are a committer,
731 you should use the following in your perl-ssh directory:
733 % git remote add dandv git://github.com/dandv/perl.git
736 Now you can see the differences between the branch and blead:
738 % git diff dandv/blead
740 And you can see the commits:
742 % git log dandv/blead
744 If you approve of a specific commit, you can cherry pick it:
746 % git cherry-pick 3adac458cb1c1d41af47fc66e67b49c8dec2323f
748 Or you could just merge the whole branch if you like it all:
750 % git merge dandv/blead
752 And then push back to the repository:
757 =head1 TOPIC BRANCHES AND REWRITING HISTORY
759 Individual committers should create topic branches under
760 B<yourname>/B<some_descriptive_name>. Other committers should check
761 with a topic branch's creator before making any change to it.
763 If you are not the creator of B<yourname>/B<some_descriptive_name>, you
764 might sometimes find that the original author has edited the branch's
765 history. There are lots of good reasons for this. Sometimes, an author
766 might simply be rebasing the branch onto a newer source point.
767 Sometimes, an author might have found an error in an early commit which
768 they wanted to fix before merging the branch to blead.
770 Currently the master repository is configured to forbid
771 non-fast-forward merges. This means that the branches within can not
772 be rebased and pushed as a single step.
774 The only way you will ever be allowed to rebase or modify the history
775 of a pushed branch is to delete it and push it as a new branch under
776 the same name. Please think carefully about doing this. It may be
777 better to sequentially rename your branches so that it is easier for
778 others working with you to cherry-pick their local changes onto the new
779 version. (XXX: needs explanation).
781 If you want to rebase a personal topic branch, you will have to delete
782 your existing topic branch and push as a new version of it. You can do
783 this via the following formula (see the explanation about C<refspec>'s
784 in the git push documentation for details) after you have rebased your
788 $ git checkout $user/$topic
790 $ git rebase origin/blead
792 # then "delete-and-push"
793 $ git push origin :$user/$topic
794 $ git push origin $user/$topic
796 B<NOTE:> it is forbidden at the repository level to delete any of the
797 "primary" branches. That is any branch matching
798 C<m!^(blead|maint|perl)!>. Any attempt to do so will result in git
799 producing an error like this:
801 $ git push origin :blead
802 *** It is forbidden to delete blead/maint branches in this repository
803 error: hooks/update exited with error code 1
804 error: hook declined to update refs/heads/blead
805 To ssh://perl5.git.perl.org/perl
806 ! [remote rejected] blead (hook declined)
807 error: failed to push some refs to 'ssh://perl5.git.perl.org/perl'
809 As a matter of policy we do B<not> edit the history of the blead and
810 maint-* branches. If a typo (or worse) sneaks into a commit to blead or
811 maint-*, we'll fix it in another commit. The only types of updates
812 allowed on these branches are "fast-forward's", where all history is
815 Annotated tags in the canonical perl.git repository will never be
816 deleted or modified. Think long and hard about whether you want to push
817 a local tag to perl.git before doing so. (Pushing unannotated tags is
820 =head1 COMMITTING TO MAINTENANCE VERSIONS
822 Maintenance versions should only be altered to add critical bug fixes.
824 To commit to a maintenance version of perl, you need to create a local
827 % git checkout --track -b maint-5.005 origin/maint-5.005
829 This creates a local branch named C<maint-5.005>, which tracks the
830 remote branch C<origin/maint-5.005>. Then you can pull, commit, merge
833 You can also cherry-pick commits from blead and another branch, by
834 using the C<git cherry-pick> command. It is recommended to use the
835 B<-x> option to C<git cherry-pick> in order to record the SHA1 of the
836 original commit in the new commit message.
840 The perl history contains one mistake which was not caught in the
841 conversion: a merge was recorded in the history between blead and
842 maint-5.10 where no merge actually occurred. Due to the nature of git,
843 this is now impossible to fix in the public repository. You can remove
844 this mis-merge locally by adding the following line to your
845 C<.git/info/grafts> file:
847 296f12bbbbaa06de9be9d09d3dcf8f4528898a49 434946e0cb7a32589ed92d18008aaa1d88515930
849 It is particularly important to have this graft line if any bisecting
850 is done in the area of the "merge" in question.
856 The git documentation, accessible via C<git help command>.