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 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 your config in order to enable pushing. Edit
67 F<.git/config> where you will see something like:
70 url = git://perl5.git.perl.org/perl.git
72 change that to something like this:
75 url = ssh://perl5.git.perl.org/perl.git
77 You can also set up your user name and e-mail address. For example
79 % git config user.name "Leon Brocard"
80 % git config user.email acme@astray.com
82 It is also possible to keep C<origin> as a git remote, and add a new
83 remote for ssh access:
85 % git remote add camel perl5.git.perl.org:/perl.git
87 This allows you to update your local repository by pulling from
88 C<origin>, which is faster and doesn't require you to authenticate, and
89 to push your changes back with the C<camel> remote:
94 The C<fetch> command just updates the C<camel> refs, as the objects
95 themselves should have been fetched when pulling from C<origin>.
97 =head2 A NOTE ON CAMEL AND DROMEDARY
99 The committers have SSH access to the two servers that serve
100 C<perl5.git.perl.org>. One is C<perl5.git.perl.org> itself (I<camel>),
101 which is the 'master' repository. The second one is
102 C<users.perl5.git.perl.org> (I<dromedary>), which can be used for
103 general testing and development. Dromedary syncs the git tree from
104 camel every few minutes, you should not push there. Both machines also
105 have a full CPAN mirror in /srv/CPAN, please use this. To share files
106 with the general public, dromedary serves your ~/public_html/ as
107 C<http://users.perl5.git.perl.org/~yourlogin/>
109 These hosts have fairly strict firewalls to the outside. Outgoing, only
110 rsync, ssh and git are allowed. For http and ftp, you can use
111 http://webproxy:3128 as proxy. Incoming, the firewall tries to detect
112 attacks and blocks IP addresses with suspicious activity. This
113 sometimes (but very rarely) has false positives and you might get
114 blocked. The quickest way to get unblocked is to notify the admins.
116 These two boxes are owned, hosted, and operated by booking.com. You can
117 reach the sysadmins in #p5p on irc.perl.org or via mail to
118 C<perl5-porters@perl.org>
120 =head1 OVERVIEW OF THE REPOSITORY
122 Once you have changed into the repository directory, you can inspect
125 After a clone the repository will contain a single local branch, which
126 will be the current branch as well, as indicated by the asterisk.
131 Using the -a switch to C<branch> will also show the remote tracking
132 branches in the repository:
140 The branches that begin with "origin" correspond to the "git remote"
141 that you cloned from (which is named "origin"). Each branch on the
142 remote will be exactly tracked by theses branches. You should NEVER do
143 work on these remote tracking branches. You only ever do work in a
144 local branch. Local branches can be configured to automerge (on pull)
145 from a designated remote tracking branch. This is the case with the
146 default branch C<blead> which will be configured to merge from the
147 remote tracking branch C<origin/blead>.
149 You can see recent commits:
153 And pull new changes from the repository, and update your local
154 repository (must be clean first)
158 Assuming we are on the branch C<blead> immediately after a pull, this
159 command would be more or less equivalent to:
162 % git merge origin/blead
164 In fact if you want to update your local repository without touching
165 your working directory you do:
169 And if you want to update your remote-tracking branches for all defined
170 remotes simultaneously you can do
174 Neither of these last two commands will update your working directory,
175 however both will update the remote-tracking branches in your
178 To switch to another branch:
180 % git checkout origin/maint-5.8-dor
182 To make a local branch of a remote branch:
184 % git checkout -b maint-5.10 origin/maint-5.10
186 To switch back to blead:
190 =head2 FINDING OUT YOUR STATUS
192 The most common git command you will use will probably be
196 This command will produce as output a description of the current state
197 of the repository, including modified files and unignored untracked
198 files, and in addition it will show things like what files have been
199 staged for the next commit, and usually some useful information about
200 how to change things. For instance the following:
204 # Your branch is ahead of 'origin/blead' by 1 commit.
206 # Changes to be committed:
207 # (use "git reset HEAD <file>..." to unstage)
209 # modified: pod/perlrepository.pod
211 # Changed but not updated:
212 # (use "git add <file>..." to update what will be committed)
214 # modified: pod/perlrepository.pod
217 # (use "git add <file>..." to include in what will be committed)
219 # deliberate.untracked
221 This shows that there were changes to this document staged for commit,
222 and that there were further changes in the working directory not yet
223 staged. It also shows that there was an untracked file in the working
224 directory, and as you can see shows how to change all of this. It also
225 shows that there is one commit on the working branch C<blead> which has
226 not been pushed to the C<origin> remote yet. B<NOTE>: that this output
227 is also what you see as a template if you do not provide a message to
230 Assuming that you'd like to commit all the changes you've just made as a
231 a single atomic unit, run this command:
235 (That C<-a> tells git to add every file you've changed to this commit.
236 If you want to commit some, but not all of your changes, have a look
237 at the documentation for C<git add>.)
239 Git will start up your favorite text editor, so that you can craft a
240 commit message for your change. See L</Commit message> below for more
241 information about what makes a good commit message.
243 Once you've finished writing your commit message and exited your editor,
244 git will write your change to disk and tell you something like this:
246 Created commit daf8e63: explain git status and stuff about remotes
247 1 files changed, 83 insertions(+), 3 deletions(-)
250 If you re-run C<git status>, you should see something like this:
254 # Your branch is ahead of 'origin/blead' by 2 commits.
257 # (use "git add <file>..." to include in what will be committed)
259 # deliberate.untracked
260 nothing added to commit but untracked files present (use "git add" to track)
263 When in doubt, before you do anything else, check your status and read
264 it carefully, many questions are answered directly by the git status
267 =head1 SUBMITTING A PATCH
269 If you have a patch in mind for Perl, you should first get a copy of
272 % git clone git://perl5.git.perl.org/perl.git perl-git
274 Then change into the directory:
278 Alternatively, if you already have a Perl repository, you should ensure
279 that you're on the I<blead> branch, and your repository is up to date:
284 It's preferable to patch against the latest blead version, since this
285 is where new development occurs for all changes other than critical bug
286 fixes. Critical bug fix patches should be made against the relevant
287 maint branches, or should be submitted with a note indicating all the
288 branches where the fix should be applied.
290 Now that we have everything up to date, we need to create a temporary
291 new branch for these changes and switch into it:
293 % git checkout -b orange
295 which is the short form of
298 % git checkout orange
300 Then make your changes. For example, if Leon Brocard changes his name
301 to Orange Brocard, we should change his name in the AUTHORS file:
303 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
305 You can see what files are changed:
309 # Changes to be committed:
310 # (use "git reset HEAD <file>..." to unstage)
315 And you can see the changes:
318 diff --git a/AUTHORS b/AUTHORS
319 index 293dd70..722c93e 100644
322 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
323 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
324 Leif Huhn <leif@hale.dkstat.com>
325 Len Johnson <lenjay@ibm.net>
326 -Leon Brocard <acme@astray.com>
327 +Orange Brocard <acme@astray.com>
328 Les Peters <lpeters@aol.net>
329 Lesley Binks <lesley.binks@gmail.com>
330 Lincoln D. Stein <lstein@cshl.org>
332 Now commit your change locally:
334 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
335 Created commit 6196c1d: Rename Leon Brocard to Orange Brocard
336 1 files changed, 1 insertions(+), 1 deletions(-)
338 You can examine your last commit with:
342 and if you are not happy with either the description or the patch
343 itself you can fix it up by editing the files once more and then issue:
345 % git commit -a --amend
347 Now you should create a patch file for all your local changes:
349 % git format-patch origin
350 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
352 You should now send an email to perl5-porters@perl.org with a
353 description of your changes, and include this patch file as an
354 attachment. (See the next section for how to configure and use git to
355 send these emails for you.)
357 If you want to delete your temporary branch, you may do so with:
360 % git branch -d orange
361 error: The branch 'orange' is not an ancestor of your current HEAD.
362 If you are sure you want to delete it, run 'git branch -D orange'.
363 % git branch -D orange
364 Deleted branch orange.
366 =head2 Using git to send patch emails
368 In your ~/git/perl repository, set the destination email to the
369 perl5-porters mailing list.
371 $ git config sendemail.to perl5-porters@perl.org
373 Then you can use git directly to send your patch emails:
375 $ git send-email 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
377 You may need to set some configuration variables for your particular
378 email service provider. For example, to set your global git config to
379 send email via a gmail account:
381 $ git config --global sendemail.smtpserver smtp.gmail.com
382 $ git config --global sendemail.smtpssl 1
383 $ git config --global sendemail.smtpuser YOURUSERNAME@gmail.com
385 With this configuration, you will be prompted for your gmail password
386 when you run 'git send-email'. You can also configure
387 C<sendemail.smtppass> with your password if you don't care about having
388 your password in the .gitconfig file.
390 =head2 A note on derived files
392 Be aware that many files in the distribution are derivative--avoid
393 patching them, because git won't see the changes to them, and the build
394 process will overwrite them. Patch the originals instead. Most
395 utilities (like perldoc) are in this category, i.e. patch
396 utils/perldoc.PL rather than utils/perldoc. Similarly, don't create
397 patches for files under $src_root/ext from their copies found in
398 $install_root/lib. If you are unsure about the proper location of a
399 file that may have gotten copied while building the source
400 distribution, consult the C<MANIFEST>.
404 What should we recommend about binary files now? Do we need anything?
406 =head2 Getting your patch accepted
408 If you are submitting a code patch there are several things that
415 As you craft each patch you intend to submit to the Perl core, it's
416 important to write a good commit message.
418 Your commit message should start with a description of the problem that
419 the patch corrects or new functionality that the patch adds.
422 As a general rule of thumb, your commit message should let a programmer
423 with a reasonable familiarity with the Perl core quickly understand what
424 you were trying to do, how you were trying to do it and why the change
431 Your commit message should describe what part of the Perl core you're changing and what you expect your patch to do.
435 Perhaps most importantly, your commit message should describe why the
436 change you are making is important. When someone looks at your change
437 in six months or six years, your intent should be clear. If you're
438 deprecating a feature with the intent of later simplifying another bit
439 of code, say so. If you're fixing a performance problem or adding a new
440 feature to support some other bit of the core, mention that.
444 While it's not necessary for documentation changes, new tests or
445 trivial patches, it's often worth explaining how your change works.
446 Even if it's clear to you today, it may not be clear to a porter next
453 =item Comments, Comments, Comments
455 Be sure to adequately comment your code. While commenting every line
456 is unnecessary, anything that takes advantage of side effects of
457 operators, that creates changes that will be felt outside of the
458 function being patched, or that others may find confusing should be
459 documented. If you are going to err, it is better to err on the side
460 of adding too many comments than too few.
464 In general, please follow the particular style of the code you are
467 In particular, follow these general guidelines for patching Perl
470 8-wide tabs (no exceptions!)
471 4-wide indents for code, 2-wide indents for nested CPP #defines
472 try hard not to exceed 79-columns
474 uncuddled elses and "K&R" style for indenting control constructs
475 no C++ style (//) comments
476 mark places that need to be revisited with XXX (and revisit often!)
477 opening brace lines up with "if" when conditional spans multiple
478 lines; should be at end-of-line otherwise
479 in function definitions, name starts in column 0 (return value is on
481 single space after keywords that are followed by parens, no space
482 between function name and following paren
483 avoid assignments in conditionals, but if they're unavoidable, use
484 extra paren, e.g. "if (a && (b = c)) ..."
485 "return foo;" rather than "return(foo);"
486 "if (!foo) ..." rather than "if (foo == FALSE) ..." etc.
490 If your patch changes code (rather than just changing documentation) you
491 should also include one or more test cases which illustrate the bug you're
492 fixing or validate the new functionality you're adding. In general,
493 you should update an existing test file rather than create a new one.
495 Your testsuite additions should generally follow these guidelines
496 (courtesy of Gurusamy Sarathy <gsar@activestate.com>):
498 Know what you're testing. Read the docs, and the source.
499 Tend to fail, not succeed.
500 Interpret results strictly.
501 Use unrelated features (this will flush out bizarre interactions).
502 Use non-standard idioms (otherwise you are not testing TIMTOWTDI).
503 Avoid using hardcoded test numbers whenever possible (the
504 EXPECTED/GOT found in t/op/tie.t is much more maintainable,
505 and gives better failure reports).
506 Give meaningful error messages when a test fails.
507 Avoid using qx// and system() unless you are testing for them. If you
508 do use them, make sure that you cover _all_ perl platforms.
509 Unlink any temporary files you create.
510 Promote unforeseen warnings to errors with $SIG{__WARN__}.
511 Be sure to use the libraries and modules shipped with the version
512 being tested, not those that were already installed.
513 Add comments to the code explaining what you are testing for.
514 Make updating the '1..42' string unnecessary. Or make sure that
516 Test _all_ behaviors of a given operator, library, or function:
517 - All optional arguments
518 - Return values in various contexts (boolean, scalar, list, lvalue)
519 - Use both global and lexical variables
520 - Don't forget the exceptional, pathological cases.
524 =head1 ACCEPTING A PATCH
526 If you have received a patch file generated using the above section,
527 you should try out the patch.
529 First we need to create a temporary new branch for these changes and
532 % git checkout -b experimental
534 Patches that were formatted by C<git format-patch> are applied with
537 % git am 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
538 Applying Rename Leon Brocard to Orange Brocard
540 If just a raw diff is provided, it is also possible use this two-step
543 % git apply bugfix.diff
544 % git commit -a -m "Some fixing" --author="That Guy <that.guy@internets.com>"
546 Now we can inspect the change:
549 commit b1b3dab48344cff6de4087efca3dbd63548ab5e2
550 Author: Leon Brocard <acme@astray.com>
551 Date: Fri Dec 19 17:02:59 2008 +0000
553 Rename Leon Brocard to Orange Brocard
555 diff --git a/AUTHORS b/AUTHORS
556 index 293dd70..722c93e 100644
559 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
560 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
561 Leif Huhn <leif@hale.dkstat.com>
562 Len Johnson <lenjay@ibm.net>
563 -Leon Brocard <acme@astray.com>
564 +Orange Brocard <acme@astray.com>
565 Les Peters <lpeters@aol.net>
566 Lesley Binks <lesley.binks@gmail.com>
567 Lincoln D. Stein <lstein@cshl.org>
569 If you are a committer to Perl and you think the patch is good, you can
570 then merge it into blead then push it out to the main repository:
573 % git merge experimental
576 If you want to delete your temporary branch, you may do so with:
579 % git branch -d experimental
580 error: The branch 'experimental' is not an ancestor of your current HEAD.
581 If you are sure you want to delete it, run 'git branch -D experimental'.
582 % git branch -D experimental
583 Deleted branch experimental.
585 =head1 CLEANING A WORKING DIRECTORY
587 The command C<git clean> can with varying arguments be used as a
588 replacement for C<make clean>.
590 To reset your working directory to a pristine condition you can do:
594 However, be aware this will delete ALL untracked content. You can use
598 to remove all ignored untracked files, such as build and test
599 byproduct, but leave any manually created files alone.
601 If you only want to cancel some uncommitted edits, you can use C<git
602 checkout> and give it a list of files to be reverted, or C<git checkout
603 -f> to revert them all.
605 If you want to cancel one or several commits, you can use C<git reset>.
609 C<git> provides a built-in way to determine, with a binary search in
610 the history, which commit should be blamed for introducing a given bug.
612 Suppose that we have a script F<~/testcase.pl> that exits with C<0>
613 when some behaviour is correct, and with C<1> when it's faulty. You need
614 an helper script that automates building C<perl> and running the
620 # If you can use ccache, add -Dcc=ccache\ gcc -Dld=gcc to the Configure line
621 # if Encode is not needed for the test, you can speed up the bisect by
622 # excluding it from the runs with -Dnoextensions=Encode
623 sh Configure -des -Dusedevel -Doptimize="-g"
624 test -f config.sh || exit 125
625 # Correct makefile for newer GNU gcc
626 perl -ni -we 'print unless /<(?:built-in|command)/' makefile x2p/makefile
627 # if you just need miniperl, replace test_prep with miniperl
629 [ -x ./perl ] || exit 125
630 ./perl -Ilib ~/testcase.pl
632 [ $ret -gt 127 ] && ret=127
636 This script may return C<125> to indicate that the corresponding commit
637 should be skipped. Otherwise, it returns the status of
640 You first enter in bisect mode with:
644 For example, if the bug is present on C<HEAD> but wasn't in 5.10.0,
645 C<git> will learn about this when you enter:
648 % git bisect good perl-5.10.0
649 Bisecting: 853 revisions left to test after this
651 This results in checking out the median commit between C<HEAD> and
652 C<perl-5.10.0>. You can then run the bisecting process with:
654 % git bisect run ~/run
656 When the first bad commit is isolated, C<git bisect> will tell you so:
658 ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 is first bad commit
659 commit ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5
660 Author: Dave Mitchell <davem@fdisolutions.com>
661 Date: Sat Feb 9 14:56:23 2008 +0000
663 [perl #49472] Attributes + Unknown Error
668 You can peek into the bisecting process with C<git bisect log> and
669 C<git bisect visualize>. C<git bisect reset> will get you out of bisect
672 Please note that the first C<good> state must be an ancestor of the
673 first C<bad> state. If you want to search for the commit that I<solved>
674 some bug, you have to negate your test case (i.e. exit with C<1> if OK
675 and C<0> if not) and still mark the lower bound as C<good> and the
676 upper as C<bad>. The "first bad commit" has then to be understood as
677 the "first commit where the bug is solved".
679 C<git help bisect> has much more information on how you can tweak your
682 =head1 SUBMITTING A PATCH VIA GITHUB
684 GitHub is a website that makes it easy to fork and publish projects
685 with Git. First you should set up a GitHub account and log in.
687 Perl's git repository is mirrored on GitHub at this page:
689 http://github.com/github/perl/tree/blead
691 Visit the page and click the "fork" button. This clones the Perl git
692 repository for you and provides you with "Your Clone URL" from which
695 % git clone git@github.com:USERNAME/perl.git perl-github
697 The same patch as above, using github might look like this:
700 % git remote add upstream git://github.com/github/perl.git
701 % git pull upstream blead
702 % git checkout -b orange
703 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
704 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
705 % git push origin orange
707 The orange branch has been pushed to GitHub, so you should now send an
708 email to perl5-porters@perl.org with a description of your changes and
709 the following information:
711 http://github.com/USERNAME/perl/tree/orange
712 git@github.com:USERNAME/perl.git branch orange
714 =head1 MERGING FROM A BRANCH VIA GITHUB
716 If someone has provided a branch via GitHub and you are a committer,
717 you should use the following in your perl-ssh directory:
719 % git remote add dandv git://github.com/dandv/perl.git
722 Now you can see the differences between the branch and blead:
724 % git diff dandv/blead
726 And you can see the commits:
728 % git log dandv/blead
730 If you approve of a specific commit, you can cherry pick it:
732 % git cherry-pick 3adac458cb1c1d41af47fc66e67b49c8dec2323f
734 Or you could just merge the whole branch if you like it all:
736 % git merge dandv/blead
738 And then push back to the repository:
743 =head1 TOPIC BRANCHES AND REWRITING HISTORY
745 Individual committers should create topic branches under
746 B<yourname>/B<some_descriptive_name>. Other committers should check
747 with a topic branch's creator before making any change to it.
749 If you are not the creator of B<yourname>/B<some_descriptive_name>, you
750 might sometimes find that the original author has edited the branch's
751 history. There are lots of good reasons for this. Sometimes, an author
752 might simply be rebasing the branch onto a newer source point.
753 Sometimes, an author might have found an error in an early commit which
754 they wanted to fix before merging the branch to blead.
756 Currently the master repository is configured to forbid
757 non-fast-forward merges. This means that the branches within can not
758 be rebased and pushed as a single step.
760 The only way you will ever be allowed to rebase or modify the history
761 of a pushed branch is to delete it and push it as a new branch under
762 the same name. Please think carefully about doing this. It may be
763 better to sequentially rename your branches so that it is easier for
764 others working with you to cherry-pick their local changes onto the new
765 version. (XXX: needs explanation).
767 If you want to rebase a personal topic branch, you will have to delete
768 your existing topic branch and push as a new version of it. You can do
769 this via the following formula (see the explanation about C<refspec>'s
770 in the git push documentation for details) after you have rebased your
774 $ git checkout $user/$topic
776 $ git rebase origin/blead
778 # then "delete-and-push"
779 $ git push origin :$user/$topic
780 $ git push origin $user/$topic
782 B<NOTE:> it is forbidden at the repository level to delete any of the
783 "primary" branches. That is any branch matching
784 C<m!^(blead|maint|perl)!>. Any attempt to do so will result in git
785 producing an error like this:
787 $ git push origin :blead
788 *** It is forbidden to delete blead/maint branches in this repository
789 error: hooks/update exited with error code 1
790 error: hook declined to update refs/heads/blead
791 To ssh://perl5.git.perl.org/perl
792 ! [remote rejected] blead (hook declined)
793 error: failed to push some refs to 'ssh://perl5.git.perl.org/perl'
795 As a matter of policy we do B<not> edit the history of the blead and
796 maint-* branches. If a typo (or worse) sneaks into a commit to blead or
797 maint-*, we'll fix it in another commit. The only types of updates
798 allowed on these branches are "fast-forward's", where all history is
801 Annotated tags in the canonical perl.git repository will never be
802 deleted or modified. Think long and hard about whether you want to push
803 a local tag to perl.git before doing so. (Pushing unannotated tags is
806 =head1 COMMITTING TO MAINTENANCE VERSIONS
808 Maintenance versions should only be altered to add critical bug fixes.
810 To commit to a maintenance version of perl, you need to create a local
813 % git checkout --track -b maint-5.005 origin/maint-5.005
815 This creates a local branch named C<maint-5.005>, which tracks the
816 remote branch C<origin/maint-5.005>. Then you can pull, commit, merge
819 You can also cherry-pick commits from blead and another branch, by
820 using the C<git cherry-pick> command. It is recommended to use the
821 B<-x> option to C<git cherry-pick> in order to record the SHA1 of the
822 original commit in the new commit message.
826 The perl history contains one mistake which was not caught in the
827 conversion -- a merge was recorded in the history between blead and
828 maint-5.10 where no merge actually occurred. Due to the nature of git,
829 this is now impossible to fix in the public repository. You can remove
830 this mis-merge locally by adding the following line to your
831 C<.git/info/grafts> file:
833 296f12bbbbaa06de9be9d09d3dcf8f4528898a49 434946e0cb7a32589ed92d18008aaa1d88515930
835 It is particularly important to have this graft line if any bisecting
836 is done in the area of the "merge" in question.
842 The git documentation, accessible via C<git help command>.