FM / pod

/usr/share/perl5/pod

Name	Size	Mode	Actions
a2p.pod	6107	0644	edit dl rm
perl.pod	15748	0644	edit dl rm
perl56delta.pod	107184	0644	edit dl rm
perl58delta.pod	114908	0644	edit dl rm
perl561delta.pod	124697	0644	edit dl rm
perl570delta.pod	21655	0644	edit dl rm
perl571delta.pod	30382	0644	edit dl rm
perl572delta.pod	25551	0644	edit dl rm
perl573delta.pod	4644	0644	edit dl rm
perl581delta.pod	38060	0644	edit dl rm
perl582delta.pod	4470	0644	edit dl rm
perl583delta.pod	6335	0644	edit dl rm
perl584delta.pod	7363	0644	edit dl rm
perl585delta.pod	5889	0644	edit dl rm
perl586delta.pod	4651	0644	edit dl rm
perl587delta.pod	8357	0644	edit dl rm
perl588delta.pod	25267	0644	edit dl rm
perl589delta.pod	53905	0644	edit dl rm
perl590delta.pod	34951	0644	edit dl rm
perl591delta.pod	11173	0644	edit dl rm
perl592delta.pod	10954	0644	edit dl rm
perl593delta.pod	17034	0644	edit dl rm
perl594delta.pod	12661	0644	edit dl rm
perl595delta.pod	18934	0644	edit dl rm
perl5004delta.pod	56240	0644	edit dl rm
perl5005delta.pod	34285	0644	edit dl rm
perl5100delta.pod	53922	0644	edit dl rm
perl5101delta.pod	43877	0644	edit dl rm
perlaix.pod	18128	0644	edit dl rm
perlamiga.pod	7031	0644	edit dl rm
perlapi.pod	169428	0644	edit dl rm
perlapio.pod	19332	0644	edit dl rm
perlapollo.pod	829	0644	edit dl rm
perlartistic.pod	6802	0644	edit dl rm
perlbeos.pod	2939	0644	edit dl rm
perlbook.pod	663	0644	edit dl rm
perlboot.pod	28355	0644	edit dl rm
perlbot.pod	11675	0644	edit dl rm
perlbs2000.pod	7929	0644	edit dl rm
perlcall.pod	55173	0644	edit dl rm
perlce.pod	9257	0644	edit dl rm
perlcheat.pod	4153	0644	edit dl rm
perlclib.pod	7684	0644	edit dl rm
perlcn.pod	4915	0644	edit dl rm
perlcommunity.pod	6398	0644	edit dl rm
perlcompile.pod	9516	0644	edit dl rm
perlcygwin.pod	28183	0644	edit dl rm
perldata.pod	36879	0644	edit dl rm
perldbmfilter.pod	4987	0644	edit dl rm
perldebguts.pod	31887	0644	edit dl rm
perldebtut.pod	21304	0644	edit dl rm
perldebug.pod	37535	0644	edit dl rm
perldelta.pod	43877	0644	edit dl rm
perldgux.pod	2821	0644	edit dl rm
perldiag.pod	183151	0644	edit dl rm
perldoc.pod	7310	0644	edit dl rm
perldos.pod	10853	0644	edit dl rm
perldsc.pod	25447	0644	edit dl rm
perlebcdic.pod	66607	0644	edit dl rm
perlembed.pod	38033	0644	edit dl rm
perlepoc.pod	3779	0644	edit dl rm
perlfaq.pod	24841	0644	edit dl rm
perlfaq1.pod	17762	0644	edit dl rm
perlfaq2.pod	21614	0644	edit dl rm
perlfaq3.pod	38534	0644	edit dl rm
perlfaq4.pod	81412	0644	edit dl rm
perlfaq5.pod	49201	0644	edit dl rm
perlfaq6.pod	38538	0644	edit dl rm
perlfaq7.pod	37588	0644	edit dl rm
perlfaq8.pod	46128	0644	edit dl rm
perlfaq9.pod	24191	0644	edit dl rm
perlfilter.pod	21140	0644	edit dl rm
perlfork.pod	11440	0644	edit dl rm
perlform.pod	16894	0644	edit dl rm
perlfreebsd.pod	1950	0644	edit dl rm
perlfunc.pod	291909	0644	edit dl rm
perlglossary.pod	112139	0644	edit dl rm
perlgpl.pod	18806	0644	edit dl rm
perlguts.pod	105182	0644	edit dl rm
perlhack.pod	121512	0644	edit dl rm
perlhaiku.pod	1504	0644	edit dl rm
perlhist.pod	38766	0644	edit dl rm
perlhpux.pod	28650	0644	edit dl rm
perlhurd.pod	1990	0644	edit dl rm
perlintern.pod	26408	0644	edit dl rm
perlintro.pod	21491	0644	edit dl rm
perliol.pod	33755	0644	edit dl rm
perlipc.pod	67761	0644	edit dl rm
perlirix.pod	4397	0644	edit dl rm
perljp.pod	8070	0644	edit dl rm
perlko.pod	7892	0644	edit dl rm
perllexwarn.pod	14435	0644	edit dl rm
perllinux.pod	1492	0644	edit dl rm
perllocale.pod	41616	0644	edit dl rm
perllol.pod	8252	0644	edit dl rm
perlmachten.pod	4500	0644	edit dl rm
perlmacos.pod	2111	0644	edit dl rm
perlmacosx.pod	11322	0644	edit dl rm
perlmint.pod	9539	0644	edit dl rm
perlmod.pod	24494	0644	edit dl rm
perlmodinstall.pod	13929	0644	edit dl rm
perlmodlib.pod	77333	0644	edit dl rm
perlmodstyle.pod	21114	0644	edit dl rm
perlmpeix.pod	15087	0644	edit dl rm
perlmroapi.pod	2959	0644	edit dl rm
perlnetware.pod	6488	0644	edit dl rm
perlnewmod.pod	11214	0644	edit dl rm
perlnumber.pod	8352	0644	edit dl rm
perlobj.pod	21813	0644	edit dl rm
perlop.pod	96225	0644	edit dl rm
perlopenbsd.pod	1207	0644	edit dl rm
perlopentut.pod	37997	0644	edit dl rm
perlos2.pod	92783	0644	edit dl rm
perlos390.pod	16074	0644	edit dl rm
perlos400.pod	4618	0644	edit dl rm
perlothrtut.pod	40657	0644	edit dl rm
perlpacktut.pod	51047	0644	edit dl rm
perlperf.pod	51328	0644	edit dl rm
perlplan9.pod	5125	0644	edit dl rm
perlpod.pod	21626	0644	edit dl rm
perlpodspec.pod	67792	0644	edit dl rm
perlport.pod	86302	0644	edit dl rm
perlpragma.pod	4320	0644	edit dl rm
perlqnx.pod	4246	0644	edit dl rm
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perlrecharclass.pod	21909	0644	edit dl rm
perlref.pod	26465	0644	edit dl rm
perlreftut.pod	18670	0644	edit dl rm
perlreguts.pod	36877	0644	edit dl rm
perlrepository.pod	23453	0644	edit dl rm
perlrequick.pod	17617	0644	edit dl rm
perlreref.pod	11996	0644	edit dl rm
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perlriscos.pod	1511	0644	edit dl rm
perlrun.pod	49928	0644	edit dl rm
perlsec.pod	23542	0644	edit dl rm
perlsolaris.pod	29131	0644	edit dl rm
perlstyle.pod	8618	0644	edit dl rm
perlsub.pod	54222	0644	edit dl rm
perlsymbian.pod	16222	0644	edit dl rm
perlsyn.pod	31090	0644	edit dl rm
perlthrtut.pod	46510	0644	edit dl rm
perltie.pod	36665	0644	edit dl rm
perltoc.pod	642987	0644	edit dl rm
perltodo.pod	48360	0644	edit dl rm
perltooc.pod	51425	0644	edit dl rm
perltoot.pod	68625	0644	edit dl rm
perltrap.pod	41151	0644	edit dl rm
perltru64.pod	7736	0644	edit dl rm
perltw.pod	5384	0644	edit dl rm
perlunicode.pod	56169	0644	edit dl rm
perlunifaq.pod	12878	0644	edit dl rm
perluniintro.pod	32973	0644	edit dl rm
perlunitut.pod	7907	0644	edit dl rm
perlutil.pod	9881	0644	edit dl rm
perluts.pod	3180	0644	edit dl rm
perlvar.pod	59133	0644	edit dl rm
perlvmesa.pod	3952	0644	edit dl rm
perlvms.pod	52545	0644	edit dl rm
perlvos.pod	5567	0644	edit dl rm
perlwin32.pod	40809	0644	edit dl rm
perlxs.pod	74194	0644	edit dl rm
perlxstut.pod	49670	0644	edit dl rm

Edit: /usr/share/perl5/pod/perlrepository.pod (23453B)

=for comment
Consistent formatting of this file is achieved with:
  perl ./Porting/podtidy pod/perlrepository.pod

=head1 NAME

perlrepository - Using the Perl source repository

=head1 SYNOPSIS

All of Perl's source code is kept centrally in a Git repository at
I<perl5.git.perl.org>. The repository contains many Perl revisions from
Perl 1 onwards and all the revisions from Perforce, the version control
system we were using previously. This repository is accessible in
different ways.

The full repository takes up about 80MB of disk space. A check out of
the blead branch (that is, the main development branch, which contains
bleadperl, the development version of perl 5) takes up about 160MB of
disk space (including the repository). A build of bleadperl takes up
about 200MB (including the repository and the check out).

=head1 GETTING ACCESS TO THE REPOSITORY

=head2 READ ACCESS VIA THE WEB

You may access the repository over the web. This allows you to browse
the tree, see recent commits, subscribe to RSS feeds for the changes,
search for particular commits and more. You may access it at:

http://perl5.git.perl.org/perl.git

A mirror of the repository is found at:

http://github.com/github/perl

=head2 READ ACCESS VIA GIT

You will need a copy of Git for your computer. You can fetch a copy of
the repository using the Git protocol (which uses port 9418):

git clone git://perl5.git.perl.org/perl.git perl-git

This clones the repository and makes a local copy in the F<perl-git>
directory.

If your local network does not allow you to use port 9418, then you can
fetch a copy of the repository over HTTP (this is slower):

git clone http://perl5.git.perl.org/perl.git perl-http

This clones the repository and makes a local copy in the F<perl-http>
directory.

=head2 WRITE ACCESS TO THE REPOSITORY

If you are a committer, then you can fetch a copy of the repository
that you can push back on with:

git clone ssh://perl5.git.perl.org/gitroot/perl.git perl-ssh

This clones the repository and makes a local copy in the F<perl-ssh>
directory.

If you cloned using the git protocol, which is faster than ssh, then
you will need to modify your config in order to enable pushing. Edit
F<.git/config> where you will see something like:

[remote "origin"]
  url = git://perl5.git.perl.org/perl.git

change that to something like this:

[remote "origin"]
  url = ssh://perl5.git.perl.org/gitroot/perl.git

NOTE: there are symlinks set up so that the /gitroot is optional and
since SSH is the default protocol you can actually shorten the "url" to
C<perl5.git.perl.org:/perl.git>.

You can also set up your user name and e-mail address. For example

% git config user.name "Leon Brocard"
  % git config user.email acme@astray.com

It is also possible to keep C<origin> as a git remote, and add a new
remote for ssh access:

% git remote add camel perl5.git.perl.org:/perl.git

This allows you to update your local repository by pulling from
C<origin>, which is faster and doesn't require you to authenticate, and
to push your changes back with the C<camel> remote:

% git fetch camel
  % git push camel

The C<fetch> command just updates the C<camel> refs, as the objects
themselves should have been fetched when pulling from C<origin>.

The committers have access to 2 servers that serve perl5.git.perl.org.
One is camel.booking.com, which is the 'master' repository. The
perl5.git.perl.org IP address also lives on this machine. The second
one is dromedary.booking.com, which can be used for general testing and
development. Dromedary syncs the git tree from camel every few minutes,
you should not push there. Both machines also have a full CPAN mirror.
To share files with the general public, dromedary serves your
~/public_html/ as http://users.perl5.git.perl.org/~yourlogin/

=head1 OVERVIEW OF THE REPOSITORY

Once you have changed into the repository directory, you can inspect
it.

After a clone the repository will contain a single local branch, which
will be the current branch as well, as indicated by the asterisk.

% git branch
  * blead

Using the -a switch to C<branch> will also show the remote tracking
branches in the repository:

% git branch -a
  * blead
    origin/HEAD
    origin/blead
  ...

The branches that begin with "origin" correspond to the "git remote"
that you cloned from (which is named "origin"). Each branch on the
remote will be exactly tracked by theses branches. You should NEVER do
work on these remote tracking branches. You only ever do work in a
local branch. Local branches can be configured to automerge (on pull)
from a designated remote tracking branch. This is the case with the
default branch C<blead> which will be configured to merge from the
remote tracking branch C<origin/blead>.

You can see recent commits:

% git log

And pull new changes from the repository, and update your local
repository (must be clean first)

% git pull

Assuming we are on the branch C<blead> immediately after a pull, this
command would be more or less equivalent to:

% git fetch
  % git merge origin/blead

In fact if you want to update your local repository without touching
your working directory you do:

% git fetch

And if you want to update your remote-tracking branches for all defined
remotes simultaneously you can do

% git remote update

Neither of these last two commands will update your working directory,
however both will update the remote-tracking branches in your
repository.

To switch to another branch:

% git checkout origin/maint-5.8-dor

To make a local branch of a remote branch:

% git checkout -b maint-5.10 origin/maint-5.10

To switch back to blead:

% git checkout blead

=head2 FINDING OUT YOUR STATUS

The most common git command you will use will probably be

% git status

This command will produce as output a description of the current state
of the repository, including modified files and unignored untracked
files, and in addition it will show things like what files have been
staged for the next commit, and usually some useful information about
how to change things. For instance the following:

$ git status
  # On branch blead
  # Your branch is ahead of 'origin/blead' by 1 commit.
  #
  # Changes to be committed:
  #   (use "git reset HEAD <file>..." to unstage)
  #
  #       modified:   pod/perlrepository.pod
  #
  # Changed but not updated:
  #   (use "git add <file>..." to update what will be committed)
  #
  #       modified:   pod/perlrepository.pod
  #
  # Untracked files:
  #   (use "git add <file>..." to include in what will be committed)
  #
  #       deliberate.untracked

This shows that there were changes to this document staged for commit,
and that there were further changes in the working directory not yet
staged. It also shows that there was an untracked file in the working
directory, and as you can see shows how to change all of this. It also
shows that there is one commit on the working branch C<blead> which has
not been pushed to the C<origin> remote yet. B<NOTE>: that this output
is also what you see as a template if you do not provide a message to
C<git commit>.

Assuming we commit all the mentioned changes above:

% git commit -a -m'explain git status and stuff about remotes'
  Created commit daf8e63: explain git status and stuff about remotes
   1 files changed, 83 insertions(+), 3 deletions(-)

We can re-run git status and see something like this:

% git status
  # On branch blead
  # Your branch is ahead of 'origin/blead' by 2 commits.
  #
  # Untracked files:
  #   (use "git add <file>..." to include in what will be committed)
  #
  #       deliberate.untracked
  nothing added to commit but untracked files present (use "git add" to track)

When in doubt, before you do anything else, check your status and read
it carefully, many questions are answered directly by the git status
output.

=head1 SUBMITTING A PATCH

If you have a patch in mind for Perl, you should first get a copy of
the repository:

% git clone git://perl5.git.perl.org/perl.git perl-git

Then change into the directory:

% cd perl-git

Alternatively, if you already have a Perl repository, you should ensure
that you're on the I<blead> branch, and your repository is up to date:

% git checkout blead
  % git pull

It's preferable to patch against the latest blead version, since this
is where new development occurs for all changes other than critical bug
fixes.  Critical bug fix patches should be made against the relevant
maint branches, or should be submitted with a note indicating all the
branches where the fix should be applied.

Now that we have everything up to date, we need to create a temporary
new branch for these changes and switch into it:

% git checkout -b orange

which is the short form of

% git branch orange
  % git checkout orange

Then make your changes. For example, if Leon Brocard changes his name
to Orange Brocard, we should change his name in the AUTHORS file:

% perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS

You can see what files are changed:

% git status
  # On branch orange
  # Changes to be committed:
  #   (use "git reset HEAD <file>..." to unstage)
  #
  #	modified:   AUTHORS
  #

And you can see the changes:

% git diff
  diff --git a/AUTHORS b/AUTHORS
  index 293dd70..722c93e 100644
  --- a/AUTHORS
  +++ b/AUTHORS
  @@ -541,7 +541,7 @@    Lars Hecking                   <lhecking@nmrc.ucc.ie>
   Laszlo Molnar                  <laszlo.molnar@eth.ericsson.se>
   Leif Huhn                      <leif@hale.dkstat.com>
   Len Johnson                    <lenjay@ibm.net>
  -Leon Brocard                   <acme@astray.com>
  +Orange Brocard                 <acme@astray.com>
   Les Peters                     <lpeters@aol.net>
   Lesley Binks                   <lesley.binks@gmail.com>
   Lincoln D. Stein               <lstein@cshl.org>

Now commit your change locally:

% git commit -a -m 'Rename Leon Brocard to Orange Brocard'
  Created commit 6196c1d: Rename Leon Brocard to Orange Brocard
   1 files changed, 1 insertions(+), 1 deletions(-)

You can examine your last commit with:

% git show HEAD

and if you are not happy with either the description or the patch
itself you can fix it up by editing the files once more and then issue:

% git commit -a --amend

Now you should create a patch file for all your local changes:

% git format-patch origin
  0001-Rename-Leon-Brocard-to-Orange-Brocard.patch

You should now send an email to perl5-porters@perl.org with a
description of your changes, and include this patch file as an
attachment.

If you want to delete your temporary branch, you may do so with:

% git checkout blead
  % git branch -d orange
  error: The branch 'orange' is not an ancestor of your current HEAD.
  If you are sure you want to delete it, run 'git branch -D orange'.
  % git branch -D orange
  Deleted branch orange.

=head2 A note on derived files

Be aware that many files in the distribution are derivative--avoid
patching them, because git won't see the changes to them, and the build
process will overwrite them. Patch the originals instead.  Most
utilities (like perldoc) are in this category, i.e. patch
utils/perldoc.PL rather than utils/perldoc. Similarly, don't create
patches for files under $src_root/ext from their copies found in
$install_root/lib.  If you are unsure about the proper location of a
file that may have gotten copied while building the source
distribution, consult the C<MANIFEST>.

=head2 A note on binary files

Since the patch(1) utility cannot deal with binary files, it's
important that you either avoid the use of binary files in your patch,
generate the files dynamically, or that you encode any binary files
using the F<uupacktool.pl> utility.

Assuming you needed to include a gzip-encoded file for a module's test
suite, you might do this as follows using the F<uupacktool.pl> utility:

$ perl uupacktool.pl -v -p -D lib/Some/Module/t/src/t.gz
    Writing lib/Some/Module/t/src/t.gz into lib/Some/Module/t/src/t.gz.packed

This will replace the C<t.gz> file with an encoded counterpart. During
C<make test>, before any tests are run, perl's Makefile will restore
all the C<.packed> files mentioned in the MANIFEST to their original
name. This means that the test suite does not need to be aware of this
packing scheme and will not need to be altered.

=head2 Getting your patch accepted

The first thing you should include with your patch is a description of
the problem that the patch corrects.  If it is a code patch (rather
than a documentation patch) you should also include a small test case
that illustrates the bug (a patch to an existing test file is
preferred).

If you are submitting a code patch there are several other things that
you need to do.

=over 4

=item Comments, Comments, Comments

Be sure to adequately comment your code.  While commenting every line
is unnecessary, anything that takes advantage of side effects of
operators, that creates changes that will be felt outside of the
function being patched, or that others may find confusing should be
documented.  If you are going to err, it is better to err on the side
of adding too many comments than too few.

=item Style

In general, please follow the particular style of the code you are
patching.

In particular, follow these general guidelines for patching Perl
sources:

8-wide tabs (no exceptions!)
    4-wide indents for code, 2-wide indents for nested CPP #defines
    try hard not to exceed 79-columns
    ANSI C prototypes
    uncuddled elses and "K&R" style for indenting control constructs
    no C++ style (//) comments
    mark places that need to be revisited with XXX (and revisit often!)
    opening brace lines up with "if" when conditional spans multiple
        lines; should be at end-of-line otherwise
    in function definitions, name starts in column 0 (return value is on
        previous line)
    single space after keywords that are followed by parens, no space
        between function name and following paren
    avoid assignments in conditionals, but if they're unavoidable, use
        extra paren, e.g. "if (a && (b = c)) ..."
    "return foo;" rather than "return(foo);"
    "if (!foo) ..." rather than "if (foo == FALSE) ..." etc.

=item Testsuite

When submitting a patch you should make every effort to also include an
addition to perl's regression tests to properly exercise your patch. 
Your testsuite additions should generally follow these guidelines
(courtesy of Gurusamy Sarathy <gsar@activestate.com>):

Know what you're testing.  Read the docs, and the source.
    Tend to fail, not succeed.
    Interpret results strictly.
    Use unrelated features (this will flush out bizarre interactions).
    Use non-standard idioms (otherwise you are not testing TIMTOWTDI).
    Avoid using hardcoded test numbers whenever possible (the
      EXPECTED/GOT found in t/op/tie.t is much more maintainable,
      and gives better failure reports).
    Give meaningful error messages when a test fails.
    Avoid using qx// and system() unless you are testing for them.  If you
      do use them, make sure that you cover _all_ perl platforms.
    Unlink any temporary files you create.
    Promote unforeseen warnings to errors with $SIG{__WARN__}.
    Be sure to use the libraries and modules shipped with the version
      being tested, not those that were already installed.
    Add comments to the code explaining what you are testing for.
    Make updating the '1..42' string unnecessary.  Or make sure that
      you update it.
    Test _all_ behaviors of a given operator, library, or function:
      - All optional arguments
      - Return values in various contexts (boolean, scalar, list, lvalue)
      - Use both global and lexical variables
      - Don't forget the exceptional, pathological cases.

=back

=head1 ACCEPTING A PATCH

If you have received a patch file generated using the above section,
you should try out the patch.

First we need to create a temporary new branch for these changes and
switch into it:

% git checkout -b experimental

Patches that were formatted by C<git format-patch> are applied with
C<git am>:

% git am 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
  Applying Rename Leon Brocard to Orange Brocard

If just a raw diff is provided, it is also possible use this two-step
process:

% git apply bugfix.diff
  % git commit -a -m "Some fixing" --author="That Guy <that.guy@internets.com>"

Now we can inspect the change:

% git show HEAD
  commit b1b3dab48344cff6de4087efca3dbd63548ab5e2
  Author: Leon Brocard <acme@astray.com>
  Date:   Fri Dec 19 17:02:59 2008 +0000

Rename Leon Brocard to Orange Brocard

diff --git a/AUTHORS b/AUTHORS
  index 293dd70..722c93e 100644
  --- a/AUTHORS
  +++ b/AUTHORS
  @@ -541,7 +541,7 @@ Lars Hecking                        <lhecking@nmrc.ucc.ie>
   Laszlo Molnar                  <laszlo.molnar@eth.ericsson.se>
   Leif Huhn                      <leif@hale.dkstat.com>
   Len Johnson                    <lenjay@ibm.net>
  -Leon Brocard                   <acme@astray.com>
  +Orange Brocard                 <acme@astray.com>
   Les Peters                     <lpeters@aol.net>
   Lesley Binks                   <lesley.binks@gmail.com>
   Lincoln D. Stein               <lstein@cshl.org>

If you are a committer to Perl and you think the patch is good, you can
then merge it into blead then push it out to the main repository:

% git checkout blead
  % git merge experimental
  % git push

If you want to delete your temporary branch, you may do so with:

% git checkout blead
  % git branch -d experimental
  error: The branch 'experimental' is not an ancestor of your current HEAD.
  If you are sure you want to delete it, run 'git branch -D experimental'.
  % git branch -D experimental
  Deleted branch experimental.

=head1 CLEANING A WORKING DIRECTORY

The command C<git clean> can with varying arguments be used as a
replacement for C<make clean>.

To reset your working directory to a pristine condition you can do:

git clean -dxf

However, be aware this will delete ALL untracked content. You can use

git clean -Xf

to remove all ignored untracked files, such as build and test
byproduct, but leave any  manually created files alone.

If you only want to cancel some uncommitted edits, you can use C<git
checkout> and give it a list of files to be reverted, or C<git checkout
-f> to revert them all.

If you want to cancel one or several commits, you can use C<git reset>.

=head1 BISECTING

C<git> provides a built-in way to determine, with a binary search in
the history, which commit should be blamed for introducing a given bug.

Suppose that we have a script F<~/testcase.pl> that exits with C<0>
when some behaviour is correct, and with C<1> when it's faulty. We need
an helper script that automates building C<perl> and running the
testcase:

% cat ~/run
  #!/bin/sh
  git clean -dxf
  # If you can use ccache, add -Dcc=ccache\ gcc -Dld=gcc to the Configure line
  sh Configure -des -Dusedevel -Doptimize="-g"
  test -f config.sh || exit 125
  # Correct makefile for newer GNU gcc
  perl -ni -we 'print unless /<(?:built-in|command)/' makefile x2p/makefile
  # if you just need miniperl, replace test_prep with miniperl
  make -j4 test_prep
  -x ./perl || exit 125
  ./perl -Ilib ~/testcase.pl
  ret=$?
  git clean -dxf
  exit $ret

This script may return C<125> to indicate that the corresponding commit
should be skipped. Otherwise, it returns the status of
F<~/testcase.pl>.

We first enter in bisect mode with:

% git bisect start

For example, if the bug is present on C<HEAD> but wasn't in 5.10.0,
C<git> will learn about this when you enter:

% git bisect bad
  % git bisect good perl-5.10.0
  Bisecting: 853 revisions left to test after this

This results in checking out the median commit between C<HEAD> and
C<perl-5.10.0>. We can then run the bisecting process with:

% git bisect run ~/run

When the first bad commit is isolated, C<git bisect> will tell you so:

ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 is first bad commit
  commit ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5
  Author: Dave Mitchell <davem@fdisolutions.com>
  Date:   Sat Feb 9 14:56:23 2008 +0000

[perl #49472] Attributes + Unknown Error
      ...

bisect run success

You can peek into the bisecting process with C<git bisect log> and
C<git bisect visualize>. C<git bisect reset> will get you out of bisect
mode.

Please note that the first C<good> state must be an ancestor of the
first C<bad> state. If you want to search for the commit that I<solved>
some bug, you have to negate your test case (i.e. exit with C<1> if OK
and C<0> if not) and still mark the lower bound as C<good> and the
upper as C<bad>. The "first bad commit" has then to be understood as
the "first commit where the bug is solved".

C<git help bisect> has much more information on how you can tweak your
binary searches.

=head1 SUBMITTING A PATCH VIA GITHUB

GitHub is a website that makes it easy to fork and publish projects
with Git. First you should set up a GitHub account and log in.

Perl's git repository is mirrored on GitHub at this page:

http://github.com/github/perl/tree/blead

Visit the page and click the "fork" button. This clones the Perl git
repository for you and provides you with "Your Clone URL" from which
you should clone:

% git clone git@github.com:USERNAME/perl.git perl-github

We shall make the same patch as above, creating a new branch:

% cd perl-github
  % git remote add upstream git://github.com/github/perl.git
  % git pull upstream blead
  % git checkout -b orange
  % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
  % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
  % git push origin orange

The orange branch has been pushed to GitHub, so you should now send an
email to perl5-porters@perl.org with a description of your changes and
the following information:

http://github.com/USERNAME/perl/tree/orange
  git@github.com:USERNAME/perl.git branch orange

=head1 MERGING FROM A BRANCH VIA GITHUB

If someone has provided a branch via GitHub and you are a committer,
you should use the following in your perl-ssh directory:

% git remote add dandv git://github.com/dandv/perl.git
  % git fetch

Now you can see the differences between the branch and blead:

% git diff dandv/blead

And you can see the commits:

% git log dandv/blead

If you approve of a specific commit, you can cherry pick it:

% git cherry-pick 3adac458cb1c1d41af47fc66e67b49c8dec2323f

Or you could just merge the whole branch if you like it all:

% git merge dandv/blead

And then push back to the repository:

% git push

=head1 COMMITTING TO MAINTENANCE VERSIONS

Maintenance versions should only be altered to add critical bug fixes.

To commit to a maintenance version of perl, you need to create a local
tracking branch:

% git checkout --track -b maint-5.005 origin/maint-5.005

This creates a local branch named C<maint-5.005>, which tracks the
remote branch C<origin/maint-5.005>. Then you can pull, commit, merge
and push as before.

You can also cherry-pick commits from blead and another branch, by
using the C<git cherry-pick> command. It is recommended to use the
B<-x> option to C<git cherry-pick> in order to record the SHA1 of the
original commit in the new commit message.

=head1 SEE ALSO

The git documentation, accessible via C<git help command>.

cmd: