This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
fetching from e.g. github requires a repo name
[perl5.git] / pod / perlrepository.pod
CommitLineData
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1=for comment
2Consistent formatting of this file is achieved with:
3 perl ./Porting/podtidy pod/perlrepository.pod
4
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5=head1 NAME
6
7perlrepository - Using the Perl source repository
8
9=head1 SYNOPSIS
10
dc3c3040 11All of Perl's source code is kept centrally in a Git repository at
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12I<perl5.git.perl.org>. The repository contains many Perl revisions from
13Perl 1 onwards and all the revisions from Perforce, the version control
14system we were using previously. This repository is accessible in
15different ways.
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16
17The full repository takes up about 80MB of disk space. A check out of
7f4ffa9d 18the blead branch (that is, the main development branch, which contains
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19bleadperl, the development version of perl 5) takes up about 160MB of
20disk space (including the repository). A build of bleadperl takes up
21about 200MB (including the repository and the check out).
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22
23=head1 GETTING ACCESS TO THE REPOSITORY
24
25=head2 READ ACCESS VIA THE WEB
26
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27You may access the repository over the web. This allows you to browse
28the tree, see recent commits, subscribe to RSS feeds for the changes,
29search for particular commits and more. You may access it at:
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30
31 http://perl5.git.perl.org/perl.git
32
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33A mirror of the repository is found at:
34
35 http://github.com/github/perl
36
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37=head2 READ ACCESS VIA GIT
38
39You will need a copy of Git for your computer. You can fetch a copy of
40the repository using the Git protocol (which uses port 9418):
41
e0b2b458 42 % git clone git://perl5.git.perl.org/perl.git perl-git
d7dd28b6 43
f755e97d 44This clones the repository and makes a local copy in the F<perl-git>
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45directory.
46
47If your local network does not allow you to use port 9418, then you can
cf5e7595 48fetch a copy of the repository over HTTP (this is at least 4x slower):
d7dd28b6 49
e0b2b458 50 % git clone http://perl5.git.perl.org/perl.git perl-http
d7dd28b6 51
f755e97d 52This clones the repository and makes a local copy in the F<perl-http>
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53directory.
54
55=head2 WRITE ACCESS TO THE REPOSITORY
56
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57If you are a committer, then you can fetch a copy of the repository
58that you can push back on with:
d7dd28b6 59
e0b2b458 60 % git clone ssh://perl5.git.perl.org/perl.git perl-ssh
d7dd28b6 61
8f718e95 62This clones the repository and makes a local copy in the F<perl-ssh>
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63directory.
64
c26da522 65If you cloned using the git protocol, which is faster than ssh, then
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66you will need to modify the URL for the origin remote to enable
67pushing. To do that edit F<.git/config> with L<git-config(1)> like
68this:
1a0f15d5 69
e0b2b458 70 % git config remote.origin.url ssh://perl5.git.perl.org/perl.git
d7dd28b6 71
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72You can also set up your user name and e-mail address. Most people do
73this once globally in their F<~/.gitconfig> by doing something like:
184487f0 74
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75 % git config --global user.name "Ævar Arnfjörð Bjarmason"
76 % git config --global user.email avarab@gmail.com
77
78However if you'd like to override that just for perl then execute then
79execute something like the following in F<perl-git>:
80
81 % git config user.email avar@cpan.org
184487f0 82
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83It is also possible to keep C<origin> as a git remote, and add a new
84remote for ssh access:
f6c12373 85
dc3c3040 86 % git remote add camel perl5.git.perl.org:/perl.git
f6c12373 87
6acba58e 88This allows you to update your local repository by pulling from
f755e97d 89C<origin>, which is faster and doesn't require you to authenticate, and
6acba58e 90to push your changes back with the C<camel> remote:
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91
92 % git fetch camel
93 % git push camel
94
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95The C<fetch> command just updates the C<camel> refs, as the objects
96themselves should have been fetched when pulling from C<origin>.
f6c12373 97
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98=head2 A NOTE ON CAMEL AND DROMEDARY
99
100The committers have SSH access to the two servers that serve
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101C<perl5.git.perl.org>. One is C<perl5.git.perl.org> itself (I<camel>),
102which is the 'master' repository. The second one is
103C<users.perl5.git.perl.org> (I<dromedary>), which can be used for
104general testing and development. Dromedary syncs the git tree from
105camel every few minutes, you should not push there. Both machines also
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106have a full CPAN mirror in /srv/CPAN, please use this. To share files
107with the general public, dromedary serves your ~/public_html/ as
333f8875 108C<http://users.perl5.git.perl.org/~yourlogin/>
b47aa495 109
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110These hosts have fairly strict firewalls to the outside. Outgoing, only
111rsync, ssh and git are allowed. For http and ftp, you can use
112http://webproxy:3128 as proxy. Incoming, the firewall tries to detect
113attacks and blocks IP addresses with suspicious activity. This
114sometimes (but very rarely) has false positives and you might get
115blocked. The quickest way to get unblocked is to notify the admins.
116
117These two boxes are owned, hosted, and operated by booking.com. You can
118reach the sysadmins in #p5p on irc.perl.org or via mail to
119C<perl5-porters@perl.org>
120
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121=head1 OVERVIEW OF THE REPOSITORY
122
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123Once you have changed into the repository directory, you can inspect
124it.
d7dd28b6 125
39219fd3 126After a clone the repository will contain a single local branch, which
50eca761 127will be the current branch as well, as indicated by the asterisk.
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128
129 % git branch
130 * blead
131
f755e97d 132Using the -a switch to C<branch> will also show the remote tracking
6acba58e 133branches in the repository:
39219fd3 134
d9847473 135 % git branch -a
09081495 136 * blead
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137 origin/HEAD
138 origin/blead
139 ...
140
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141The branches that begin with "origin" correspond to the "git remote"
142that you cloned from (which is named "origin"). Each branch on the
143remote will be exactly tracked by theses branches. You should NEVER do
144work on these remote tracking branches. You only ever do work in a
145local branch. Local branches can be configured to automerge (on pull)
146from a designated remote tracking branch. This is the case with the
147default branch C<blead> which will be configured to merge from the
148remote tracking branch C<origin/blead>.
39219fd3 149
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150You can see recent commits:
151
c2cf2042 152 % git log
d7dd28b6 153
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154And pull new changes from the repository, and update your local
155repository (must be clean first)
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156
157 % git pull
09081495 158
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159Assuming we are on the branch C<blead> immediately after a pull, this
160command would be more or less equivalent to:
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161
162 % git fetch
163 % git merge origin/blead
164
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165In fact if you want to update your local repository without touching
166your working directory you do:
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167
168 % git fetch
169
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170And if you want to update your remote-tracking branches for all defined
171remotes simultaneously you can do
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172
173 % git remote update
174
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175Neither of these last two commands will update your working directory,
176however both will update the remote-tracking branches in your
177repository.
39219fd3 178
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179To switch to another branch:
180
181 % git checkout origin/maint-5.8-dor
182
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183To make a local branch of a remote branch:
184
185 % git checkout -b maint-5.10 origin/maint-5.10
186
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187To switch back to blead:
188
189 % git checkout blead
c2cf2042 190
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191=head2 FINDING OUT YOUR STATUS
192
193The most common git command you will use will probably be
194
195 % git status
196
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197This command will produce as output a description of the current state
198of the repository, including modified files and unignored untracked
199files, and in addition it will show things like what files have been
200staged for the next commit, and usually some useful information about
201how to change things. For instance the following:
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202
203 $ git status
204 # On branch blead
205 # Your branch is ahead of 'origin/blead' by 1 commit.
206 #
207 # Changes to be committed:
208 # (use "git reset HEAD <file>..." to unstage)
209 #
210 # modified: pod/perlrepository.pod
211 #
212 # Changed but not updated:
213 # (use "git add <file>..." to update what will be committed)
214 #
215 # modified: pod/perlrepository.pod
216 #
217 # Untracked files:
218 # (use "git add <file>..." to include in what will be committed)
219 #
220 # deliberate.untracked
221
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222This shows that there were changes to this document staged for commit,
223and that there were further changes in the working directory not yet
224staged. It also shows that there was an untracked file in the working
225directory, and as you can see shows how to change all of this. It also
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226shows that there is one commit on the working branch C<blead> which has
227not been pushed to the C<origin> remote yet. B<NOTE>: that this output
228is also what you see as a template if you do not provide a message to
229C<git commit>.
7f6effc7 230
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231Assuming that you'd like to commit all the changes you've just made as a
232a single atomic unit, run this command:
233
234 % git commit -a
235
236(That C<-a> tells git to add every file you've changed to this commit.
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237New files aren't automatically added to your commit when you use C<commit
238-a> If you want to add files or to commit some, but not all of your
239changes, have a look at the documentation for C<git add>.)
bdaf0bc6 240
e9360695 241Git will start up your favorite text editor, so that you can craft a
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242commit message for your change. See L</Commit message> below for more
243information about what makes a good commit message.
244
245Once you've finished writing your commit message and exited your editor,
246git will write your change to disk and tell you something like this:
7f6effc7 247
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248 Created commit daf8e63: explain git status and stuff about remotes
249 1 files changed, 83 insertions(+), 3 deletions(-)
250
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251
252If you re-run C<git status>, you should see something like this:
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253
254 % git status
255 # On branch blead
256 # Your branch is ahead of 'origin/blead' by 2 commits.
257 #
258 # Untracked files:
259 # (use "git add <file>..." to include in what will be committed)
260 #
261 # deliberate.untracked
262 nothing added to commit but untracked files present (use "git add" to track)
263
39219fd3 264
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265When in doubt, before you do anything else, check your status and read
266it carefully, many questions are answered directly by the git status
267output.
39219fd3 268
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269=head1 SUBMITTING A PATCH
270
271If you have a patch in mind for Perl, you should first get a copy of
272the repository:
273
274 % git clone git://perl5.git.perl.org/perl.git perl-git
275
276Then change into the directory:
277
278 % cd perl-git
279
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280Alternatively, if you already have a Perl repository, you should ensure
281that you're on the I<blead> branch, and your repository is up to date:
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282
283 % git checkout blead
284 % git pull
285
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286It's preferable to patch against the latest blead version, since this
287is where new development occurs for all changes other than critical bug
288fixes. Critical bug fix patches should be made against the relevant
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289maint branches, or should be submitted with a note indicating all the
290branches where the fix should be applied.
a44f43ac 291
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292Now that we have everything up to date, we need to create a temporary
293new branch for these changes and switch into it:
b1fccde5 294
a9b05323 295 % git checkout -b orange
23f8d33e 296
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297which is the short form of
298
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299 % git branch orange
300 % git checkout orange
301
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302Creating a topic branch makes it easier for the maintainers to rebase
303or merge back into the master blead for a more linear history. If you
304don't work on a topic branch the maintainer has to manually cherry
305pick your changes onto blead before they can be applied.
306
307That'll get you scolded on perl5-porters, so don't do that. Be
308Awesome.
309
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310Then make your changes. For example, if Leon Brocard changes his name
311to Orange Brocard, we should change his name in the AUTHORS file:
312
313 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
314
315You can see what files are changed:
316
317 % git status
f755e97d 318 # On branch orange
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319 # Changes to be committed:
320 # (use "git reset HEAD <file>..." to unstage)
321 #
2699d634 322 # modified: AUTHORS
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323 #
324
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325And you can see the changes:
326
327 % git diff
328 diff --git a/AUTHORS b/AUTHORS
329 index 293dd70..722c93e 100644
330 --- a/AUTHORS
331 +++ b/AUTHORS
7df2e4bc 332 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
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333 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
334 Leif Huhn <leif@hale.dkstat.com>
335 Len Johnson <lenjay@ibm.net>
336 -Leon Brocard <acme@astray.com>
337 +Orange Brocard <acme@astray.com>
338 Les Peters <lpeters@aol.net>
339 Lesley Binks <lesley.binks@gmail.com>
340 Lincoln D. Stein <lstein@cshl.org>
341
342Now commit your change locally:
343
dc3c3040 344 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
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345 Created commit 6196c1d: Rename Leon Brocard to Orange Brocard
346 1 files changed, 1 insertions(+), 1 deletions(-)
347
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348You can examine your last commit with:
349
350 % git show HEAD
351
352and if you are not happy with either the description or the patch
c26da522 353itself you can fix it up by editing the files once more and then issue:
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354
355 % git commit -a --amend
356
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357Now you should create a patch file for all your local changes:
358
2af192ee 359 % git format-patch origin
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360 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
361
362You should now send an email to perl5-porters@perl.org with a
dc3c3040 363description of your changes, and include this patch file as an
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364attachment. (See the next section for how to configure and use git to
365send these emails for you.)
c2cf2042 366
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367If you want to delete your temporary branch, you may do so with:
368
369 % git checkout blead
370 % git branch -d orange
371 error: The branch 'orange' is not an ancestor of your current HEAD.
372 If you are sure you want to delete it, run 'git branch -D orange'.
373 % git branch -D orange
374 Deleted branch orange.
7df2e4bc 375
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376=head2 Using git to send patch emails
377
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378In your ~/git/perl repository, set the destination email to the
379perl5-porters mailing list.
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380
381 $ git config sendemail.to perl5-porters@perl.org
382
383Then you can use git directly to send your patch emails:
384
385 $ git send-email 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
386
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387You may need to set some configuration variables for your particular
388email service provider. For example, to set your global git config to
389send email via a gmail account:
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390
391 $ git config --global sendemail.smtpserver smtp.gmail.com
392 $ git config --global sendemail.smtpssl 1
393 $ git config --global sendemail.smtpuser YOURUSERNAME@gmail.com
394
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395With this configuration, you will be prompted for your gmail password
396when you run 'git send-email'. You can also configure
397C<sendemail.smtppass> with your password if you don't care about having
398your password in the .gitconfig file.
2d5f1d01 399
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400=head2 A note on derived files
401
402Be aware that many files in the distribution are derivative--avoid
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403patching them, because git won't see the changes to them, and the build
404process will overwrite them. Patch the originals instead. Most
405utilities (like perldoc) are in this category, i.e. patch
406utils/perldoc.PL rather than utils/perldoc. Similarly, don't create
407patches for files under $src_root/ext from their copies found in
408$install_root/lib. If you are unsure about the proper location of a
409file that may have gotten copied while building the source
410distribution, consult the C<MANIFEST>.
a44f43ac 411
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412As a special case, several files are regenerated by 'make regen' if
413your patch alters C<embed.fnc>. These are needed for compilation, but
414are included in the distribution so that you can build perl without
415needing another perl to generate the files. You must test with these
416regenerated files, but it is preferred that you instead note that
417'make regen is needed' in both the email and the commit message, and
418submit your patch without them. If you're submitting a series of
419patches, it might be best to submit the regenerated changes
420immediately after the source-changes that caused them, so as to have
421as little effect as possible on the bisectability of your patchset.
422
6e2cec71 423=for XXX
a44f43ac 424
6e2cec71 425What should we recommend about binary files now? Do we need anything?
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426
427=head2 Getting your patch accepted
428
bdaf0bc6 429If you are submitting a code patch there are several things that
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430you need to do.
431
432=over 4
433
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434=item Commit message
435
436As you craft each patch you intend to submit to the Perl core, it's
437important to write a good commit message.
438
439Your commit message should start with a description of the problem that
440the patch corrects or new functionality that the patch adds.
441
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442As a general rule of thumb, your commit message should let a programmer
443with a reasonable familiarity with the Perl core quickly understand what
444you were trying to do, how you were trying to do it and why the change
445matters to Perl.
446
447=over 4
448
449=item What
450
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451Your commit message should describe what part of the Perl core you're
452changing and what you expect your patch to do.
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453
454=item Why
455
456Perhaps most importantly, your commit message should describe why the
457change you are making is important. When someone looks at your change
458in six months or six years, your intent should be clear. If you're
459deprecating a feature with the intent of later simplifying another bit
460of code, say so. If you're fixing a performance problem or adding a new
461feature to support some other bit of the core, mention that.
462
463=item How
464
465While it's not necessary for documentation changes, new tests or
466trivial patches, it's often worth explaining how your change works.
467Even if it's clear to you today, it may not be clear to a porter next
468month or next year.
469
470=back
471
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472A commit message isn't intended to take the place of comments in your
473code. Commit messages should describe the change you made, while code
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474comments should describe the current state of the code. If you've just
475implemented a new feature, complete with doc, tests and well-commented
476code, a brief commit message will often suffice. If, however, you've
477just changed a single character deep in the parser or lexer, you might
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478need to write a small novel to ensure that future readers understand
479what you did and why you did it.
480
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481=item Comments, Comments, Comments
482
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483Be sure to adequately comment your code. While commenting every line
484is unnecessary, anything that takes advantage of side effects of
a44f43ac 485operators, that creates changes that will be felt outside of the
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486function being patched, or that others may find confusing should be
487documented. If you are going to err, it is better to err on the side
488of adding too many comments than too few.
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489
490=item Style
491
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492In general, please follow the particular style of the code you are
493patching.
a44f43ac 494
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495In particular, follow these general guidelines for patching Perl
496sources:
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497
498 8-wide tabs (no exceptions!)
499 4-wide indents for code, 2-wide indents for nested CPP #defines
500 try hard not to exceed 79-columns
501 ANSI C prototypes
502 uncuddled elses and "K&R" style for indenting control constructs
503 no C++ style (//) comments
504 mark places that need to be revisited with XXX (and revisit often!)
505 opening brace lines up with "if" when conditional spans multiple
506 lines; should be at end-of-line otherwise
507 in function definitions, name starts in column 0 (return value is on
508 previous line)
509 single space after keywords that are followed by parens, no space
510 between function name and following paren
511 avoid assignments in conditionals, but if they're unavoidable, use
512 extra paren, e.g. "if (a && (b = c)) ..."
513 "return foo;" rather than "return(foo);"
514 "if (!foo) ..." rather than "if (foo == FALSE) ..." etc.
515
516=item Testsuite
517
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518If your patch changes code (rather than just changing documentation) you
519should also include one or more test cases which illustrate the bug you're
520fixing or validate the new functionality you're adding. In general,
521you should update an existing test file rather than create a new one.
522
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523Your testsuite additions should generally follow these guidelines
524(courtesy of Gurusamy Sarathy <gsar@activestate.com>):
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525
526 Know what you're testing. Read the docs, and the source.
527 Tend to fail, not succeed.
528 Interpret results strictly.
529 Use unrelated features (this will flush out bizarre interactions).
530 Use non-standard idioms (otherwise you are not testing TIMTOWTDI).
531 Avoid using hardcoded test numbers whenever possible (the
532 EXPECTED/GOT found in t/op/tie.t is much more maintainable,
533 and gives better failure reports).
534 Give meaningful error messages when a test fails.
535 Avoid using qx// and system() unless you are testing for them. If you
536 do use them, make sure that you cover _all_ perl platforms.
537 Unlink any temporary files you create.
538 Promote unforeseen warnings to errors with $SIG{__WARN__}.
539 Be sure to use the libraries and modules shipped with the version
540 being tested, not those that were already installed.
541 Add comments to the code explaining what you are testing for.
542 Make updating the '1..42' string unnecessary. Or make sure that
543 you update it.
544 Test _all_ behaviors of a given operator, library, or function:
545 - All optional arguments
546 - Return values in various contexts (boolean, scalar, list, lvalue)
547 - Use both global and lexical variables
548 - Don't forget the exceptional, pathological cases.
549
550=back
551
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552=head1 ACCEPTING A PATCH
553
554If you have received a patch file generated using the above section,
555you should try out the patch.
556
557First we need to create a temporary new branch for these changes and
558switch into it:
559
a9b05323 560 % git checkout -b experimental
7df2e4bc 561
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562Patches that were formatted by C<git format-patch> are applied with
563C<git am>:
7df2e4bc 564
2af192ee 565 % git am 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
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566 Applying Rename Leon Brocard to Orange Brocard
567
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568If just a raw diff is provided, it is also possible use this two-step
569process:
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570
571 % git apply bugfix.diff
dc3c3040 572 % git commit -a -m "Some fixing" --author="That Guy <that.guy@internets.com>"
09645c26 573
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574Now we can inspect the change:
575
dc3c3040 576 % git show HEAD
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577 commit b1b3dab48344cff6de4087efca3dbd63548ab5e2
578 Author: Leon Brocard <acme@astray.com>
579 Date: Fri Dec 19 17:02:59 2008 +0000
580
581 Rename Leon Brocard to Orange Brocard
7df2e4bc 582
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583 diff --git a/AUTHORS b/AUTHORS
584 index 293dd70..722c93e 100644
585 --- a/AUTHORS
586 +++ b/AUTHORS
587 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
588 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
589 Leif Huhn <leif@hale.dkstat.com>
590 Len Johnson <lenjay@ibm.net>
591 -Leon Brocard <acme@astray.com>
592 +Orange Brocard <acme@astray.com>
593 Les Peters <lpeters@aol.net>
594 Lesley Binks <lesley.binks@gmail.com>
595 Lincoln D. Stein <lstein@cshl.org>
596
597If you are a committer to Perl and you think the patch is good, you can
75fb7651 598then merge it into blead then push it out to the main repository:
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599
600 % git checkout blead
d9847473 601 % git merge experimental
75fb7651 602 % git push
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603
604If you want to delete your temporary branch, you may do so with:
605
606 % git checkout blead
607 % git branch -d experimental
608 error: The branch 'experimental' is not an ancestor of your current HEAD.
609 If you are sure you want to delete it, run 'git branch -D experimental'.
610 % git branch -D experimental
611 Deleted branch experimental.
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612
613=head1 CLEANING A WORKING DIRECTORY
614
6acba58e 615The command C<git clean> can with varying arguments be used as a
dc3c3040 616replacement for C<make clean>.
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617
618To reset your working directory to a pristine condition you can do:
619
e0b2b458 620 % git clean -dxf
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621
622However, be aware this will delete ALL untracked content. You can use
623
e0b2b458 624 % git clean -Xf
b0d36535 625
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626to remove all ignored untracked files, such as build and test
627byproduct, but leave any manually created files alone.
b0d36535 628
0549aefb 629If you only want to cancel some uncommitted edits, you can use C<git
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630checkout> and give it a list of files to be reverted, or C<git checkout
631-f> to revert them all.
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632
633If you want to cancel one or several commits, you can use C<git reset>.
634
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635=head1 BISECTING
636
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637C<git> provides a built-in way to determine, with a binary search in
638the history, which commit should be blamed for introducing a given bug.
d82a90c1 639
6acba58e 640Suppose that we have a script F<~/testcase.pl> that exits with C<0>
bdaf0bc6 641when some behaviour is correct, and with C<1> when it's faulty. You need
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642an helper script that automates building C<perl> and running the
643testcase:
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644
645 % cat ~/run
646 #!/bin/sh
647 git clean -dxf
648 # If you can use ccache, add -Dcc=ccache\ gcc -Dld=gcc to the Configure line
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649 # if Encode is not needed for the test, you can speed up the bisect by
650 # excluding it from the runs with -Dnoextensions=Encode
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651 sh Configure -des -Dusedevel -Doptimize="-g"
652 test -f config.sh || exit 125
653 # Correct makefile for newer GNU gcc
654 perl -ni -we 'print unless /<(?:built-in|command)/' makefile x2p/makefile
655 # if you just need miniperl, replace test_prep with miniperl
656 make -j4 test_prep
68814ba4 657 [ -x ./perl ] || exit 125
d82a90c1 658 ./perl -Ilib ~/testcase.pl
c0d1ef72 659 ret=$?
7930c68b 660 [ $ret -gt 127 ] && ret=127
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661 git clean -dxf
662 exit $ret
d82a90c1 663
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664This script may return C<125> to indicate that the corresponding commit
665should be skipped. Otherwise, it returns the status of
666F<~/testcase.pl>.
d82a90c1 667
bdaf0bc6 668You first enter in bisect mode with:
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669
670 % git bisect start
671
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672For example, if the bug is present on C<HEAD> but wasn't in 5.10.0,
673C<git> will learn about this when you enter:
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674
675 % git bisect bad
676 % git bisect good perl-5.10.0
677 Bisecting: 853 revisions left to test after this
678
6acba58e 679This results in checking out the median commit between C<HEAD> and
bdaf0bc6 680C<perl-5.10.0>. You can then run the bisecting process with:
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681
682 % git bisect run ~/run
683
684When the first bad commit is isolated, C<git bisect> will tell you so:
685
686 ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 is first bad commit
687 commit ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5
688 Author: Dave Mitchell <davem@fdisolutions.com>
689 Date: Sat Feb 9 14:56:23 2008 +0000
690
9469eb4a 691 [perl #49472] Attributes + Unknown Error
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692 ...
693
694 bisect run success
695
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696You can peek into the bisecting process with C<git bisect log> and
697C<git bisect visualize>. C<git bisect reset> will get you out of bisect
698mode.
d82a90c1 699
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700Please note that the first C<good> state must be an ancestor of the
701first C<bad> state. If you want to search for the commit that I<solved>
702some bug, you have to negate your test case (i.e. exit with C<1> if OK
703and C<0> if not) and still mark the lower bound as C<good> and the
704upper as C<bad>. The "first bad commit" has then to be understood as
705the "first commit where the bug is solved".
d82a90c1 706
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707C<git help bisect> has much more information on how you can tweak your
708binary searches.
9d68b7ed 709
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710=head1 SUBMITTING A PATCH VIA GITHUB
711
712GitHub is a website that makes it easy to fork and publish projects
713with Git. First you should set up a GitHub account and log in.
714
715Perl's git repository is mirrored on GitHub at this page:
716
717 http://github.com/github/perl/tree/blead
718
719Visit the page and click the "fork" button. This clones the Perl git
720repository for you and provides you with "Your Clone URL" from which
721you should clone:
722
723 % git clone git@github.com:USERNAME/perl.git perl-github
724
bdaf0bc6 725The same patch as above, using github might look like this:
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726
727 % cd perl-github
728 % git remote add upstream git://github.com/github/perl.git
729 % git pull upstream blead
730 % git checkout -b orange
731 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
dc3c3040 732 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
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733 % git push origin orange
734
735The orange branch has been pushed to GitHub, so you should now send an
736email to perl5-porters@perl.org with a description of your changes and
737the following information:
738
739 http://github.com/USERNAME/perl/tree/orange
740 git@github.com:USERNAME/perl.git branch orange
741
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742=head1 MERGING FROM A BRANCH VIA GITHUB
743
744If someone has provided a branch via GitHub and you are a committer,
5c9c28c6 745you should use the following in your perl-ssh directory:
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746
747 % git remote add dandv git://github.com/dandv/perl.git
fe442cc0 748 % git fetch dandv
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749
750Now you can see the differences between the branch and blead:
751
752 % git diff dandv/blead
753
754And you can see the commits:
755
756 % git log dandv/blead
757
758If you approve of a specific commit, you can cherry pick it:
759
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760 % git cherry-pick 3adac458cb1c1d41af47fc66e67b49c8dec2323f
761
762Or you could just merge the whole branch if you like it all:
763
764 % git merge dandv/blead
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765
766And then push back to the repository:
767
768 % git push
769
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770
771=head1 TOPIC BRANCHES AND REWRITING HISTORY
772
773Individual committers should create topic branches under
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774B<yourname>/B<some_descriptive_name>. Other committers should check
775with a topic branch's creator before making any change to it.
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776
777If you are not the creator of B<yourname>/B<some_descriptive_name>, you
778might sometimes find that the original author has edited the branch's
779history. There are lots of good reasons for this. Sometimes, an author
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780might simply be rebasing the branch onto a newer source point.
781Sometimes, an author might have found an error in an early commit which
782they wanted to fix before merging the branch to blead.
ce2a8773 783
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784Currently the master repository is configured to forbid
785non-fast-forward merges. This means that the branches within can not
786be rebased and pushed as a single step.
ce2a8773 787
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788The only way you will ever be allowed to rebase or modify the history
789of a pushed branch is to delete it and push it as a new branch under
790the same name. Please think carefully about doing this. It may be
791better to sequentially rename your branches so that it is easier for
792others working with you to cherry-pick their local changes onto the new
793version. (XXX: needs explanation).
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794
795If you want to rebase a personal topic branch, you will have to delete
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796your existing topic branch and push as a new version of it. You can do
797this via the following formula (see the explanation about C<refspec>'s
798in the git push documentation for details) after you have rebased your
799branch:
800
801 # first rebase
802 $ git checkout $user/$topic
803 $ git fetch
804 $ git rebase origin/blead
805
806 # then "delete-and-push"
807 $ git push origin :$user/$topic
808 $ git push origin $user/$topic
809
810B<NOTE:> it is forbidden at the repository level to delete any of the
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811"primary" branches. That is any branch matching
812C<m!^(blead|maint|perl)!>. Any attempt to do so will result in git
813producing an error like this:
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814
815 $ git push origin :blead
816 *** It is forbidden to delete blead/maint branches in this repository
817 error: hooks/update exited with error code 1
818 error: hook declined to update refs/heads/blead
333f8875 819 To ssh://perl5.git.perl.org/perl
2699d634 820 ! [remote rejected] blead (hook declined)
333f8875 821 error: failed to push some refs to 'ssh://perl5.git.perl.org/perl'
2699d634 822
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823As a matter of policy we do B<not> edit the history of the blead and
824maint-* branches. If a typo (or worse) sneaks into a commit to blead or
825maint-*, we'll fix it in another commit. The only types of updates
826allowed on these branches are "fast-forward's", where all history is
827preserved.
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829Annotated tags in the canonical perl.git repository will never be
830deleted or modified. Think long and hard about whether you want to push
831a local tag to perl.git before doing so. (Pushing unannotated tags is
2699d634 832not allowed.)
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9469eb4a 834=head1 COMMITTING TO MAINTENANCE VERSIONS
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836Maintenance versions should only be altered to add critical bug fixes.
837
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838To commit to a maintenance version of perl, you need to create a local
839tracking branch:
840
841 % git checkout --track -b maint-5.005 origin/maint-5.005
842
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843This creates a local branch named C<maint-5.005>, which tracks the
844remote branch C<origin/maint-5.005>. Then you can pull, commit, merge
845and push as before.
b0d36535 846
f755e97d 847You can also cherry-pick commits from blead and another branch, by
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848using the C<git cherry-pick> command. It is recommended to use the
849B<-x> option to C<git cherry-pick> in order to record the SHA1 of the
850original commit in the new commit message.
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852=head1 GRAFTS
853
854The perl history contains one mistake which was not caught in the
ac036724 855conversion: a merge was recorded in the history between blead and
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856maint-5.10 where no merge actually occurred. Due to the nature of git,
857this is now impossible to fix in the public repository. You can remove
858this mis-merge locally by adding the following line to your
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859C<.git/info/grafts> file:
860
861 296f12bbbbaa06de9be9d09d3dcf8f4528898a49 434946e0cb7a32589ed92d18008aaa1d88515930
862
863It is particularly important to have this graft line if any bisecting
864is done in the area of the "merge" in question.
865
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866
867
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868=head1 SEE ALSO
869
870The git documentation, accessible via C<git help command>.
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