This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
[perl #71676] GDBM_File support on Win32
[perl5.git] / pod / perlrepository.pod
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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
3b8a5fb0 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
572f57ba 48fetch a copy of the repository over HTTP (this is slower):
d7dd28b6 49
3b8a5fb0 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
3482f01a 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
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65If you cloned using the git protocol, which is faster than ssh, then
66you will need to modify your config in order to enable pushing. Edit
67F<.git/config> where you will see something like:
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68
69 [remote "origin"]
70 url = git://perl5.git.perl.org/perl.git
71
72change that to something like this:
73
74 [remote "origin"]
3482f01a 75 url = ssh://perl5.git.perl.org/perl.git
d7dd28b6 76
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77You can also set up your user name and e-mail address. For example
78
79 % git config user.name "Leon Brocard"
80 % git config user.email acme@astray.com
81
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82It is also possible to keep C<origin> as a git remote, and add a new
83remote for ssh access:
f6c12373 84
dc3c3040 85 % git remote add camel perl5.git.perl.org:/perl.git
f6c12373 86
6acba58e 87This allows you to update your local repository by pulling from
f755e97d 88C<origin>, which is faster and doesn't require you to authenticate, and
6acba58e 89to push your changes back with the C<camel> remote:
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90
91 % git fetch camel
92 % git push camel
93
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94The C<fetch> command just updates the C<camel> refs, as the objects
95themselves should have been fetched when pulling from C<origin>.
f6c12373 96
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97=head2 A NOTE ON CAMEL AND DROMEDARY
98
99The committers have SSH access to the two servers that serve
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100C<perl5.git.perl.org>. One is C<perl5.git.perl.org> itself (I<camel>),
101which is the 'master' repository. The second one is
102C<users.perl5.git.perl.org> (I<dromedary>), which can be used for
103general testing and development. Dromedary syncs the git tree from
104camel every few minutes, you should not push there. Both machines also
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105have a full CPAN mirror in /srv/CPAN, please use this. To share files
106with the general public, dromedary serves your ~/public_html/ as
333f8875 107C<http://users.perl5.git.perl.org/~yourlogin/>
b47aa495 108
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109These hosts have fairly strict firewalls to the outside. Outgoing, only
110rsync, ssh and git are allowed. For http and ftp, you can use
111http://webproxy:3128 as proxy. Incoming, the firewall tries to detect
112attacks and blocks IP addresses with suspicious activity. This
113sometimes (but very rarely) has false positives and you might get
114blocked. The quickest way to get unblocked is to notify the admins.
115
116These two boxes are owned, hosted, and operated by booking.com. You can
117reach the sysadmins in #p5p on irc.perl.org or via mail to
118C<perl5-porters@perl.org>
119
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120=head1 OVERVIEW OF THE REPOSITORY
121
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122Once you have changed into the repository directory, you can inspect
123it.
d7dd28b6 124
39219fd3 125After a clone the repository will contain a single local branch, which
50eca761 126will be the current branch as well, as indicated by the asterisk.
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127
128 % git branch
129 * blead
130
f755e97d 131Using the -a switch to C<branch> will also show the remote tracking
6acba58e 132branches in the repository:
39219fd3 133
d9847473 134 % git branch -a
09081495 135 * blead
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136 origin/HEAD
137 origin/blead
138 ...
139
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140The branches that begin with "origin" correspond to the "git remote"
141that you cloned from (which is named "origin"). Each branch on the
142remote will be exactly tracked by theses branches. You should NEVER do
143work on these remote tracking branches. You only ever do work in a
144local branch. Local branches can be configured to automerge (on pull)
145from a designated remote tracking branch. This is the case with the
146default branch C<blead> which will be configured to merge from the
147remote tracking branch C<origin/blead>.
39219fd3 148
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149You can see recent commits:
150
c2cf2042 151 % git log
d7dd28b6 152
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153And pull new changes from the repository, and update your local
154repository (must be clean first)
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155
156 % git pull
09081495 157
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158Assuming we are on the branch C<blead> immediately after a pull, this
159command would be more or less equivalent to:
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160
161 % git fetch
162 % git merge origin/blead
163
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164In fact if you want to update your local repository without touching
165your working directory you do:
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166
167 % git fetch
168
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169And if you want to update your remote-tracking branches for all defined
170remotes simultaneously you can do
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171
172 % git remote update
173
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174Neither of these last two commands will update your working directory,
175however both will update the remote-tracking branches in your
176repository.
39219fd3 177
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178To switch to another branch:
179
180 % git checkout origin/maint-5.8-dor
181
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182To make a local branch of a remote branch:
183
184 % git checkout -b maint-5.10 origin/maint-5.10
185
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186To switch back to blead:
187
188 % git checkout blead
c2cf2042 189
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190=head2 FINDING OUT YOUR STATUS
191
192The most common git command you will use will probably be
193
194 % git status
195
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196This command will produce as output a description of the current state
197of the repository, including modified files and unignored untracked
198files, and in addition it will show things like what files have been
199staged for the next commit, and usually some useful information about
200how to change things. For instance the following:
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201
202 $ git status
203 # On branch blead
204 # Your branch is ahead of 'origin/blead' by 1 commit.
205 #
206 # Changes to be committed:
207 # (use "git reset HEAD <file>..." to unstage)
208 #
209 # modified: pod/perlrepository.pod
210 #
211 # Changed but not updated:
212 # (use "git add <file>..." to update what will be committed)
213 #
214 # modified: pod/perlrepository.pod
215 #
216 # Untracked files:
217 # (use "git add <file>..." to include in what will be committed)
218 #
219 # deliberate.untracked
220
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221This shows that there were changes to this document staged for commit,
222and that there were further changes in the working directory not yet
223staged. It also shows that there was an untracked file in the working
224directory, and as you can see shows how to change all of this. It also
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225shows that there is one commit on the working branch C<blead> which has
226not been pushed to the C<origin> remote yet. B<NOTE>: that this output
227is also what you see as a template if you do not provide a message to
228C<git commit>.
7f6effc7 229
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230Assuming that you'd like to commit all the changes you've just made as a
231a single atomic unit, run this command:
232
233 % git commit -a
234
235(That C<-a> tells git to add every file you've changed to this commit.
236If you want to commit some, but not all of your changes, have a look
237at the documentation for C<git add>.)
238
e9360695 239Git will start up your favorite text editor, so that you can craft a
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240commit message for your change. See L</Commit message> below for more
241information about what makes a good commit message.
242
243Once you've finished writing your commit message and exited your editor,
244git will write your change to disk and tell you something like this:
7f6effc7 245
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246 Created commit daf8e63: explain git status and stuff about remotes
247 1 files changed, 83 insertions(+), 3 deletions(-)
248
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249
250If you re-run C<git status>, you should see something like this:
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251
252 % git status
253 # On branch blead
254 # Your branch is ahead of 'origin/blead' by 2 commits.
255 #
256 # Untracked files:
257 # (use "git add <file>..." to include in what will be committed)
258 #
259 # deliberate.untracked
260 nothing added to commit but untracked files present (use "git add" to track)
261
39219fd3 262
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263When in doubt, before you do anything else, check your status and read
264it carefully, many questions are answered directly by the git status
265output.
39219fd3 266
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267=head1 SUBMITTING A PATCH
268
269If you have a patch in mind for Perl, you should first get a copy of
270the repository:
271
272 % git clone git://perl5.git.perl.org/perl.git perl-git
273
274Then change into the directory:
275
276 % cd perl-git
277
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278Alternatively, if you already have a Perl repository, you should ensure
279that you're on the I<blead> branch, and your repository is up to date:
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280
281 % git checkout blead
282 % git pull
283
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284It's preferable to patch against the latest blead version, since this
285is where new development occurs for all changes other than critical bug
286fixes. Critical bug fix patches should be made against the relevant
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287maint branches, or should be submitted with a note indicating all the
288branches where the fix should be applied.
a44f43ac 289
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290Now that we have everything up to date, we need to create a temporary
291new branch for these changes and switch into it:
b1fccde5 292
a9b05323 293 % git checkout -b orange
23f8d33e 294
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295which is the short form of
296
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297 % git branch orange
298 % git checkout orange
299
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300Then make your changes. For example, if Leon Brocard changes his name
301to Orange Brocard, we should change his name in the AUTHORS file:
302
303 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
304
305You can see what files are changed:
306
307 % git status
f755e97d 308 # On branch orange
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309 # Changes to be committed:
310 # (use "git reset HEAD <file>..." to unstage)
311 #
2699d634 312 # modified: AUTHORS
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313 #
314
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315And you can see the changes:
316
317 % git diff
318 diff --git a/AUTHORS b/AUTHORS
319 index 293dd70..722c93e 100644
320 --- a/AUTHORS
321 +++ b/AUTHORS
7df2e4bc 322 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
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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>
331
332Now commit your change locally:
333
dc3c3040 334 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
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335 Created commit 6196c1d: Rename Leon Brocard to Orange Brocard
336 1 files changed, 1 insertions(+), 1 deletions(-)
337
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338You can examine your last commit with:
339
340 % git show HEAD
341
342and if you are not happy with either the description or the patch
c26da522 343itself you can fix it up by editing the files once more and then issue:
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344
345 % git commit -a --amend
346
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347Now you should create a patch file for all your local changes:
348
2af192ee 349 % git format-patch origin
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350 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
351
352You should now send an email to perl5-porters@perl.org with a
dc3c3040 353description of your changes, and include this patch file as an
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354attachment. (See the next section for how to configure and use git to
355send these emails for you.)
c2cf2042 356
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357If you want to delete your temporary branch, you may do so with:
358
359 % git checkout blead
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.
7df2e4bc 365
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366=head2 Using git to send patch emails
367
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368In your ~/git/perl repository, set the destination email to the
369perl5-porters mailing list.
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370
371 $ git config sendemail.to perl5-porters@perl.org
372
373Then you can use git directly to send your patch emails:
374
375 $ git send-email 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
376
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377You may need to set some configuration variables for your particular
378email service provider. For example, to set your global git config to
379send email via a gmail account:
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380
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
384
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385With this configuration, you will be prompted for your gmail password
386when you run 'git send-email'. You can also configure
387C<sendemail.smtppass> with your password if you don't care about having
388your password in the .gitconfig file.
2d5f1d01 389
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390=head2 A note on derived files
391
392Be aware that many files in the distribution are derivative--avoid
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393patching them, because git won't see the changes to them, and the build
394process will overwrite them. Patch the originals instead. Most
395utilities (like perldoc) are in this category, i.e. patch
396utils/perldoc.PL rather than utils/perldoc. Similarly, don't create
397patches 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
399file that may have gotten copied while building the source
400distribution, consult the C<MANIFEST>.
a44f43ac 401
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402As a special case, several files are regenerated by 'make regen' if
403your patch alters C<embed.fnc>. These are needed for compilation, but
404are included in the distribution so that you can build perl without
405needing another perl to generate the files. You must test with these
406regenerated files, but it is preferred that you instead note that
407'make regen is needed' in both the email and the commit message, and
408submit your patch without them. If you're submitting a series of
409patches, it might be best to submit the regenerated changes
410immediately after the source-changes that caused them, so as to have
411as little effect as possible on the bisectability of your patchset.
412
6e2cec71 413=for XXX
a44f43ac 414
6e2cec71 415What should we recommend about binary files now? Do we need anything?
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416
417=head2 Getting your patch accepted
418
bdaf0bc6 419If you are submitting a code patch there are several things that
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420you need to do.
421
422=over 4
423
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424=item Commit message
425
426As you craft each patch you intend to submit to the Perl core, it's
427important to write a good commit message.
428
429Your commit message should start with a description of the problem that
430the patch corrects or new functionality that the patch adds.
431
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432As a general rule of thumb, your commit message should let a programmer
433with a reasonable familiarity with the Perl core quickly understand what
434you were trying to do, how you were trying to do it and why the change
435matters to Perl.
436
437=over 4
438
439=item What
440
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441Your commit message should describe what part of the Perl core you're
442changing and what you expect your patch to do.
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443
444=item Why
445
446Perhaps most importantly, your commit message should describe why the
447change you are making is important. When someone looks at your change
448in six months or six years, your intent should be clear. If you're
449deprecating a feature with the intent of later simplifying another bit
450of code, say so. If you're fixing a performance problem or adding a new
451feature to support some other bit of the core, mention that.
452
453=item How
454
455While it's not necessary for documentation changes, new tests or
456trivial patches, it's often worth explaining how your change works.
457Even if it's clear to you today, it may not be clear to a porter next
458month or next year.
459
460=back
461
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462=item Comments, Comments, Comments
463
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464Be sure to adequately comment your code. While commenting every line
465is unnecessary, anything that takes advantage of side effects of
a44f43ac 466operators, that creates changes that will be felt outside of the
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467function being patched, or that others may find confusing should be
468documented. If you are going to err, it is better to err on the side
469of adding too many comments than too few.
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470
471=item Style
472
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473In general, please follow the particular style of the code you are
474patching.
a44f43ac 475
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476In particular, follow these general guidelines for patching Perl
477sources:
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478
479 8-wide tabs (no exceptions!)
480 4-wide indents for code, 2-wide indents for nested CPP #defines
481 try hard not to exceed 79-columns
482 ANSI C prototypes
483 uncuddled elses and "K&R" style for indenting control constructs
484 no C++ style (//) comments
485 mark places that need to be revisited with XXX (and revisit often!)
486 opening brace lines up with "if" when conditional spans multiple
487 lines; should be at end-of-line otherwise
488 in function definitions, name starts in column 0 (return value is on
489 previous line)
490 single space after keywords that are followed by parens, no space
491 between function name and following paren
492 avoid assignments in conditionals, but if they're unavoidable, use
493 extra paren, e.g. "if (a && (b = c)) ..."
494 "return foo;" rather than "return(foo);"
495 "if (!foo) ..." rather than "if (foo == FALSE) ..." etc.
496
497=item Testsuite
498
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499If your patch changes code (rather than just changing documentation) you
500should also include one or more test cases which illustrate the bug you're
501fixing or validate the new functionality you're adding. In general,
502you should update an existing test file rather than create a new one.
503
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504Your testsuite additions should generally follow these guidelines
505(courtesy of Gurusamy Sarathy <gsar@activestate.com>):
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506
507 Know what you're testing. Read the docs, and the source.
508 Tend to fail, not succeed.
509 Interpret results strictly.
510 Use unrelated features (this will flush out bizarre interactions).
511 Use non-standard idioms (otherwise you are not testing TIMTOWTDI).
512 Avoid using hardcoded test numbers whenever possible (the
513 EXPECTED/GOT found in t/op/tie.t is much more maintainable,
514 and gives better failure reports).
515 Give meaningful error messages when a test fails.
516 Avoid using qx// and system() unless you are testing for them. If you
517 do use them, make sure that you cover _all_ perl platforms.
518 Unlink any temporary files you create.
519 Promote unforeseen warnings to errors with $SIG{__WARN__}.
520 Be sure to use the libraries and modules shipped with the version
521 being tested, not those that were already installed.
522 Add comments to the code explaining what you are testing for.
523 Make updating the '1..42' string unnecessary. Or make sure that
524 you update it.
525 Test _all_ behaviors of a given operator, library, or function:
526 - All optional arguments
527 - Return values in various contexts (boolean, scalar, list, lvalue)
528 - Use both global and lexical variables
529 - Don't forget the exceptional, pathological cases.
530
531=back
532
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533=head1 ACCEPTING A PATCH
534
535If you have received a patch file generated using the above section,
536you should try out the patch.
537
538First we need to create a temporary new branch for these changes and
539switch into it:
540
a9b05323 541 % git checkout -b experimental
7df2e4bc 542
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543Patches that were formatted by C<git format-patch> are applied with
544C<git am>:
7df2e4bc 545
2af192ee 546 % git am 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
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547 Applying Rename Leon Brocard to Orange Brocard
548
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549If just a raw diff is provided, it is also possible use this two-step
550process:
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551
552 % git apply bugfix.diff
dc3c3040 553 % git commit -a -m "Some fixing" --author="That Guy <that.guy@internets.com>"
09645c26 554
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555Now we can inspect the change:
556
dc3c3040 557 % git show HEAD
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558 commit b1b3dab48344cff6de4087efca3dbd63548ab5e2
559 Author: Leon Brocard <acme@astray.com>
560 Date: Fri Dec 19 17:02:59 2008 +0000
561
562 Rename Leon Brocard to Orange Brocard
7df2e4bc 563
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564 diff --git a/AUTHORS b/AUTHORS
565 index 293dd70..722c93e 100644
566 --- a/AUTHORS
567 +++ b/AUTHORS
568 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
569 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
570 Leif Huhn <leif@hale.dkstat.com>
571 Len Johnson <lenjay@ibm.net>
572 -Leon Brocard <acme@astray.com>
573 +Orange Brocard <acme@astray.com>
574 Les Peters <lpeters@aol.net>
575 Lesley Binks <lesley.binks@gmail.com>
576 Lincoln D. Stein <lstein@cshl.org>
577
578If you are a committer to Perl and you think the patch is good, you can
75fb7651 579then merge it into blead then push it out to the main repository:
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580
581 % git checkout blead
d9847473 582 % git merge experimental
75fb7651 583 % git push
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584
585If you want to delete your temporary branch, you may do so with:
586
587 % git checkout blead
588 % git branch -d experimental
589 error: The branch 'experimental' is not an ancestor of your current HEAD.
590 If you are sure you want to delete it, run 'git branch -D experimental'.
591 % git branch -D experimental
592 Deleted branch experimental.
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593
594=head1 CLEANING A WORKING DIRECTORY
595
6acba58e 596The command C<git clean> can with varying arguments be used as a
dc3c3040 597replacement for C<make clean>.
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598
599To reset your working directory to a pristine condition you can do:
600
601 git clean -dxf
602
603However, be aware this will delete ALL untracked content. You can use
604
605 git clean -Xf
606
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607to remove all ignored untracked files, such as build and test
608byproduct, but leave any manually created files alone.
b0d36535 609
0549aefb 610If you only want to cancel some uncommitted edits, you can use C<git
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611checkout> and give it a list of files to be reverted, or C<git checkout
612-f> to revert them all.
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613
614If you want to cancel one or several commits, you can use C<git reset>.
615
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616=head1 BISECTING
617
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618C<git> provides a built-in way to determine, with a binary search in
619the history, which commit should be blamed for introducing a given bug.
d82a90c1 620
6acba58e 621Suppose that we have a script F<~/testcase.pl> that exits with C<0>
bdaf0bc6 622when some behaviour is correct, and with C<1> when it's faulty. You need
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623an helper script that automates building C<perl> and running the
624testcase:
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625
626 % cat ~/run
627 #!/bin/sh
628 git clean -dxf
629 # If you can use ccache, add -Dcc=ccache\ gcc -Dld=gcc to the Configure line
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630 # if Encode is not needed for the test, you can speed up the bisect by
631 # excluding it from the runs with -Dnoextensions=Encode
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632 sh Configure -des -Dusedevel -Doptimize="-g"
633 test -f config.sh || exit 125
634 # Correct makefile for newer GNU gcc
635 perl -ni -we 'print unless /<(?:built-in|command)/' makefile x2p/makefile
636 # if you just need miniperl, replace test_prep with miniperl
637 make -j4 test_prep
68814ba4 638 [ -x ./perl ] || exit 125
d82a90c1 639 ./perl -Ilib ~/testcase.pl
c0d1ef72 640 ret=$?
7930c68b 641 [ $ret -gt 127 ] && ret=127
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642 git clean -dxf
643 exit $ret
d82a90c1 644
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645This script may return C<125> to indicate that the corresponding commit
646should be skipped. Otherwise, it returns the status of
647F<~/testcase.pl>.
d82a90c1 648
bdaf0bc6 649You first enter in bisect mode with:
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650
651 % git bisect start
652
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653For example, if the bug is present on C<HEAD> but wasn't in 5.10.0,
654C<git> will learn about this when you enter:
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655
656 % git bisect bad
657 % git bisect good perl-5.10.0
658 Bisecting: 853 revisions left to test after this
659
6acba58e 660This results in checking out the median commit between C<HEAD> and
bdaf0bc6 661C<perl-5.10.0>. You can then run the bisecting process with:
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662
663 % git bisect run ~/run
664
665When the first bad commit is isolated, C<git bisect> will tell you so:
666
667 ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 is first bad commit
668 commit ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5
669 Author: Dave Mitchell <davem@fdisolutions.com>
670 Date: Sat Feb 9 14:56:23 2008 +0000
671
9469eb4a 672 [perl #49472] Attributes + Unknown Error
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673 ...
674
675 bisect run success
676
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677You can peek into the bisecting process with C<git bisect log> and
678C<git bisect visualize>. C<git bisect reset> will get you out of bisect
679mode.
d82a90c1 680
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681Please note that the first C<good> state must be an ancestor of the
682first C<bad> state. If you want to search for the commit that I<solved>
683some bug, you have to negate your test case (i.e. exit with C<1> if OK
684and C<0> if not) and still mark the lower bound as C<good> and the
685upper as C<bad>. The "first bad commit" has then to be understood as
686the "first commit where the bug is solved".
d82a90c1 687
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688C<git help bisect> has much more information on how you can tweak your
689binary searches.
9d68b7ed 690
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691=head1 SUBMITTING A PATCH VIA GITHUB
692
693GitHub is a website that makes it easy to fork and publish projects
694with Git. First you should set up a GitHub account and log in.
695
696Perl's git repository is mirrored on GitHub at this page:
697
698 http://github.com/github/perl/tree/blead
699
700Visit the page and click the "fork" button. This clones the Perl git
701repository for you and provides you with "Your Clone URL" from which
702you should clone:
703
704 % git clone git@github.com:USERNAME/perl.git perl-github
705
bdaf0bc6 706The same patch as above, using github might look like this:
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707
708 % cd perl-github
709 % git remote add upstream git://github.com/github/perl.git
710 % git pull upstream blead
711 % git checkout -b orange
712 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
dc3c3040 713 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
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714 % git push origin orange
715
716The orange branch has been pushed to GitHub, so you should now send an
717email to perl5-porters@perl.org with a description of your changes and
718the following information:
719
720 http://github.com/USERNAME/perl/tree/orange
721 git@github.com:USERNAME/perl.git branch orange
722
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723=head1 MERGING FROM A BRANCH VIA GITHUB
724
725If someone has provided a branch via GitHub and you are a committer,
5c9c28c6 726you should use the following in your perl-ssh directory:
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727
728 % git remote add dandv git://github.com/dandv/perl.git
729 % git fetch
730
731Now you can see the differences between the branch and blead:
732
733 % git diff dandv/blead
734
735And you can see the commits:
736
737 % git log dandv/blead
738
739If you approve of a specific commit, you can cherry pick it:
740
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741 % git cherry-pick 3adac458cb1c1d41af47fc66e67b49c8dec2323f
742
743Or you could just merge the whole branch if you like it all:
744
745 % git merge dandv/blead
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746
747And then push back to the repository:
748
749 % git push
750
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751
752=head1 TOPIC BRANCHES AND REWRITING HISTORY
753
754Individual committers should create topic branches under
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755B<yourname>/B<some_descriptive_name>. Other committers should check
756with a topic branch's creator before making any change to it.
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757
758If you are not the creator of B<yourname>/B<some_descriptive_name>, you
759might sometimes find that the original author has edited the branch's
760history. There are lots of good reasons for this. Sometimes, an author
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761might simply be rebasing the branch onto a newer source point.
762Sometimes, an author might have found an error in an early commit which
763they wanted to fix before merging the branch to blead.
ce2a8773 764
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765Currently the master repository is configured to forbid
766non-fast-forward merges. This means that the branches within can not
767be rebased and pushed as a single step.
ce2a8773 768
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769The only way you will ever be allowed to rebase or modify the history
770of a pushed branch is to delete it and push it as a new branch under
771the same name. Please think carefully about doing this. It may be
772better to sequentially rename your branches so that it is easier for
773others working with you to cherry-pick their local changes onto the new
774version. (XXX: needs explanation).
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775
776If you want to rebase a personal topic branch, you will have to delete
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777your existing topic branch and push as a new version of it. You can do
778this via the following formula (see the explanation about C<refspec>'s
779in the git push documentation for details) after you have rebased your
780branch:
781
782 # first rebase
783 $ git checkout $user/$topic
784 $ git fetch
785 $ git rebase origin/blead
786
787 # then "delete-and-push"
788 $ git push origin :$user/$topic
789 $ git push origin $user/$topic
790
791B<NOTE:> it is forbidden at the repository level to delete any of the
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792"primary" branches. That is any branch matching
793C<m!^(blead|maint|perl)!>. Any attempt to do so will result in git
794producing an error like this:
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795
796 $ git push origin :blead
797 *** It is forbidden to delete blead/maint branches in this repository
798 error: hooks/update exited with error code 1
799 error: hook declined to update refs/heads/blead
333f8875 800 To ssh://perl5.git.perl.org/perl
2699d634 801 ! [remote rejected] blead (hook declined)
333f8875 802 error: failed to push some refs to 'ssh://perl5.git.perl.org/perl'
2699d634 803
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804As a matter of policy we do B<not> edit the history of the blead and
805maint-* branches. If a typo (or worse) sneaks into a commit to blead or
806maint-*, we'll fix it in another commit. The only types of updates
807allowed on these branches are "fast-forward's", where all history is
808preserved.
2699d634 809
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810Annotated tags in the canonical perl.git repository will never be
811deleted or modified. Think long and hard about whether you want to push
812a local tag to perl.git before doing so. (Pushing unannotated tags is
2699d634 813not allowed.)
ce2a8773 814
9469eb4a 815=head1 COMMITTING TO MAINTENANCE VERSIONS
9d68b7ed 816
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817Maintenance versions should only be altered to add critical bug fixes.
818
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819To commit to a maintenance version of perl, you need to create a local
820tracking branch:
821
822 % git checkout --track -b maint-5.005 origin/maint-5.005
823
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824This creates a local branch named C<maint-5.005>, which tracks the
825remote branch C<origin/maint-5.005>. Then you can pull, commit, merge
826and push as before.
b0d36535 827
f755e97d 828You can also cherry-pick commits from blead and another branch, by
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829using the C<git cherry-pick> command. It is recommended to use the
830B<-x> option to C<git cherry-pick> in order to record the SHA1 of the
831original commit in the new commit message.
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833=head1 GRAFTS
834
835The perl history contains one mistake which was not caught in the
ac036724 836conversion: a merge was recorded in the history between blead and
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837maint-5.10 where no merge actually occurred. Due to the nature of git,
838this is now impossible to fix in the public repository. You can remove
839this mis-merge locally by adding the following line to your
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840C<.git/info/grafts> file:
841
842 296f12bbbbaa06de9be9d09d3dcf8f4528898a49 434946e0cb7a32589ed92d18008aaa1d88515930
843
844It is particularly important to have this graft line if any bisecting
845is done in the area of the "merge" in question.
846
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847
848
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849=head1 SEE ALSO
850
851The git documentation, accessible via C<git help command>.
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