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perlgit.pod: Remove one mention of p5p
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2
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3=for comment
4Consistent formatting of this file is achieved with:
04c692a8 5 perl ./Porting/podtidy pod/perlgit.pod
0549aefb 6
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7=head1 NAME
8
04c692a8 9perlgit - Detailed information about git and the Perl repository
d7dd28b6 10
04c692a8 11=head1 DESCRIPTION
d7dd28b6 12
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13This document provides details on using git to develop Perl. If you are
14just interested in working on a quick patch, see L<perlhack> first.
15This document is intended for people who are regular contributors to
16Perl, including those with write access to the git repository.
184487f0 17
04c692a8 18=head1 CLONING THE REPOSITORY
f6c12373 19
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20All of Perl's source code is kept centrally in a Git repository at
21I<perl5.git.perl.org>.
f6c12373 22
04c692a8 23You can make a read-only clone of the repository by running:
f6c12373 24
04c692a8 25 % git clone git://perl5.git.perl.org/perl.git perl
f6c12373 26
04c692a8 27This uses the git protocol (port 9418).
f6c12373 28
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29If you cannot use the git protocol for firewall reasons, you can also
30clone via http, though this is much slower:
3482f01a 31
04c692a8 32 % git clone http://perl5.git.perl.org/perl.git perl
b47aa495 33
04c692a8 34=head1 WORKING WITH THE REPOSITORY
d7dd28b6 35
6acba58e 36Once you have changed into the repository directory, you can inspect
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37it. After a clone the repository will contain a single local branch,
38which will be the current branch as well, as indicated by the asterisk.
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39
40 % git branch
41 * blead
42
f755e97d 43Using the -a switch to C<branch> will also show the remote tracking
6acba58e 44branches in the repository:
39219fd3 45
d9847473 46 % git branch -a
09081495 47 * blead
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48 origin/HEAD
49 origin/blead
50 ...
51
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52The branches that begin with "origin" correspond to the "git remote"
53that you cloned from (which is named "origin"). Each branch on the
c9d1da35 54remote will be exactly tracked by these branches. You should NEVER do
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55work on these remote tracking branches. You only ever do work in a
56local branch. Local branches can be configured to automerge (on pull)
57from a designated remote tracking branch. This is the case with the
58default branch C<blead> which will be configured to merge from the
59remote tracking branch C<origin/blead>.
39219fd3 60
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61You can see recent commits:
62
c2cf2042 63 % git log
d7dd28b6 64
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65And pull new changes from the repository, and update your local
66repository (must be clean first)
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67
68 % git pull
09081495 69
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70Assuming we are on the branch C<blead> immediately after a pull, this
71command would be more or less equivalent to:
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72
73 % git fetch
74 % git merge origin/blead
75
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76In fact if you want to update your local repository without touching
77your working directory you do:
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78
79 % git fetch
80
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81And if you want to update your remote-tracking branches for all defined
82remotes simultaneously you can do
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83
84 % git remote update
85
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86Neither of these last two commands will update your working directory,
87however both will update the remote-tracking branches in your
88repository.
39219fd3 89
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90To make a local branch of a remote branch:
91
92 % git checkout -b maint-5.10 origin/maint-5.10
93
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94To switch back to blead:
95
96 % git checkout blead
c2cf2042 97
ba336be1 98=head2 Finding out your status
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99
100The most common git command you will use will probably be
101
102 % git status
103
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104This command will produce as output a description of the current state
105of the repository, including modified files and unignored untracked
106files, and in addition it will show things like what files have been
107staged for the next commit, and usually some useful information about
108how to change things. For instance the following:
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109
110 $ git status
111 # On branch blead
112 # Your branch is ahead of 'origin/blead' by 1 commit.
113 #
114 # Changes to be committed:
115 # (use "git reset HEAD <file>..." to unstage)
116 #
04c692a8 117 # modified: pod/perlgit.pod
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118 #
119 # Changed but not updated:
120 # (use "git add <file>..." to update what will be committed)
121 #
04c692a8 122 # modified: pod/perlgit.pod
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123 #
124 # Untracked files:
125 # (use "git add <file>..." to include in what will be committed)
126 #
127 # deliberate.untracked
128
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129This shows that there were changes to this document staged for commit,
130and that there were further changes in the working directory not yet
131staged. It also shows that there was an untracked file in the working
132directory, and as you can see shows how to change all of this. It also
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133shows that there is one commit on the working branch C<blead> which has
134not been pushed to the C<origin> remote yet. B<NOTE>: that this output
135is also what you see as a template if you do not provide a message to
136C<git commit>.
7f6effc7 137
04c692a8 138=head2 Patch workflow
7f6effc7 139
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140First, please read L<perlhack> for details on hacking the Perl core.
141That document covers many details on how to create a good patch.
7f6effc7 142
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143If you already have a Perl repository, you should ensure that you're on
144the I<blead> branch, and your repository is up to date:
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145
146 % git checkout blead
147 % git pull
148
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149It's preferable to patch against the latest blead version, since this
150is where new development occurs for all changes other than critical bug
04c692a8 151fixes. Critical bug fix patches should be made against the relevant
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152maint branches, or should be submitted with a note indicating all the
153branches where the fix should be applied.
a44f43ac 154
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155Now that we have everything up to date, we need to create a temporary
156new branch for these changes and switch into it:
b1fccde5 157
a9b05323 158 % git checkout -b orange
23f8d33e 159
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160which is the short form of
161
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162 % git branch orange
163 % git checkout orange
164
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165Creating a topic branch makes it easier for the maintainers to rebase
166or merge back into the master blead for a more linear history. If you
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167don't work on a topic branch the maintainer has to manually cherry pick
168your changes onto blead before they can be applied.
0c24b290 169
77db6475 170That'll get you scolded on perl5-porters, so don't do that. Be Awesome.
0c24b290 171
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172Then make your changes. For example, if Leon Brocard changes his name
173to Orange Brocard, we should change his name in the AUTHORS file:
174
175 % perl -pi -e 's{Leon Brocard}{Orange Brocard}' AUTHORS
176
177You can see what files are changed:
178
179 % git status
f755e97d 180 # On branch orange
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181 # Changes to be committed:
182 # (use "git reset HEAD <file>..." to unstage)
183 #
2699d634 184 # modified: AUTHORS
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185 #
186
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187And you can see the changes:
188
189 % git diff
190 diff --git a/AUTHORS b/AUTHORS
191 index 293dd70..722c93e 100644
192 --- a/AUTHORS
193 +++ b/AUTHORS
7df2e4bc 194 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
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195 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
196 Leif Huhn <leif@hale.dkstat.com>
197 Len Johnson <lenjay@ibm.net>
198 -Leon Brocard <acme@astray.com>
199 +Orange Brocard <acme@astray.com>
200 Les Peters <lpeters@aol.net>
201 Lesley Binks <lesley.binks@gmail.com>
202 Lincoln D. Stein <lstein@cshl.org>
203
04c692a8 204Now commit your change locally:
77471e41 205
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206 % git commit -a -m 'Rename Leon Brocard to Orange Brocard'
207 Created commit 6196c1d: Rename Leon Brocard to Orange Brocard
208 1 files changed, 1 insertions(+), 1 deletions(-)
77471e41 209
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210The C<-a> option is used to include all files that git tracks that you
211have changed. If at this time, you only want to commit some of the
212files you have worked on, you can omit the C<-a> and use the command
213C<S<git add I<FILE ...>>> before doing the commit. C<S<git add
214--interactive>> allows you to even just commit portions of files
215instead of all the changes in them.
77471e41 216
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217The C<-m> option is used to specify the commit message. If you omit it,
218git will open a text editor for you to compose the message
219interactively. This is useful when the changes are more complex than
220the sample given here, and, depending on the editor, to know that the
221first line of the commit message doesn't exceed the 50 character legal
222maximum.
77471e41 223
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224Once you've finished writing your commit message and exited your
225editor, git will write your change to disk and tell you something like
226this:
77471e41 227
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228 Created commit daf8e63: explain git status and stuff about remotes
229 1 files changed, 83 insertions(+), 3 deletions(-)
c2cf2042 230
04c692a8 231If you re-run C<git status>, you should see something like this:
c2cf2042 232
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233 % git status
234 # On branch blead
235 # Your branch is ahead of 'origin/blead' by 2 commits.
236 #
237 # Untracked files:
238 # (use "git add <file>..." to include in what will be committed)
239 #
240 # deliberate.untracked
241 nothing added to commit but untracked files present (use "git add" to track)
2be70973 242
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243When in doubt, before you do anything else, check your status and read
244it carefully, many questions are answered directly by the git status
245output.
2be70973 246
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247You can examine your last commit with:
248
249 % git show HEAD
250
251and if you are not happy with either the description or the patch
c26da522 252itself you can fix it up by editing the files once more and then issue:
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253
254 % git commit -a --amend
255
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256Now you should create a patch file for all your local changes:
257
f15b1f22 258 % git format-patch -M origin..
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259 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
260
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261Or for a lot of changes, e.g. from a topic branch:
262
263 % git format-patch --stdout -M origin.. > topic-branch-changes.patch
264
e001c712 265You should now send an email to
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266L<perlbug@perl.org|mailto:perlbug@perl.org> with a description of your
267changes, and include this patch file as an attachment. In addition to
77db6475 268being tracked by RT, mail to perlbug will automatically be forwarded to
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269perl5-porters (with manual moderation, so please be patient). You
270should only send patches to
271L<perl5-porters@perl.org|mailto:perl5-porters@perl.org> directly if the
272patch is not ready to be applied, but intended for discussion.
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273
274See the next section for how to configure and use git to send these
275emails for you.
c2cf2042 276
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277If you want to delete your temporary branch, you may do so with:
278
279 % git checkout blead
280 % git branch -d orange
281 error: The branch 'orange' is not an ancestor of your current HEAD.
282 If you are sure you want to delete it, run 'git branch -D orange'.
283 % git branch -D orange
284 Deleted branch orange.
7df2e4bc 285
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286=head2 Committing your changes
287
6a6d7b97 288Assuming that you'd like to commit all the changes you've made as a
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289single atomic unit, run this command:
290
291 % git commit -a
292
293(That C<-a> tells git to add every file you've changed to this commit.
294New files aren't automatically added to your commit when you use
295C<commit -a> If you want to add files or to commit some, but not all of
296your changes, have a look at the documentation for C<git add>.)
297
298Git will start up your favorite text editor, so that you can craft a
299commit message for your change. See L<perlhack/Commit message> for more
300information about what makes a good commit message.
301
302Once you've finished writing your commit message and exited your
303editor, git will write your change to disk and tell you something like
304this:
305
306 Created commit daf8e63: explain git status and stuff about remotes
307 1 files changed, 83 insertions(+), 3 deletions(-)
308
309If you re-run C<git status>, you should see something like this:
310
311 % git status
312 # On branch blead
313 # Your branch is ahead of 'origin/blead' by 2 commits.
314 #
315 # Untracked files:
316 # (use "git add <file>..." to include in what will be committed)
317 #
318 # deliberate.untracked
319 nothing added to commit but untracked files present (use "git add" to track)
320
321When in doubt, before you do anything else, check your status and read
322it carefully, many questions are answered directly by the git status
323output.
324
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325=head2 Sending patch emails
326
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327After you've generated your patch you should sent it
328to perlbug@perl.org (as discussed L<in the previous
329section|/"Patch workflow"> with a normal mail client as an
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330attachment, along with a description of the patch.
331
332You B<must not> use git-send-email(1) to send patches generated with
333git-format-patch(1). The RT ticketing system living behind
334perlbug@perl.org does not respect the inline contents of E-Mails,
335sending an inline patch to RT guarantees that your patch will be
336destroyed.
337
338Someone may download your patch from RT, which will result in the
339subject (the first line of the commit message) being omitted. See RT
340#74192 and commit a4583001 for an example. Alternatively someone may
341apply your patch from RT after it arrived in their mailbox, by which
342time RT will have modified the inline content of the message. See RT
343#74532 and commit f9bcfeac for a bad example of this failure mode.
2d5f1d01 344
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345=head2 A note on derived files
346
347Be aware that many files in the distribution are derivative--avoid
0549aefb 348patching them, because git won't see the changes to them, and the build
04c692a8 349process will overwrite them. Patch the originals instead. Most
0549aefb 350utilities (like perldoc) are in this category, i.e. patch
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351F<utils/perldoc.PL> rather than F<utils/perldoc>. Similarly, don't
352create patches for files under $src_root/ext from their copies found in
04c692a8 353$install_root/lib. If you are unsure about the proper location of a
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354file that may have gotten copied while building the source
355distribution, consult the C<MANIFEST>.
a44f43ac 356
04c692a8 357=head2 Cleaning a working directory
b0d36535 358
6acba58e 359The command C<git clean> can with varying arguments be used as a
dc3c3040 360replacement for C<make clean>.
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361
362To reset your working directory to a pristine condition you can do:
363
e0b2b458 364 % git clean -dxf
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365
366However, be aware this will delete ALL untracked content. You can use
367
e0b2b458 368 % git clean -Xf
b0d36535 369
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370to remove all ignored untracked files, such as build and test
371byproduct, but leave any manually created files alone.
b0d36535 372
0549aefb 373If you only want to cancel some uncommitted edits, you can use C<git
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374checkout> and give it a list of files to be reverted, or C<git checkout
375-f> to revert them all.
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376
377If you want to cancel one or several commits, you can use C<git reset>.
378
04c692a8 379=head2 Bisecting
d82a90c1 380
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381C<git> provides a built-in way to determine which commit should be blamed
382for introducing a given bug. C<git bisect> performs a binary search of
383history to locate the first failing commit. It is fast, powerful and
384flexible, but requires some setup and to automate the process an auxiliary
385shell script is needed.
386
387The core provides a wrapper program, F<Porting/bisect.pl>, which attempts to
388simplify as much as possible, making bisecting as simple as running a Perl
389one-liner. For example, if you want to know when this became an error:
390
391 perl -e 'my $a := 2'
392
393you simply run this:
394
395 .../Porting/bisect.pl -e 'my $a := 2;'
396
397Using C<bisect.pl>, with one command (and no other files) it's easy to find
398out
399
400=over 4
401
402=item *
403
404Which commit caused this example code to break?
405
406=item *
407
408Which commit caused this example code to start working?
409
410=item *
411
412Which commit added the first file to match this regex?
413
414=item *
415
416Which commit removed the last file to match this regex?
417
418=back
419
420usually without needing to know which versions of perl to use as start and
421end revisions, as F<bisect.pl> automatically searches to find the earliest
422stable version for which the test case passes. Run
423C<Porting/bisect.pl --help> for the full documentation, including how to
424set the C<Configure> and build time options.
425
426If you require more flexibility than F<Porting/bisect.pl> has to offer, you'll
427need to run C<git bisect> yourself. It's most useful to use C<git bisect run>
428to automate the building and testing of perl revisions. For this you'll need
429a shell script for C<git> to call to test a particular revision. An example
430script is F<Porting/bisect-example.sh>, which you should copy B<outside> of
431the repository, as the bisect process will reset the state to a clean checkout
432as it runs. The instructions below assume that you copied it as F<~/run> and
433then edited it as appropriate.
d82a90c1 434
bdaf0bc6 435You first enter in bisect mode with:
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436
437 % git bisect start
438
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439For example, if the bug is present on C<HEAD> but wasn't in 5.10.0,
440C<git> will learn about this when you enter:
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441
442 % git bisect bad
443 % git bisect good perl-5.10.0
444 Bisecting: 853 revisions left to test after this
445
6acba58e 446This results in checking out the median commit between C<HEAD> and
bdaf0bc6 447C<perl-5.10.0>. You can then run the bisecting process with:
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448
449 % git bisect run ~/run
450
451When the first bad commit is isolated, C<git bisect> will tell you so:
452
453 ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5 is first bad commit
454 commit ca4cfd28534303b82a216cfe83a1c80cbc3b9dc5
455 Author: Dave Mitchell <davem@fdisolutions.com>
456 Date: Sat Feb 9 14:56:23 2008 +0000
457
9469eb4a 458 [perl #49472] Attributes + Unknown Error
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459 ...
460
461 bisect run success
462
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463You can peek into the bisecting process with C<git bisect log> and
464C<git bisect visualize>. C<git bisect reset> will get you out of bisect
465mode.
d82a90c1 466
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467Please note that the first C<good> state must be an ancestor of the
468first C<bad> state. If you want to search for the commit that I<solved>
469some bug, you have to negate your test case (i.e. exit with C<1> if OK
470and C<0> if not) and still mark the lower bound as C<good> and the
471upper as C<bad>. The "first bad commit" has then to be understood as
472the "first commit where the bug is solved".
d82a90c1 473
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474C<git help bisect> has much more information on how you can tweak your
475binary searches.
feb5e972 476
99cd8e46 477=head2 Topic branches and rewriting history
9d68b7ed 478
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479Individual committers should create topic branches under
480B<yourname>/B<some_descriptive_name>. Other committers should check
481with a topic branch's creator before making any change to it.
03050721 482
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483The simplest way to create a remote topic branch that works on all
484versions of git is to push the current head as a new branch on the
485remote, then check it out locally:
03050721 486
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487 $ branch="$yourname/$some_descriptive_name"
488 $ git push origin HEAD:$branch
489 $ git checkout -b $branch origin/$branch
03050721 490
04c692a8 491Users of git 1.7 or newer can do it in a more obvious manner:
03050721 492
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493 $ branch="$yourname/$some_descriptive_name"
494 $ git checkout -b $branch
495 $ git push origin -u $branch
03050721 496
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497If you are not the creator of B<yourname>/B<some_descriptive_name>, you
498might sometimes find that the original author has edited the branch's
499history. There are lots of good reasons for this. Sometimes, an author
500might simply be rebasing the branch onto a newer source point.
501Sometimes, an author might have found an error in an early commit which
502they wanted to fix before merging the branch to blead.
c26da522 503
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504Currently the master repository is configured to forbid
505non-fast-forward merges. This means that the branches within can not be
506rebased and pushed as a single step.
c26da522 507
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508The only way you will ever be allowed to rebase or modify the history
509of a pushed branch is to delete it and push it as a new branch under
510the same name. Please think carefully about doing this. It may be
511better to sequentially rename your branches so that it is easier for
512others working with you to cherry-pick their local changes onto the new
513version. (XXX: needs explanation).
c26da522 514
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515If you want to rebase a personal topic branch, you will have to delete
516your existing topic branch and push as a new version of it. You can do
517this via the following formula (see the explanation about C<refspec>'s
518in the git push documentation for details) after you have rebased your
519branch:
c26da522 520
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521 # first rebase
522 $ git checkout $user/$topic
523 $ git fetch
524 $ git rebase origin/blead
c26da522 525
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526 # then "delete-and-push"
527 $ git push origin :$user/$topic
528 $ git push origin $user/$topic
c26da522 529
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530B<NOTE:> it is forbidden at the repository level to delete any of the
531"primary" branches. That is any branch matching
532C<m!^(blead|maint|perl)!>. Any attempt to do so will result in git
533producing an error like this:
c26da522 534
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535 $ git push origin :blead
536 *** It is forbidden to delete blead/maint branches in this repository
537 error: hooks/update exited with error code 1
538 error: hook declined to update refs/heads/blead
539 To ssh://perl5.git.perl.org/perl
540 ! [remote rejected] blead (hook declined)
541 error: failed to push some refs to 'ssh://perl5.git.perl.org/perl'
c26da522 542
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543As a matter of policy we do B<not> edit the history of the blead and
544maint-* branches. If a typo (or worse) sneaks into a commit to blead or
545maint-*, we'll fix it in another commit. The only types of updates
546allowed on these branches are "fast-forward's", where all history is
547preserved.
2bab0636 548
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549Annotated tags in the canonical perl.git repository will never be
550deleted or modified. Think long and hard about whether you want to push
551a local tag to perl.git before doing so. (Pushing unannotated tags is
552not allowed.)
2bab0636 553
feb5e972 554=head2 Grafts
c26da522 555
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556The perl history contains one mistake which was not caught in the
557conversion: a merge was recorded in the history between blead and
558maint-5.10 where no merge actually occurred. Due to the nature of git,
559this is now impossible to fix in the public repository. You can remove
560this mis-merge locally by adding the following line to your
561C<.git/info/grafts> file:
c26da522 562
04c692a8 563 296f12bbbbaa06de9be9d09d3dcf8f4528898a49 434946e0cb7a32589ed92d18008aaa1d88515930
c26da522 564
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565It is particularly important to have this graft line if any bisecting
566is done in the area of the "merge" in question.
ce2a8773 567
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568=head1 WRITE ACCESS TO THE GIT REPOSITORY
569
570Once you have write access, you will need to modify the URL for the
571origin remote to enable pushing. Edit F<.git/config> with the
572git-config(1) command:
573
574 % git config remote.origin.url ssh://perl5.git.perl.org/perl.git
575
576You can also set up your user name and e-mail address. Most people do
577this once globally in their F<~/.gitconfig> by doing something like:
578
579 % git config --global user.name "Ævar Arnfjörð Bjarmason"
580 % git config --global user.email avarab@gmail.com
581
877637fd 582However, if you'd like to override that just for perl,
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583execute something like the following in F<perl>:
584
585 % git config user.email avar@cpan.org
586
587It is also possible to keep C<origin> as a git remote, and add a new
588remote for ssh access:
589
590 % git remote add camel perl5.git.perl.org:/perl.git
591
592This allows you to update your local repository by pulling from
593C<origin>, which is faster and doesn't require you to authenticate, and
594to push your changes back with the C<camel> remote:
595
596 % git fetch camel
597 % git push camel
598
599The C<fetch> command just updates the C<camel> refs, as the objects
600themselves should have been fetched when pulling from C<origin>.
04baf1ff 601
99cd8e46 602=head2 Accepting a patch
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603
604If you have received a patch file generated using the above section,
605you should try out the patch.
606
607First we need to create a temporary new branch for these changes and
608switch into it:
609
610 % git checkout -b experimental
611
612Patches that were formatted by C<git format-patch> are applied with
613C<git am>:
614
615 % git am 0001-Rename-Leon-Brocard-to-Orange-Brocard.patch
616 Applying Rename Leon Brocard to Orange Brocard
617
618If just a raw diff is provided, it is also possible use this two-step
619process:
620
621 % git apply bugfix.diff
622 % git commit -a -m "Some fixing" --author="That Guy <that.guy@internets.com>"
edcf105d 623
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624Now we can inspect the change:
625
626 % git show HEAD
627 commit b1b3dab48344cff6de4087efca3dbd63548ab5e2
628 Author: Leon Brocard <acme@astray.com>
629 Date: Fri Dec 19 17:02:59 2008 +0000
630
631 Rename Leon Brocard to Orange Brocard
632
633 diff --git a/AUTHORS b/AUTHORS
634 index 293dd70..722c93e 100644
635 --- a/AUTHORS
636 +++ b/AUTHORS
637 @@ -541,7 +541,7 @@ Lars Hecking <lhecking@nmrc.ucc.ie>
638 Laszlo Molnar <laszlo.molnar@eth.ericsson.se>
639 Leif Huhn <leif@hale.dkstat.com>
640 Len Johnson <lenjay@ibm.net>
641 -Leon Brocard <acme@astray.com>
642 +Orange Brocard <acme@astray.com>
643 Les Peters <lpeters@aol.net>
644 Lesley Binks <lesley.binks@gmail.com>
645 Lincoln D. Stein <lstein@cshl.org>
646
647If you are a committer to Perl and you think the patch is good, you can
648then merge it into blead then push it out to the main repository:
649
650 % git checkout blead
651 % git merge experimental
68382b67 652 % git push origin blead
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653
654If you want to delete your temporary branch, you may do so with:
655
656 % git checkout blead
657 % git branch -d experimental
658 error: The branch 'experimental' is not an ancestor of your current HEAD.
659 If you are sure you want to delete it, run 'git branch -D experimental'.
660 % git branch -D experimental
661 Deleted branch experimental.
662
663=head2 Committing to blead
664
665The 'blead' branch will become the next production release of Perl.
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666
667Before pushing I<any> local change to blead, it's incredibly important
668that you do a few things, lest other committers come after you with
669pitchforks and torches:
670
671=over
672
673=item *
674
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675Make sure you have a good commit message. See L<perlhack/Commit
676message> for details.
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677
678=item *
679
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680Run the test suite. You might not think that one typo fix would break a
681test file. You'd be wrong. Here's an example of where not running the
682suite caused problems. A patch was submitted that added a couple of
683tests to an existing .t. It couldn't possibly affect anything else, so
f76a37ee
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684no need to test beyond the single affected .t, right? But, the
685submitter's email address had changed since the last of their
04c692a8 686submissions, and this caused other tests to fail. Running the test
f76a37ee 687target given in the next item would have caught this problem.
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688
689=item *
690
691If you don't run the full test suite, at least C<make test_porting>.
692This will run basic sanity checks. To see which sanity checks, have a
693look in F<t/porting>.
694
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695=item *
696
697If you make any changes that affect miniperl or core routines that have
04baf1ff 698different code paths for miniperl, be sure to run C<make minitest>.
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699This will catch problems that even the full test suite will not catch
700because it runs a subset of tests under miniperl rather than perl.
701
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702=back
703
99cd8e46 704=head2 On merging and rebasing
961bfa8c
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705
706Simple, one-off commits pushed to the 'blead' branch should be simple
707commits that apply cleanly. In other words, you should make sure your
708work is committed against the current position of blead, so that you can
709push back to the master repository without merging.
710
711Sometimes, blead will move while you're building or testing your
712changes. When this happens, your push will be rejected with a message
713like this:
714
715 To ssh://perl5.git.perl.org/perl.git
716 ! [rejected] blead -> blead (non-fast-forward)
717 error: failed to push some refs to 'ssh://perl5.git.perl.org/perl.git'
718 To prevent you from losing history, non-fast-forward updates were rejected
719 Merge the remote changes (e.g. 'git pull') before pushing again. See the
720 'Note about fast-forwards' section of 'git push --help' for details.
721
722When this happens, you can just I<rebase> your work against the new
723position of blead, like this (assuming your remote for the master
724repository is "p5p"):
725
726 $ git fetch p5p
727 $ git rebase p5p/blead
728
729You will see your commits being re-applied, and you will then be able to
c9d1da35 730push safely. More information about rebasing can be found in the
961bfa8c
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731documentation for the git-rebase(1) command.
732
733For larger sets of commits that only make sense together, or that would
734benefit from a summary of the set's purpose, you should use a merge
735commit. You should perform your work on a L<topic branch|/Topic
736branches and rewriting history>, which you should regularly rebase
737against blead to ensure that your code is not broken by blead moving.
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738When you have finished your work, please perform a final rebase and
739test. Linear history is something that gets lost with every
740commit on blead, but a final rebase makes the history linear
741again, making it easier for future maintainers to see what has
742happened. Rebase as follows (assuming your work was on the
688cbe00 743branch C<< committer/somework >>):
961bfa8c 744
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745 $ git checkout committer/somework
746 $ git rebase blead
747
748Then you can merge it into master like this:
749
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750 $ git checkout blead
751 $ git merge --no-ff --no-commit committer/somework
752 $ git commit -a
753
754The switches above deserve explanation. C<--no-ff> indicates that even
755if all your work can be applied linearly against blead, a merge commit
756should still be prepared. This ensures that all your work will be shown
757as a side branch, with all its commits merged into the mainstream blead
758by the merge commit.
759
760C<--no-commit> means that the merge commit will be I<prepared> but not
761I<committed>. The commit is then actually performed when you run the
762next command, which will bring up your editor to describe the commit.
763Without C<--no-commit>, the commit would be made with nearly no useful
764message, which would greatly diminish the value of the merge commit as a
765placeholder for the work's description.
766
767When describing the merge commit, explain the purpose of the branch, and
768keep in mind that this description will probably be used by the
769eventual release engineer when reviewing the next perldelta document.
770
04c692a8 771=head2 Committing to maintenance versions
9d68b7ed 772
77db6475
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773Maintenance versions should only be altered to add critical bug fixes,
774see L<perlpolicy>.
7f4ffa9d 775
9d68b7ed
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776To commit to a maintenance version of perl, you need to create a local
777tracking branch:
778
779 % git checkout --track -b maint-5.005 origin/maint-5.005
780
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781This creates a local branch named C<maint-5.005>, which tracks the
782remote branch C<origin/maint-5.005>. Then you can pull, commit, merge
783and push as before.
b0d36535 784
f755e97d 785You can also cherry-pick commits from blead and another branch, by
0549aefb
LB
786using the C<git cherry-pick> command. It is recommended to use the
787B<-x> option to C<git cherry-pick> in order to record the SHA1 of the
788original commit in the new commit message.
f755e97d 789
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790Before pushing any change to a maint version, make sure you've
791satisfied the steps in L</Committing to blead> above.
edcf105d 792
04c692a8 793=head2 Merging from a branch via GitHub
bdaf0bc6 794
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795While we don't encourage the submission of patches via GitHub, that
796will still happen. Here is a guide to merging patches from a GitHub
797repository.
bdaf0bc6 798
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799 % git remote add avar git://github.com/avar/perl.git
800 % git fetch avar
041325d6 801
04c692a8 802Now you can see the differences between the branch and blead:
705c800c 803
04c692a8 804 % git diff avar/orange
705c800c 805
04c692a8 806And you can see the commits:
041325d6 807
04c692a8 808 % git log avar/orange
f755e97d 809
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810If you approve of a specific commit, you can cherry pick it:
811
812 % git cherry-pick 0c24b290ae02b2ab3304f51d5e11e85eb3659eae
813
814Or you could just merge the whole branch if you like it all:
815
816 % git merge avar/orange
817
818And then push back to the repository:
819
68382b67 820 % git push origin blead
04c692a8 821
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822=head2 Using a smoke-me branch to test changes
823
824Sometimes a change affects code paths which you cannot test on the OSes
825which are directly available to you and it would be wise to have users
826on other OSes test the change before you commit it to blead.
827
828Fortunately, there is a way to get your change smoke-tested on various
829OSes: push it to a "smoke-me" branch and wait for certain automated
830smoke-testers to report the results from their OSes.
831
832The procedure for doing this is roughly as follows (using the example of
833of tonyc's smoke-me branch called win32stat):
834
835First, make a local branch and switch to it:
836
837 % git checkout -b win32stat
838
839Make some changes, build perl and test your changes, then commit them to
840your local branch. Then push your local branch to a remote smoke-me
841branch:
842
843 % git push origin win32stat:smoke-me/tonyc/win32stat
844
845Now you can switch back to blead locally:
846
847 % git checkout blead
848
849and continue working on other things while you wait a day or two,
850keeping an eye on the results reported for your smoke-me branch at
851L<http://perl.develop-help.com/?b=smoke-me/tonyc/win32state>.
852
853If all is well then update your blead branch:
854
855 % git pull
856
857then checkout your smoke-me branch once more and rebase it on blead:
858
859 % git rebase blead win32stat
860
861Now switch back to blead and merge your smoke-me branch into it:
862
863 % git checkout blead
864 % git merge win32stat
865
866As described earlier, if there are many changes on your smoke-me branch
867then you should prepare a merge commit in which to give an overview of
868those changes by using the following command instead of the last
869command above:
870
871 % git merge win32stat --no-ff --no-commit
872
873You should now build perl and test your (merged) changes one last time
874(ideally run the whole test suite, but failing that at least run the
875F<t/porting/*.t> tests) before pushing your changes as usual:
876
877 % git push origin blead
878
879Finally, you should then delete the remote smoke-me branch:
880
881 % git push origin :smoke-me/tonyc/win32stat
882
883(which is likely to produce a warning like this, which can be ignored:
884
1dcc3c19
DG
885 remote: fatal: ambiguous argument 'refs/heads/smoke-me/tonyc/win32stat':
886 unknown revision or path not in the working tree.
3afc3118
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887 remote: Use '--' to separate paths from revisions
888
889) and then delete your local branch:
890
891 % git branch -d win32stat
892
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893=head2 A note on camel and dromedary
894
895The committers have SSH access to the two servers that serve
896C<perl5.git.perl.org>. One is C<perl5.git.perl.org> itself (I<camel>),
897which is the 'master' repository. The second one is
898C<users.perl5.git.perl.org> (I<dromedary>), which can be used for
899general testing and development. Dromedary syncs the git tree from
900camel every few minutes, you should not push there. Both machines also
901have a full CPAN mirror in /srv/CPAN, please use this. To share files
902with the general public, dromedary serves your ~/public_html/ as
903C<http://users.perl5.git.perl.org/~yourlogin/>
904
905These hosts have fairly strict firewalls to the outside. Outgoing, only
906rsync, ssh and git are allowed. For http and ftp, you can use
907http://webproxy:3128 as proxy. Incoming, the firewall tries to detect
908attacks and blocks IP addresses with suspicious activity. This
909sometimes (but very rarely) has false positives and you might get
910blocked. The quickest way to get unblocked is to notify the admins.
911
912These two boxes are owned, hosted, and operated by booking.com. You can
913reach the sysadmins in #p5p on irc.perl.org or via mail to
914C<perl5-porters@perl.org>.