1 @c -*- coding: utf-8; mode: texinfo; -*-
4 @node Working with source code
5 @chapter Working with source code
7 New contributors should only read @ref{Using lily-git}. Please
8 ignore the rest of this chapter.
10 Advanced contributors will find the rest of this material quite
11 useful, particularly if they are working on major new features.
16 * Basic Git procedures::
17 * Advanced Git procedures::
19 * Repository directory structure::
20 * Other Git documentation::
24 @c if you change this node name, you'll need to change the @ref in
25 @c web/ and/or included/, along with all the translations.
27 @section Using lily-git
29 @command{lily-git.tcl} is a graphical tool to help you access and
30 share changes to the lilypond source code.
33 * Install and configuration of lily-git.tcl::
34 * Daily use of lily-git.tcl::
37 @node Install and configuration of lily-git.tcl
38 @unnumberedsubsec Install and configuration of @command{lily-git.tcl}
42 If you haven't already, download and install Git.
47 Lilybuntu users: git has already been installed for you.
49 @item Windows users: download the @code{.exe} file labeled
50 @qq{Full installer for official Git} from:
53 @uref{http://code.google.com/p/msysgit/downloads/list}
56 @item Other operating systems: either install @command{git} with
57 your package manager, or download it from the @qq{Binaries}
61 @uref{http://git-scm.com/download}
68 Download the @command{lily-git.tcl} script from:
70 @c don't change the cgit link below to gitweb; gitweb uses
71 @c long filenames like "scripts_auxiliar_lily-git.tcl"
74 @uref{http://git.sv.gnu.org/cgit/lilypond.git/plain/scripts/auxiliar/lily-git.tcl}
78 To run the program from the command line, navigate to the
79 directory containing @command{lily-git.tcl} and enter:
86 Click on the @qq{Get source} button.
88 This will create a directory called @file{lilypond-git/} within
89 your home directory, and will download the source code into that
90 directory (around 55Mb). When the process is finished, the
91 @qq{Command output} window will display @qq{Done}, and the button
92 label will change to say @qq{Update source}.
95 Navigate to the @file{lilypond-git/} directory to view the source
96 files. You should now be able to modify the source files using
97 your normal text editor.
102 Advanced note: The @qq{Get source} button does not fetch the
103 entire history of the git repository, so utilities like
104 @command{gitk} will only be able to display the most recent
105 additions. As you continue to work with @command{lily-git.tcl}, the
106 @qq{Update source} button will take any new additions and add it
107 to whatever is currently in your repository's history.
111 @node Daily use of lily-git.tcl
112 @unnumberedsubsec Daily use of @command{lily-git.tcl}
114 @warning{Only work on one set of changes at once. Do not start
115 work on any new changes until your first set has been accepted.}
117 @subsubheading 1. Update source
119 At the beginning of each session of lilypond work, you should
120 click the @qq{Update source} button to get the latest changes to
123 @warning{In some rare and unfortunate circumstances, this will
124 result in a @emph{merge conflict}. If this occurs, follow the
125 instructions for @qq{Abort changes}, below. Your work will not be
129 @subsubheading 2a. New local commit
131 A single commit typically represents one logical set of related
132 changes (such as a bug-fix), and may incorporate changes to
133 multiple files at the same time.
135 When you're finished making the changes for a commit, click the
136 @qq{New local commit} button. This will open the @qq{Git Commit
137 Message} window. The message header is required, and the message
140 After entering a commit message, click @qq{OK} to finalize the
144 Advanced note: For more information regarding commits and commit
145 messages, see @ref{Commits and patches}.
149 @subsubheading 2b. Amend previous commit
151 You can go back and make changes to the most recent commit with
152 the @qq{Amend previous commit} button. This is useful if a
153 mistake is found after you have clicked the @qq{New local commit}
156 To amend the most recent commit, re-edit the source files as
157 needed and then click the @qq{Amend previous commit} button. The
158 earlier version of the commit is not saved, but is replaced by the
161 @warning{This does not update the patch @strong{files}; if you
162 have a patch file from an earlier version of the commit, you will
163 need to make another patch set when using this feature. The old
164 patch file will not be saved, but will be replaced by the new one
165 after you click on @qq{Make patch set}.}
168 @subsubheading 3. Make patch set
170 Before making a patch set from any commits, you should click the
171 @qq{Update source} button to make sure the commits are based on
172 the most recent remote snapshot.
174 When you click the @qq{Make patch set} button,
175 @command{lily-git.tcl} will produce patch files for any new
176 commits, saving them to the current directory. The command output
177 will display the name of the new patch files near the end of the
181 0001-CG-add-lily-git-instructions.patch
185 Send patch files to the appropriate place:
189 If you have a mentor, send it to them via email.
192 New contributors should send the patch attached to an email (must
193 be less than 64KB) to @email{frogs@@lilynet.net}.
196 Translators should send patches to
197 @email{translations@@lilynet.net}.
200 More experienced contributors should upload the patch for
201 web-based review. This requires additional software and use of
202 the command-line; see @ref{Uploading a patch for review}.
207 @subsubheading The @qq{Abort changes -- Reset to origin} button
209 @warning{Only use this if your local commit history gets
210 hopelessly confused!}
212 The button labeled @qq{Abort changes -- Reset to origin} will copy
213 all changed files to a subdirectory of @file{lilypond-git/} named
214 @file{aborted_edits/}, and will reset the repository to the
215 current state of the remote repository (at @code{git.sv.gnu.org}).
218 @node Starting with Git
219 @section Starting with Git
222 Using the Git program directly (as opposed to using the
223 @command{lily-git.tcl} GUI) allows you to have much greater control
224 over the contributing process. You should consider using Git if
225 you want to work on complex projects, or if you want to work on
226 multiple projects concurrently.
231 * Downloading remote branches::
236 @subsection Setting up
239 TODO: Remove this note if incorporating Windows instructions
240 throughout this section:
242 @warning{These instructions assume that you are using the
243 command-line version of Git 1.5 or higher. Windows users should
244 skip to @ref{Git on Windows}.}
248 * Initializing a repository::
254 @unnumberedsubsubsec Installing Git
257 If you are using a Unix-based machine, the easiest way to download
258 and install Git is through a package manager such as @command{rpm}
259 or @command{apt-get}---the installation is generally automatic.
260 The only required package is (usually) called @command{git-core},
261 although some of the auxiliary @command{git@var{*}} packages are
262 also useful (such as @command{gitk}).
264 Alternatively, you can visit the Git website
265 (@uref{http://git-scm.com/}) for downloadable binaries and
268 TODO: add Windows installation instructions (or @@ref@{Git on
272 @node Initializing a repository
273 @unnumberedsubsubsec Initializing a repository
276 Once Git is installed, you'll need to create a new directory where
277 your initial repository will be stored (the example below uses
278 @file{~/lilypond-git/}, where @code{~} represents your home
279 directory). Run @command{git@tie{}init} from within the new
280 directory to initialize an empty repository:
283 mkdir ~/lilypond-git/; cd ~/lilypond-git/
287 @subsubheading Technical details
289 This creates (within the @file{~/lilypond-git/} directory) a
290 subdirectory called @file{.git/}, which Git uses to keep track of
291 changes to the repository, among other things. Normally you don't
292 need to access it, but it's good to know it's there.
295 @node Configuring Git
296 @unnumberedsubsubsec Configuring Git
298 @warning{Throughout the rest of this manual, all command-line
299 input should be entered from the top directory of the Git
300 repository being discussed (eg. @file{~/lilypond-git/}). This is
301 referred to as a @emph{top source directory}.}
303 Before downloading a copy of the main LilyPond repository, you
304 should configure some basic settings with the
305 @command{git@tie{}config} command. Git allows you to set both
306 global and repository-specific options.
308 To configure settings that affect all repositories, use the
309 @command{--global} command line option. For example, the first
310 two options that you should always set are your @var{name} and
311 @var{email}, since Git needs these to keep track of commit
315 git config --global user.name "@var{John Smith}"
316 git config --global user.email @var{john@@example.com}
319 To configure Git to use colored output where possible, use:
322 git config --global color.ui auto
325 The text editor that opens when using @command{git@tie{}commit}
326 can also be changed. If none of your editor-related environment
327 variables are set ($GIT_EDITOR, $VISUAL, or $EDITOR), the default
328 editor is usually @command{vi} or @command{vim}. If you're not
329 familiar with either of these, you should probably change the
330 default to an editor that you know how to use. For example, to
331 change the default editor to @command{nano}, enter:
334 git config --global core.editor @var{nano}
337 TODO: Add instructions for changing the editor on Windows, which
338 is a little different, I think. -mp
340 @subsubheading Technical details
342 Git stores the information entered with
343 @command{git@tie{}config@tie{}--global} in the file
344 @file{.gitconfig}, located in your home directory. This file can
345 also be modified directly, without using
346 @command{git@tie{}config}. The @file{.gitconfig} file generated
347 by the above commands would look like this:
352 email = john@@example.com
359 Using the @command{git@tie{}config} command @emph{without} the
360 @command{--global} option configures repository-specific settings,
361 which are stored in the file @file{.git/config}. This file is
362 created when a repository is initialized (using
363 @command{git@tie{}init}), and by default contains these lines:
367 repositoryformatversion = 0
370 logallrefupdates = true
373 However, since different repository-specific options are
374 recommended for different development tasks, it is best to avoid
375 setting any now. Specific recommendations will be mentioned later
379 @node Downloading remote branches
380 @subsection Downloading remote branches
384 * Organization of remote branches::
385 * LilyPond repository sources::
386 * Downloading individual branches::
387 * Downloading all remote branches::
392 @node Organization of remote branches
393 @unnumberedsubsubsec Organization of remote branches
396 The main LilyPond repository is organized into @emph{branches} to
397 facilitate development. These are often called @emph{remote}
398 branches to distinguish them from @emph{local} branches you might
399 create yourself (see @ref{Using local branches}).
401 The @code{master} branch contains all the source files used to
402 build LilyPond, which includes the program itself (both stable and
403 development releases), the documentation (and its translations),
404 and the website. Generally, the @code{master} branch is expected
405 to compile successfully.
407 The @code{lilypond/translation} branch is a side branch that
408 allows translators to work without needing to worry about
409 compilation problems. Periodically, the Translation Meister
410 (after verifying that it doesn't break compilation), will
411 @emph{merge} this branch back into @code{master} to incorporate
412 recent translations. Similarly, the @code{master} branch is
413 usually merged into the @code{lilypond/translation} branch after
414 significant changes to the English documentation. See
415 @ref{Translating the documentation} for details.
418 @node LilyPond repository sources
419 @unnumberedsubsubsec LilyPond repository sources
422 The recommended source for downloading a copy of the main
426 git://git.sv.gnu.org/lilypond.git
429 However, if your internet router filters out connections using the
430 GIT protocol, or if you experience difficulty connecting via GIT,
431 you can try these other sources:
434 ssh://git.sv.gnu.org/srv/git/lilypond.git
435 http://git.sv.gnu.org/r/lilypond.git
438 The SSH protocol can only be used if your system is properly set
439 up to use it. Also, the HTTP protocol is slowest, so it should
440 only be used as a last resort.
443 @node Downloading individual branches
444 @unnumberedsubsubsec Downloading individual branches
447 Once you have initialized an empty Git repository on your system
448 (see @ref{Initializing a repository}), you can download a remote
449 branch into it. Make sure you know which branch you want to start
452 To download the @code{master} branch, enter the following:
455 git remote add -ft master -m master \
456 origin git://git.sv.gnu.org/lilypond.git/
459 To download the @code{lilypond/translation} branch, enter:
462 git remote add -ft lilypond/translation -m \
463 lilypond/translation origin git://git.sv.gnu.org/lilypond.git/
466 The @command{git@tie{}remote@tie{}add} process could take up to
467 ten minutes, depending on the speed of your connection. The
468 output will be something like this:
472 remote: Counting objects: 235967, done.
473 remote: Compressing objects: 100% (42721/42721), done.
474 remote: Total 235967 (delta 195098), reused 233311 (delta 192772)
475 Receiving objects: 100% (235967/235967), 68.37 MiB | 479 KiB/s, done.
476 Resolving deltas: 100% (195098/195098), done.
477 From git://git.sv.gnu.org/lilypond
478 * [new branch] master -> origin/master
479 From git://git.sv.gnu.org/lilypond
480 * [new tag] flower/1.0.1 -> flower/1.0.1
481 * [new tag] flower/1.0.10 -> flower/1.0.10
483 * [new tag] release/2.9.6 -> release/2.9.6
484 * [new tag] release/2.9.7 -> release/2.9.7
487 When @command{git@tie{}remote@tie{}add} is finished, the remote
488 branch should be downloaded into your repository---though not yet
489 in a form that you can use. In order to browse the source code
490 files, you need to @emph{create} and @emph{checkout} your own
491 local branch. In this case, however, it is easier to have Git
492 create the branch automatically by using the @command{checkout}
493 command on a non-existent branch. Enter the following:
496 git checkout -b @var{branch} origin/@var{branch}
500 where @code{@var{branch}} is the name of your tracking branch,
501 either @code{master} or @code{lilypond/translation}.
503 Git will issue some warnings; this is normal:
506 warning: You appear to be on a branch yet to be born.
507 warning: Forcing checkout of origin/master.
508 Branch master set up to track remote branch master from origin.
512 By now the source files should be accessible---you should be able
513 to edit any files in the @file{lilypond-git/} directory using a
514 text editor of your choice. But don't start just yet! Before
515 editing any source files, learn how to keep your changes organized
516 and prevent problems later---read @ref{Basic Git procedures}.
518 @subsubheading Technical Details
520 The @command{git@tie{}remote@tie{}add} command should add some
521 lines to your local repository's @file{.git/config} file:
525 url = git://git.sv.gnu.org/lilypond.git/
526 fetch = +refs/heads/master:refs/remotes/origin/master
530 @node Downloading all remote branches
531 @unnumberedsubsubsec Downloading all remote branches
534 To download all remote branches at once, you can @command{clone}
535 the entire repository:
538 git clone git://git.sv.gnu.org/lilypond.git
543 @unnumberedsubsubsec Other branches
545 Most contributors will never need to touch the other branches. If
546 you wish to do so, you will need more familiarity with Git; please
547 see @ref{Other Git documentation}.
550 @item @code{dev/XYZ}:
551 These branches are for individual developers. They store code
552 which is not yet stable enough to be added to the @code{master}
555 @item @code{stable/XYZ}:
556 The branches are kept for archival reasons.
560 Another item of interest might be the Grand Unified Builder, our
561 cross-platform building tool. Since it is used by projects as
562 well, it is not stored in our gub repository. For more info, see
563 @uref{http://lilypond.org/gub}. The git location is
564 @uref{http://github.com/janneke/gub}.
567 @node Basic Git procedures
568 @section Basic Git procedures
572 * The Git contributor's cycle::
573 * Pulling and rebasing::
574 * Using local branches::
575 * Commits and patches::
579 @node The Git contributor's cycle
580 @subsection The Git contributor's cycle
583 Here is a simplified view of the contribution process on Git:
587 Update your local repository by @emph{pulling} the most recent
588 updates from the remote repository.
591 Edit source files within your local repository's @emph{working
595 @emph{Commit} the changes you've made to a local @emph{branch}.
598 Generate a @emph{patch} to share your changes with the developers.
602 @node Pulling and rebasing
603 @subsection Pulling and rebasing
606 When developers push new patches to the @code{git.sv.gnu.org}
607 repository, your local repository is @strong{not} automatically
608 updated. It is important to keep your repository up-to-date by
609 periodically @emph{pulling} the most recent @emph{commits} from
610 the remote branch. Developers expect patches to be as current as
611 possible, since outdated patches require extra work before they
614 Occasionally you may need to rework some of your own modifications
615 to match changes made to the remote branch (see @ref{Resolving
616 conflicts}), and it's considerably easier to rework things
617 incrementally. If you don't update your repository along the way,
618 you may have to spend a lot of time resolving branch conflicts and
619 reconfiguring much of the work you've already done.
621 Fortunately, Git is able to resolve certain types of branch
622 conflicts automatically with a process called @emph{rebasing}.
623 When rebasing, Git tries to modify your old commits so they appear
624 as new commits (based on the latest updates). For a more involved
625 explanation, see the @command{git-rebase} man page.
627 To pull without rebasing (recommended for translators), use the
631 git pull # recommended for translators
634 If you're tracking the remote @code{master} branch, you should add
635 the @code{-r} option (short for @code{--rebase}) to keep commits
636 on your local branch current:
639 git pull -r # use with caution when translating
642 If you don't edit translated documentation and don't want to type
643 @code{-r} every time, configure the master branch to rebase by
644 default with this command:
647 git config branch.master.rebase true
650 If pull fails because of a message like
653 error: Your local changes to 'Documentation/learning/tutorial.itely'
654 would be overwritten by merge. Aborting.
661 Documentation/learning/tutorial.itely: needs update
662 refusing to pull with rebase: your working tree is not up-to-date
666 it means that you have modified some files in you working tree
667 without committing changes (see @ref{Commits and patches}); you
668 can use the @command{git@tie{}stash} command to work around this:
671 git stash # save uncommitted changes
672 git pull -r # pull using rebase (translators omit "-r")
673 git stash pop # reapply previously saved changes
676 Note that @command{git@tie{}stash@tie{}pop} will try to apply a
677 patch, and this may create a conflict. If this happens, see
678 @ref{Resolving conflicts}.
680 TODO: I think the next paragraph is confusing. Perhaps prepare
681 the reader for new terms `committish' and `head'? -mp
683 @warning{translators and documentation editors, if you have
684 changed committishes in the head of translated files using commits
685 you have not yet pushed to @code{git.sv.gnu.org}, please do not
686 rebase. If you want to avoid wondering whether you should rebase
687 each time you pull, please always use committishes from master
688 and/or lilypond/translation branch on @code{git.sv.gnu.org}, which
689 in particular implies that you must push your changes to
690 documentation except committishes updates (possibly after having
691 rebased), then update the committishes and push them.}
693 TODO: when committishes automatic conditional update have been
694 tested and documented, append the following to the warning above:
695 Note that using update-committishes make target generally touches
698 @subsubheading Technical details
700 The @command{git@tie{}config} command mentioned above adds the
701 line @code{rebase = true} to the master branch in your local
702 repository's @file{.git/config} file:
707 merge = refs/heads/master
712 @node Using local branches
713 @subsection Using local branches
717 * Creating and removing branches::
718 * Listing branches and remotes::
719 * Checking out branches::
724 @node Creating and removing branches
725 @unnumberedsubsubsec Creating and removing branches
728 Local branches are useful when you're working on several different
729 projects concurrently. To create a new branch, enter:
732 git branch @var{name}
735 To delete a branch, enter:
738 git branch -d @var{name}
741 Git will ask you for confirmation if it sees that data would be
742 lost by deleting the branch. Use @code{-D} instead of @code{-d}
743 to bypass this. Note that you cannot delete a branch if it is
744 currently checked out.
747 @node Listing branches and remotes
748 @unnumberedsubsubsec Listing branches and remotes
750 You can get the exact path or URL of all remote branches by
757 To list Git branches on your local repositories, run
760 git branch # list local branches only
761 git branch -r # list remote branches
762 git branch -a # list all branches
766 @node Checking out branches
767 @unnumberedsubsubsec Checking out branches
769 To know the currently checked out branch, i.e. the branch whose
770 source files are present in your working tree, read the first line
778 The currently checked out branch is also marked with an asterisk
779 in the output of @command{git branch}.
781 You can check out another branch @code{@var{other_branch}}, i.e.
782 check out @code{@var{other_branch}} to the working tree, by
786 git checkout @var{other_branch}
789 Note that it is possible to check out another branch while having
790 uncommitted changes, but it is not recommended unless you know
791 what you are doing; it is recommended to run @command{git status}
792 to check this kind of issue before checking out another branch.
794 @node Merging branches
795 @unnumberedsubsubsec Merging branches
797 To merge branch @code{@var{foo}} into branch @code{@var{bar}},
798 i.e. to @qq{add} all changes made in branch @code{@var{foo}} to
799 branch @code{@var{bar}}, run
802 git checkout @var{bar}
806 If any conflict happens, see @ref{Resolving conflicts}.
808 There are common usage cases for merging: as a translator, you
809 will often want to merge @code{master} into
810 @code{lilypond/translation}; on the other hand, the Translations
811 meister wants to merge @code{lilypond/translation} into
812 @code{master} whenever he has checked that
813 @code{lilypond/translation} builds successfully.
816 @node Commits and patches
817 @subsection Commits and patches
821 * Understanding commits::
825 * Uploading a patch for review::
829 @node Understanding commits
830 @unnumberedsubsubsec Understanding commits
832 Technically, a @emph{commit} is a single point in the history of a
833 branch, but most developers use the term to mean a @emph{commit
834 object}, which stores information about a particular revision. A
835 single commit can record changes to multiple source files, and
836 typically represents one logical set of related changes (such as a
837 bug-fix). You can list the ten most recent commits in your
838 current branch with this command:
841 git log -10 --oneline
844 If you're using an older version of Git and get an @q{unrecognized
845 argument} error, use this instead:
848 git log -10 --pretty=oneline --abbrev-commit
851 More interactive lists of the commits on the remote @code{master}
852 branch are available at
853 @uref{http://git.sv.gnu.org/gitweb/?p=lilypond.git;a=shortlog} and
854 @uref{http://git.sv.gnu.org/cgit/lilypond.git/log/}.
858 @unnumberedsubsubsec Making commits
861 Once you have modified some source files in your working
862 directory, you can make a commit with the following procedure:
866 Make sure you've configured Git properly (see @ref{Configuring
867 Git}). Check that your changes meet the requirements described in
868 @ref{Code style} and/or @ref{Documentation policy}. For advanced
869 edits, you may also want to verify that the changes don't break
870 the compilation process.
873 Run the following command:
880 to make sure you're on the right branch, and to see which files
881 have been modified, added or removed, etc. You may need to tell
882 Git about any files you've added by running one of these:
885 git add @var{file} # add untracked @var{file} individually
886 git add . # add all untracked files in current directory
890 After @command{git@tie{}add}, run @command{git@tie{}status} again
891 to make sure you got everything. You may also need to modify
895 Preview the changes about to be committed (to make sure everything
903 The @code{HEAD} argument refers to the most recent commit on the
904 currently checked-out branch.
907 Generate the commit with:
914 The @code{-a} is short for @code{--all} which includes modified
915 and deleted files, but only those newly created files that have
916 previously been added.
921 @node Commit messages
922 @unnumberedsubsubsec Commit messages
925 When you run the @command{git@tie{}commit@tie{}-a} command, Git
926 automatically opens the default text editor so you can enter a
927 @emph{commit message}. If you find yourself in a foreign editing
928 environment, you're probably in @command{vi} or @command{vim}. If
929 you want to switch to an editor you're more familiar with, quit by
930 typing @code{:q!} and pressing @code{<Enter>}. See
931 @ref{Configuring Git} for instructions on changing the default
934 In any case, Git will open a text file for your commit message
935 that looks like this:
939 # Please enter the commit message for your changes. Lines starting
940 # with '#' will be ignored, and an empty message aborts the commit.
942 # Changes to be committed:
943 # (use "git reset HEAD <file>..." to unstage)
945 # modified: working.itexi
949 Your commit message should begin with a one-line summary
950 describing the change (no more than 50 characters long), and if
951 necessary a blank line followed by several lines giving the
954 @c $ git log -1 --pretty=medium 4d6f1e5
956 Doc: add Baerenreiter and Henle solo cello suites
958 Added comparison of solo cello suite engravings to new essay with
959 high-res images, fixed cropping on Finale example.
962 Commit messages often start with a short prefix describing the
963 general location of the changes. If a commit affects the
964 documentation in English (or in several languages simultaneously)
965 the commit message should be prefixed with @qq{Doc:@tie{}}. If
966 the commit affects only one of the translations, the commit
967 message should be prefixed with @qq{Doc-@var{**}:@tie{}}, where
968 @var{**} is the two-letter language code. Commits that affect the
969 website should use @qq{Web:@tie{}} for English, and
970 @qq{Web-@var{**}:@tie{}} for the other languages. Also, changes
971 to a single file are often prefixed with the name of the file
972 involved. Visit the links listed in @ref{Understanding commits}
977 @unnumberedsubsubsec Making patches
979 If you want to share your changes with other contributors and
980 developers, you need to generate @emph{patches} from your commits.
981 We prefer it if you follow the instructions in
982 @ref{Uploading a patch for review}. However, we present an
983 alternate method here.
985 You should always run @command{git@tie{}pull@tie{}-r} (translators
986 should leave off the @code{-r}) before doing this to ensure that
987 your patches are as current as possible.
989 Once you have made one or more commits in your local repository,
990 and pulled the most recent commits from the remote branch, you can
991 generate patches from your local commits with the command:
994 git format-patch origin
997 The @code{origin} argument refers to the remote tracking branch at
998 @code{git.sv.gnu.org}. This command generates a separate patch
999 for each commit that's in the current branch but not in the remote
1000 branch. Patches are placed in the current working directory and
1001 will have names that look something like this:
1004 0001-Doc-Fix-typos.patch
1005 0002-Web-Remove-dead-links.patch
1009 Send an email (must be less than 64 KB) to
1010 @email{lilypond-devel@@gnu.org} briefly explaining your work, with
1011 the patch files attached. Translators should send patches to
1012 @email{translations@@lilynet.net}. After your patches are
1013 reviewed, the developers may push one or more of them to the main
1014 repository or discuss them with you.
1017 @node Uploading a patch for review
1018 @unnumberedsubsubsec Uploading a patch for review
1020 Any non-trivial change should be uploaded to our @qq{Rietveld}
1021 code review website:
1024 @uref{http://codereview.appspot.com/}
1027 @subsubheading Initial setup
1032 You must have a gmail account.
1035 Install @command{git-cl} by entering:
1038 git clone git://neugierig.org/git-cl.git
1042 Add the @file{git-cl/} directory to your PATH, or create a
1043 symbolic link to the @command{git-cl} and @command{upload.py}
1044 scripts in one of your PATH directories (such as
1049 Move into the top source directory and then configure
1050 @command{git cl}. If you do not understand any question, just
1051 answer with a newline (CR).
1054 cd $HOME/lilypond-git/
1060 @subsubheading Uploading patch set
1062 @warning{Unless you are familiar with branches, only work on one
1063 set of changes at once.}
1065 There are two methods, depending on your git setup.
1069 @strong{Master branch}: (easy option, and used in @command{lily-git.tcl})
1071 If you added your patch to @code{master}, then:
1075 git cl upload origin/master
1078 If you have git push ability, make sure that you @emph{remove}
1079 your patch (with @command{git rebase} or @command{git reset})
1080 before pushing other stuff.
1083 @strong{Separate branch}: (complicated option)
1085 Ensure your changes are committed in a separate branch, which
1086 should differ from the reference branch to be used by just the
1087 changes to be uploaded. If the reference branch is to be
1088 origin/master, ensure this is up-to-date. If necessary, use git
1089 rebase to rebase the branch containing the changes to the head of
1090 origin/master. Finally, check out branch with the changes and
1094 git cl upload <reference SHA1 ID>
1098 where <reference SHA1 ID> is the SHA1 ID of the commit to be used
1099 as a reference source for the patch. Generally, this will be the
1100 SHA1 ID of origin/master, and in that case the command:
1103 git cl upload origin/master
1111 After prompting for your Google email address and password, the
1112 patch set will be posted to Rietveld.
1114 @subsubheading Announcing your patch set
1116 You should then announce the patch by sending an email to
1117 @code{lilypond-devel}, with a subject line starting with PATCH:,
1118 asking for comments on the patch. Alternately, you may Publish +
1119 Mail a (bogus) comment, in order to send an email to
1122 @subsubheading Revisions
1124 As revisions are made in response to comments, successive patch sets
1125 for the same issue can be uploaded by reissuing the git-cl command
1126 with the modified branch checked out.
1128 Sometimes in response to comments on revisions, the best way to
1129 work may require creation of a new branch in git. In order to
1130 associate the new branch with an existing Rietveld issue,
1131 the following command can be used:
1134 git cl issue issue-number
1138 where @code{issue-number} is the number of the existing Rietveld
1141 @subsubheading Resetting git cl
1143 If @command{git cl} becomes confused, you can @qq{reset} it by
1151 @node Advanced Git procedures
1152 @section Advanced Git procedures
1155 @warning{This section is not necessary for normal contributors;
1156 these commands are presented for information for people interested
1157 in learning more about git.}
1159 It is possible to work with several branches on the same local Git
1160 repository; this is especially useful for translators who may have
1161 to deal with both @code{lilypond/translation} and a stable branch,
1162 e.g. @code{stable/2.12}.
1164 Some Git commands are introduced first, then a workflow with
1165 several Git branches of LilyPond source code is presented.
1169 * Advanced Git concepts::
1170 * Resolving conflicts::
1171 * Reverting all local changes::
1172 * Working with remote branches::
1174 * Applying remote patches::
1175 * Sending and receiving patches via email::
1180 @node Advanced Git concepts
1181 @subsection Advanced Git concepts
1184 A bit of Git vocabulary will be explained below. The following is
1185 only introductory; for a better understanding of Git concepts, you
1186 may wish to read @ref{Other Git documentation}.
1188 The @code{git@tie{}pull@tie{}origin} command above is just a
1189 shortcut for this command:
1192 git pull git://git.sv.gnu.org/lilypond.git/ @var{branch}:origin/@var{branch}
1196 where @code{@var{branch}} is typically @code{master} or
1197 @code{lilypond/translation}; if you do not know or remember, see
1198 @ref{Downloading remote branches} to remember which commands you
1199 issued or which source code you wanted to get.
1201 A @emph{commit} is a set of changes made to the sources; it also
1202 includes the committish of the parent commit, the name and e-mail
1203 of the @emph{author} (the person who wrote the changes), the name
1204 and e-mail of the @emph{committer} (the person who brings these
1205 changes into the Git repository), and a commit message.
1207 A @emph{committish} is the SHA1 checksum of a commit, a number
1208 made of 40 hexadecimal digits, which acts as the internal unique
1209 identifier for this commit. To refer to a particular revision,
1210 don't use vague references like the (approximative) date, simply
1211 copy and paste the committish.
1213 A @emph{branch} is nothing more than a pointer to a particular
1214 commit, which is called the @emph{head} of the branch; when
1215 referring to a branch, one often actually thinks about its head
1216 and the ancestor commits of the head.
1218 Now we will explain the two last commands you used to get the
1219 source code from Git---see @ref{Downloading individual branches}.
1222 git remote add -ft @var{branch} -m @var{branch} \
1223 origin git://git.sv.gnu.org/lilypond.git/
1225 git checkout -b @var{branch} origin/@var{branch}
1228 The @command{git@tie{}remote} has created a branch called
1229 @code{origin/@var{branch}} in your local Git repository. As this
1230 branch is a copy of the remote branch web from git.sv.gnu.org
1231 LilyPond repository, it is called a @emph{remote branch}, and is
1232 meant to track the changes on the branch from git.sv.gnu.org: it
1233 will be updated every time you run
1234 @command{git@tie{}pull@tie{}origin} or
1235 @command{git@tie{}fetch@tie{}origin}.
1237 The @command{git@tie{}checkout} command has created a branch named
1238 @code{@var{branch}}. At the beginning, this branch is identical
1239 to @code{origin/@var{branch}}, but it will differ as soon as you
1240 make changes, e.g. adding newly translated pages or editing some
1241 documentation or code source file. Whenever you pull, you merge
1242 the changes from @code{origin/@var{branch}} and
1243 @code{@var{branch}} since the last pulling. If you do not have
1244 push (i.e. @qq{write}) access on git.sv.gnu.org, your
1245 @code{@var{branch}} will always differ from
1246 @code{origin/@var{branch}}. In this case, remember that other
1247 people working like you with the remote branch @code{@var{branch}}
1248 of git://git.sv.gnu.org/lilypond.git/ (called
1249 @code{origin/@var{branch}} on your local repository) know nothing
1250 about your own @code{@var{branch}}: this means that whenever you
1251 use a committish or make a patch, others expect you to take the
1252 latest commit of @code{origin/@var{branch}} as a reference.
1254 Finally, please remember to read the man page of every Git command
1255 you will find in this manual in case you want to discover
1256 alternate methods or just understand how it works.
1259 @node Resolving conflicts
1260 @subsection Resolving conflicts
1263 Occasionally an update may result in conflicts -- this happens
1264 when you and somebody else have modified the same part of the same
1265 file and git cannot figure out how to merge the two versions
1266 together. When this happens, you must manually merge the two
1269 If you need some documentation to understand and resolve
1270 conflicts, see paragraphs @emph{How conflicts are presented} and
1271 @emph{How to resolve conflicts} in @command{git merge} man page.
1273 If all else fails, you can follow the instructions in
1274 @ref{Reverting all local changes}. Be aware that this eliminates
1275 any changes you have made!
1278 @node Reverting all local changes
1279 @subsection Reverting all local changes
1281 Sometimes git will become hopelessly confused, and you just want
1282 to get back to a known, stable state. This command destroys any
1283 local changes you have made, but at least you get back to the
1284 current online version:
1287 git reset --hard origin/master
1291 @node Working with remote branches
1292 @subsection Working with remote branches
1295 @subsubheading Fetching new branches from git.sv.gnu.org
1297 To fetch and check out a new branch named @code{@var{branch}} on
1298 git.sv.gnu.org, run from top of the Git repository
1301 git config --add remote.origin.fetch \
1302 +refs/heads/@var{branch}:refs/remotes/origin/@var{branch}
1304 git checkout --track -b @var{branch} origin/@var{branch}
1307 After this, you can pull @code{@var{branch}} from git.sv.gnu.org
1314 Note that this command generally fetches all branches you added
1315 with @command{git@tie{}remote@tie{}add} (when you initialized the
1316 repository) or @command{git@tie{}config@tie{}--add}, i.e. it
1317 updates all remote branches from remote @code{origin}, then it
1318 merges the remote branch tracked by the current branch into the
1319 current branch. For example, if your current branch is
1320 @code{master}, @code{origin/master} will be merged into
1324 @subsubheading Local clones, or having several working trees
1326 If you play with several Git branches, e.g. @code{master},
1327 @code{lilypond/translation}, @code{stable/2.12}), you may want to
1328 have one source and build tree for each branch; this is possible
1329 with subdirectories of your local Git repository, used as local
1330 cloned subrepositories. To create a local clone for the branch
1331 named @code{@var{branch}}, run
1334 git checkout @var{branch}
1335 git clone -lsn . @var{subdir}
1340 Note that @code{@var{subdir}} must be a directory name which does
1341 not already exist. In @code{@var{subdir}}, you can use all Git
1342 commands to browse revisions history, commit and uncommit changes;
1343 to update the cloned subrepository with changes made on the main
1344 repository, cd into @code{@var{subdir}} and run
1345 @command{git@tie{}pull}; to send changes made on the subrepository
1346 back to the main repository, run @command{git@tie{}push} from
1347 @code{@var{subdir}}. Note that only one branch (the currently
1348 checked out branch) is created in the subrepository by default; it
1349 is possible to have several branches in a subrepository and do
1350 usual operations (checkout, merge, create, delete...) on these
1351 branches, but this possibility is not detailed here.
1353 When you push @code{@var{branch}} from @code{@var{subdir}} to the
1354 main repository, and @code{@var{branch}} is checked out in the
1355 main repository, you must save uncommitted changes (see
1356 @command{git@tie{}stash}) and do
1357 @command{git@tie{}reset@tie{}--hard} in the main repository in
1358 order to apply pushed changes in the working tree of the main
1366 The commands above don't only bring you the latest version of the
1367 sources, but also the full history of revisions (revisions, also
1368 called commits, are changes made to the sources), stored in the
1369 @file{.git} directory. You can browse this history with
1372 git log # only shows the logs (author, committish and commit message)
1373 git log -p # also shows diffs
1374 gitk # shows history graphically
1377 @warning{The @code{gitk} command may require a separate
1378 @code{gitk} package, available in the appropriate distribution's
1382 @node Applying remote patches
1383 @subsection Applying remote patches
1386 TODO: Explain how to determine if a patch was created with
1387 @code{git@tie{}format-patch}.
1389 Well-formed git patches created with @code{git@tie{}format-patch}
1390 should be committed with the following command:
1396 Patches created without @code{git@tie{}format-patch} can be
1397 applied in two steps. The first step is to apply the patch to the
1401 git apply @var{patch}
1405 The second step is to commit the changes and give credit to the
1406 author of the patch. This can be done with the following command:
1409 git commit -a --author="@var{John Smith} <@var{john@@example.com}>"
1413 @node Sending and receiving patches via email
1414 @subsection Sending and receiving patches via email
1417 The default @code{x-diff} MIME type associated with patch files
1418 (i.e., files whose name ends in @code{.patch}) means that the
1419 encoding of line endings may be changed from UNIX to DOS format
1420 when they are sent as attachments. Attempting to apply such an
1421 inadvertently altered patch will cause git to fail with a message
1422 about @q{whitespace errors}.
1424 The solution to such problems is surprisingly simple---just change
1425 the default file extension of patches generated by git to end in
1426 @code{.txt}, for example:
1429 git config format.suffix '.patch.txt'
1432 This should cause email programs to apply the correct base64
1433 encoding to attached patches.
1435 If you receive a patch with DOS instead of UNIX line-endings, it
1436 can be converted back using the @code{dos2unix} utility.
1438 Lots of useful information on email complications with patches is
1439 provided on the Wine wiki at
1440 @uref{http://wiki.winehq.org/GitWine}.
1444 @subsection Commit access
1447 Most contributors are not able to commit patches directly to the
1448 main repository---only members of the LilyPond development team
1449 have @emph{commit access}. If you are a contributor and are
1450 interested in joining the development team, contact the Project
1451 Manager through the mailing list
1452 (@email{lilypond-devel@@gnu.org}). Generally, only contributors
1453 who have already provided a number of patches which have been
1454 pushed to the main repository will be considered for membership.
1456 If you have been approved by the Project Manager, use the
1457 following procedure to obtain commit access:
1461 If you don't already have one, set up a Savannah user account at
1462 @uref{https://savannah.gnu.org/account/register.php}. If your web
1463 browser responds with an @qq{untrusted connection} message when
1464 you visit the link, follow the steps for including the CAcert root
1465 certificate in your browser, given at
1466 @uref{http://savannah.gnu.org/tls/tutorial/}.
1470 After registering, if you are not logged in automatically, login
1471 at @uref{https://savannah.gnu.org/account/login.php}---this should
1472 take you to your @qq{my} page
1473 (@uref{https://savannah.gnu.org/my/}).
1477 Click on the @qq{My Groups} link to access the @qq{My Group
1478 Membership} page. From there, find the @qq{Request for Inclusion}
1479 box and search for @qq{LilyPond}. Among the search results, check
1480 the box labeled @qq{GNU LilyPond Music Typesetter} and write a
1481 brief (required) message for the Project Manager (@qq{Hey it's
1482 me!} should be fine).
1484 Note that you will not have commit access until the Project
1485 Manager activates your membership. Once your membership is
1486 activated, LilyPond should appear under the heading @qq{Groups I'm
1487 Contributor of} on your @qq{My Group Membership} page.
1491 Generate an SSH @q{dsa} key pair. Enter the following at the
1498 When prompted for a location to save the key, press <ENTER> to
1499 accept the default location (@file{~/.ssh/id_dsa}).
1501 Next you are asked to enter an optional passphrase. On most
1502 systems, if you use a passphrase, you will likely be prompted for
1503 it every time you use @command{git@tie{}push} or
1504 @command{git@tie{}pull}. You may prefer this since it can protect
1505 you from your own mistakes (like pushing when you mean to pull),
1506 though you may find it tedious to keep re-entering it.
1508 You can change/enable/disable your passphrase at any time with:
1511 ssh-keygen -f ~/.ssh/id_dsa -p
1514 Note that the GNOME desktop has a feature which stores your
1515 passphrase for you for an entire GNOME session. If you use a
1516 passphrase to @qq{protect you from yourself}, you will want to
1517 disable this feature, since you'll only be prompted once. Run the
1518 following command, then logout of GNOME and log back in:
1521 gconftool-2 --set -t bool \
1522 /apps/gnome-keyring/daemon-components/ssh false
1525 After setting up your passphrase, your private key is saved as
1526 @file{~/.ssh/id_dsa} and your public key is saved as
1527 @file{~/.ssh/id_dsa.pub}.
1531 Register your public SSH @q{dsa} key with Savannah. From the
1532 @qq{My Account Configuration} page, click on @qq{Edit SSH Keys},
1533 then paste the contents of your @file{~/.ssh/id_dsa.pub} file into
1534 one of the @qq{Authorized keys} text fields, and click
1537 Savannah should respond with something like:
1540 Success: Key #1 seen Keys registered
1545 Configure Git to use the SSH protocol (instead of the GIT
1546 protocol). From your local Git repository, enter:
1549 git config remote.origin.url \
1550 ssh://@var{user}@@git.sv.gnu.org/srv/git/lilypond.git
1554 where @var{user} is your username on Savannah.
1558 After your membership has been activated and you've configured Git
1559 to use SSH, test the connection with:
1565 SSH should issue the following warning:
1568 The authenticity of host 'git.sv.gnu.org (140.186.70.72)' can't
1570 RSA key fingerprint is
1571 80:5a:b0:0c:ec:93:66:29:49:7e:04:2b:fd:ba:2c:d5.
1572 Are you sure you want to continue connecting (yes/no)?
1575 Make sure the RSA key fingerprint displayed matches the one above.
1576 If it doesn't, respond @qq{no} and check that you configured Git
1577 properly in the previous step. If it does match, respond
1578 @qq{yes}. SSH should then issue another warning:
1581 Warning: Permanently added 'git.sv.gnu.org,140.186.70.72' (RSA) to
1582 the list of known hosts.
1585 The list of known hosts is stored in the file
1586 @file{~/.ssh/known_hosts}.
1588 At this point, you are prompted for your passphrase if you have
1589 one, then Git will attempt a pull.
1591 If @command{git@tie{}pull@tie{}--verbose} fails, you should see
1592 error messages like these:
1595 Permission denied (publickey).
1596 fatal: The remote end hung up unexpectedly
1599 If you get the above error, you may have made a mistake when
1600 registering your SSH key at Savannah. If the key is properly
1601 registered, you probably just need to wait for the Savannah server
1602 to activate it. It usually takes a few minutes for the key to be
1603 active after registering it, but if it still doesn't work after an
1604 hour, ask for help on the mailing list.
1606 If @command{git@tie{}pull@tie{}--verbose} succeeds, the output
1607 will include a @q{From} line that shows @q{ssh} as the protocol:
1610 From ssh://@var{user}@@git.sv.gnu.org/srv/git/lilypond
1613 If the protocol shown is not @q{ssh}, check that you configured
1614 Git properly in the previous step.
1618 Test your commit access with a dry run:
1621 git push --dry-run --verbose
1624 Note that recent versions of Git (Git 1.6.3 or later) will issue a
1625 big warning if the above command is used. The simplest solution
1626 is to tell Git to push all matching branches by default:
1629 git config push.default matching
1633 Then @code{git@tie{}push} should work as before. For more
1634 details, consult the @code{git@tie{}push} man page.
1638 @subsubheading Technical details
1642 On Firefox, to view or remove the CAcert root certificate, go to:
1643 Edit > Preferences > Advanced > Encryption > View Certificates >
1644 Authorities > Certificate Name > Root CA > CA Cert Signing
1648 The @command{git@tie{}config} commands above should modify your
1649 local repository's @file{.git/config} file. These lines:
1653 url = git://git.sv.gnu.org/lilypond.git/
1657 should now be changed to:
1661 url = ssh://@var{user}@@git.sv.gnu.org/srv/git/lilypond.git
1665 where @var{user} is your login name on Savannah.
1669 @command{git@tie{}config@tie{}push.default@tie{}matching} command
1670 should add these lines to @file{.git/config}:
1679 Encryption protocols, including ssh, generally do not permit packet
1680 fragmentation to avoid introducing a point of insecurity. This
1681 means that the maximum packet size must not exceed the smallest
1682 MTU (Maximum Transmission Unit) set in the routers along the path.
1683 This smallest MTU is determined by a procedure during call set-up
1684 which relies on the transmission over the path of ICMP packets.
1685 If any of the routers in the path block ICMP packets this mechanism
1686 fails, resulting in the possibility of packets being transmitted
1687 which exceed the MTU of one of the routers. If this happens the
1688 packet is discarded, causing the ssh session to hang, timeout or
1689 terminate with the error message
1692 ssh: connect to host <host ip addr> port 22: Bad file number
1693 fatal: The remote end hung up unexpectedly
1696 depending on precisely when in the proceedings the first large
1697 packet is transmitted. Most routers on the internet have MTU
1698 set to 1500, but routers installed in homes to connect via
1699 broadband may use a slightly smaller MTU for efficient transmission
1700 over ATM. If this problem is encountered a possible work-around is
1701 to set the MTU in the local router to 1500.
1703 @node Git on Windows
1704 @section Git on Windows
1706 @c Some of this may duplicate stuff in other sections
1707 @c But it is probably best for windows users to have it all together
1708 @c If necessary, clear this up later -td
1710 TODO: Decide what to do with this... Pare it down? Move
1711 paragraphs next to analogous Unix instructions? -mp
1713 @subsection Background to nomenclature
1715 Git is a system for tracking the changes made to source files by a
1716 distributed set of editors. It is designed to work without a
1717 master repository, but we have chosen to have a master repository
1718 for LilyPond files. Editors hold a local copy of the master
1719 repository together with any changes they have made locally.
1720 Local changes are held in a local @q{branch}, of which there may
1721 be several, but these instructions assume you are using just one.
1722 The files visible in the local repository always correspond to
1723 those on the currently @q{checked out} local branch.
1725 Files are edited on a local branch, and in that state the changes
1726 are said to be @q{unstaged}. When editing is complete, the
1727 changes are moved to being @q{staged for commit}, and finally the
1728 changes are @q{committed} to the local branch. Once committed,
1729 the changes (called a @q{commit}) are given a unique 40-digit
1730 hexadecimal reference number called the @q{Committish} or @q{SHA1
1731 ID} which identifies the commit to Git. Such committed changes
1732 can be sent to the master repository by @q{pushing} them (if you
1733 have write permission) or by sending them by email to someone who
1734 has, either as a complete file or as a @q{diff} or @q{patch}
1735 (which send just the differences from the master repository).
1737 @subsection Installing git
1740 @uref{http://code.google.com/p/msysgit/downloads/list} (note, not
1741 msysGit, which is for Git developers and not PortableGit, which is
1742 not a full git installation) and install it.
1744 Note that most users will not need to install SSH. That is not
1745 required until you have been granted direct push permissions to
1746 the master git repository.
1748 Start Git by clicking on the desktop icon. This will bring up a
1749 command line bash shell. This may be unfamiliar to Windows users.
1750 If so, follow these instructions carefully. Commands are entered
1751 at a $ prompt and are terminated by keying a newline.
1753 @subsection Initialising Git
1755 Decide where you wish to place your local Git repository, creating
1756 the folders in Windows as necessary. Here we call the folder to
1757 contain the repository @code{[path]/Git}, but if you intend using
1758 Git for other projects a directory name like @code{lilypond-git}
1759 might be better. You will need to have space for around
1762 Start the Git bash shell by clicking on the desk-top icon
1763 installed with Git and type
1769 to position the shell at your new Git repository.
1771 Note: if [path] contains folders with names containing spaces use
1783 to initialize your Git repository.
1785 Then type (all on one line; the shell will wrap automatically)
1788 git remote add -ft master origin git://git.sv.gnu.org/lilypond.git
1791 to download the lilypond master files.
1793 @warning{Be patient! Even on a broadband connection this can take
1794 10 minutes or more. Wait for lots of [new tag] messages and the $
1797 We now need to generate a local copy of the downloaded files in a
1798 new local branch. Your local branch needs to have a name. It is
1799 usual to call it @q{master} and we shall do that here.
1804 git checkout -b master origin/master
1807 This creates a second branch called @q{master}. You will see two
1808 warnings (ignore these), and a message advising you that your
1809 local branch @q{master} has been set up to track the remote
1810 branch. You now have two branches, a local branch called
1811 @q{master}, and a tracking branch called @q{origin/master}, which
1812 is a shortened form of @q{remotes/origin/master}.
1814 Return to Windows Explorer and look in your Git repository. You
1815 should see lots of folders. For example, the LilyPond
1816 documentation can be found in [path]/Git/Documentation/.
1818 The Git bash shell is terminated by typing @code{exit} or by
1819 clicking on the usual Windows close-window widget.
1823 Almost all subsequent work will use the Git Graphical User
1824 Interface, which avoids having to type command line commands. To
1825 start Git GUI first start the Git bash shell by clicking on the
1826 desktop icon, and type
1833 The Git GUI will open in a new window. It contains four panels
1834 and 7 pull-down menus. At this stage do not use any of the
1835 commands under Branch, Commit, Merge or Remote. These will be
1838 The top panel on the left contains the names of files which you
1839 are in the process of editing (Unstaged Changes), and the lower
1840 panel on the left contains the names of files you have finished
1841 editing and have staged ready for committing (Staged Changes). At
1842 present, these panels will be empty as you have not yet made any
1843 changes to any file. After a file has been edited and saved the
1844 top panel on the right will display the differences between the
1845 edited file selected in one of the panels on the left and the last
1846 version committed on the current branch.
1848 The panel at bottom right is used to enter a descriptive message
1849 about the change before committing it.
1851 The Git GUI is terminated by entering CNTL-Q while it is the
1852 active window or by clicking on the usual Windows close-window
1855 @subsection Personalising your local git repository
1857 Open the Git GUI, click on
1863 and enter your name and email address in the left-hand (Git
1864 Repository) panel. Leave everything else unchanged and save it.
1866 Note that Windows users must leave the default setting for line
1867 endings unchanged. All files in a git repository must have lines
1868 terminated by just a LF, as this is required for Merge to work,
1869 but Windows files are terminated by CRLF by default. The git
1870 default setting causes the line endings of files in a Windows git
1871 repository to be flipped automatically between LF and CRLF as
1872 required. This enables files to be edited by any Windows editor
1873 without causing problems in the git repository.
1875 @subsection Checking out a branch
1877 At this stage you have two branches in your local repository,
1878 both identical. To see them click on
1884 You should have one local branch called @q{master} and one
1885 tracking branch called @q{origin/master}. The latter is your
1886 local copy of the @q{remotes/origin/master} branch in the master
1887 LilyPond repository. The local @q{master} branch is where you
1888 will make your local changes.
1890 When a particular branch is selected, i.e., checked out, the files
1891 visible in your repository are changed to reflect the state of the
1892 files on that branch.
1894 @subsection Updating files from @q{remote/origin/master}
1896 Before starting the editing of a file, ensure your local
1897 repository contains the latest version of the files in the remote
1898 repository by first clicking
1901 Remote -> Fetch from -> origin
1907 This will place the latest version of every file, including all
1908 the changes made by others, into the @q{origin/master} branch of
1909 the tracking branches in your git repository. You can see these
1910 files by checking out this branch, but you must @emph{never} edit
1911 any files while this branch is checked out. Check out your local
1912 @q{master} branch again.
1914 You then need to merge these fetched files into your local
1915 @q{master} branch by clicking on
1918 Merge -> Local Merge
1922 and if necessary select the local @q{master} branch.
1924 Note that a merge cannot be completed if you have made any local
1925 changes which have not yet been committed.
1927 This merge will update all the files in the @q{master} branch to
1928 reflect the current state of the @q{origin/master} branch. If any
1929 of the changes conflict with changes you have made yourself
1930 recently you will be notified of the conflict (see below).
1932 @subsection Editing files
1934 First ensure your @q{master} branch is checked out, then simply
1935 edit the files in your local Git repository with your favourite
1936 editor and save them back there. If any file contains non-ASCII
1937 characters ensure you save it in UTF-8 format. Git will detect
1938 any changes whenever you restart Git GUI and the file names will
1939 then be listed in the Unstaged Changes panel. Or you can click
1940 the Rescan button to refresh the panel contents at any time. You
1941 may break off and resume editing any time.
1943 The changes you have made may be displayed in diff form in the top
1944 right-hand panel of Git GUI by clicking on the file name shown in
1945 one of the left panels.
1947 When your editing is complete, move the files from being Unstaged
1948 to Staged by clicking the document symbol to the left of each
1949 name. If you change your mind it can be moved back by clicking on
1950 the ticked box to the left of the name.
1952 Finally the changes you have made may be committed to your
1953 @q{master} branch by entering a brief message in the Commit
1954 Message box and clicking the Commit button.
1956 If you wish to amend your changes after a commit has been made,
1957 the original version and the changes you made in that commit may
1958 be recovered by selecting
1961 Commit -> Amend Last Commit
1965 or by checking the Amend Last Commit radio button at bottom right.
1966 This will return the changes to the Staged state, so further
1967 editing made be carried out within that commit. This must only be
1968 done @emph{before} the changes have been Pushed or sent to your
1969 mentor for Pushing - after that it is too late and corrections
1970 have to be made as a separate commit.
1973 @subsection Sending changes to @q{remotes/origin/master}
1975 If you do not have write access to @q{remotes/origin/master} you
1976 will need to send your changes by email to someone who does.
1978 First you need to create a diff or patch file containing your
1979 changes. To create this, the file must first be committed. Then
1980 terminate the Git GUI. In the git bash shell first cd to your Git
1987 if necessary, then produce the patch with
1990 git format-patch origin
1993 This will create a patch file for all the locally committed files
1994 which differ from @q{origin/master}. The patch file can be found
1995 in [path]/Git and will have a name formed from the commit message.
1997 @subsection Resolving merge conflicts
1999 As soon as you have committed a changed file your local
2000 @code{master} branch has diverged from @code{origin/master}, and
2001 will remain diverged until your changes have been committed in
2002 @code{remotes/origin/master} and Fetched back into your
2003 @code{origin/master} branch. Similarly, if a new commit has been
2004 made to @code{remotes/origin/master} by someone else and Fetched,
2005 your local @code{master} branch is divergent. You can detect a
2006 divergent branch by clicking on
2009 Repository -> Visualise all branch history
2012 This opens up a very useful new window called @q{gitk}. Use this
2013 to browse all the commits made by yourself and others.
2015 If the diagram at top left of the resulting window does not show
2016 your @code{master} tag on the same node as the
2017 @code{remotes/origin/master} tag your branch has diverged from
2018 @code{origin/master}. This is quite normal if files you have
2019 modified yourself have not yet been Pushed to
2020 @code{remotes/origin/master} and Fetched, or if files modified and
2021 committed by others have been Fetched since you last Merged
2022 @code{origin/master} into your local @code{master} branch.
2024 If a file being merged from @code{origin/master} differs from one
2025 you have modified in a way that cannot be resolved automatically
2026 by git, Merge will report a Conflict which you must resolve by
2027 editing the file to create the version you wish to keep.
2029 This could happen if the person updating
2030 @code{remotes/origin/master} for you has added some changes of his
2031 own before committing your changes to
2032 @code{remotes/origin/master}, or if someone else has changed the
2033 same file since you last fetched the file from
2034 @code{remotes/origin/master}.
2036 Open the file in your editor and look for sections which are
2039 [to be completed when I next have a merge conflict to be sure I
2040 give the right instructions -td]
2043 @subsection Other actions
2045 The instructions above describe the simplest way of using git on
2046 Windows. Other git facilities which may usefully supplement these
2050 @item Using multiple local branches (Create, Rename, Delete)
2051 @item Resetting branches
2052 @item Cherry-picking commits
2053 @item Pushing commits to @w{remote/origin/master}
2054 @item Using gitk to review history
2057 Once familiarity with using git on Windows has been gained the
2058 standard git manuals can be used to learn about these.
2061 @node Repository directory structure
2062 @section Repository directory structure
2065 @c TODO: integrate the roadmap better
2066 @verbatiminclude ROADMAP
2069 @node Other Git documentation
2070 @section Other Git documentation
2074 Official git man pages:
2075 @uref{http://www.kernel.org/pub/software/scm/git/docs/}
2078 More in-depth tutorials: @uref{http://git-scm.com/documentation}
2081 Book about git: @uref{http://progit.org/,Pro Git}