path: root/docs/CONTRIBUTE

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                        When Contributing Source Code

 This document is intended to offer guidelines that can be useful to keep in
 mind when you decide to contribute to the project. This concerns new features
 as well as corrections to existing flaws or bugs.

 1. Learning cURL
 1.1 Join the Community
 1.2 License
 1.3 What To Read

 2. Write a good patch
 2.1 Follow code style
 2.2 Non-clobbering All Over
 2.3 Write Separate Patches
 2.4 Patch Against Recent Sources
 2.5 Document
 2.6 Test Cases

 3. Sharing Your Changes
 3.1 How to get your changes into the main sources
 3.2 About pull requests
 3.3 Making quality patches
 3.5 Write good commit messages
 3.6 Write Access to git Repository
 3.7 How To Make a Patch with git
 3.8 How To Make a Patch without git

==============================================================================

1. Learning cURL

1.1 Join the Community

 Skip over to https://curl.haxx.se/mail/ and join the appropriate mailing
 list(s).  Read up on details before you post questions. Read this file before
 you start sending patches! We prefer patches and discussions being held on
 the mailing list(s), not sent to individuals.

 Before posting to one of the curl mailing lists, please read up on the mailing
 list etiquette: https://curl.haxx.se/mail/etiquette.html

 We also hang out on IRC in #curl on irc.freenode.net

 If you're at all interested in the code side of things, consider clicking
 'watch' on the curl repo at github to get notified on pull requests and new
 issues posted there.

1.2. License

 When contributing with code, you agree to put your changes and new code under
 the same license curl and libcurl is already using unless stated and agreed
 otherwise.

 If you add a larger piece of code, you can opt to make that file or set of
 files to use a different license as long as they don't enforce any changes to
 the rest of the package and they make sense. Such "separate parts" can not be
 GPL licensed (as we don't want copyleft to affect users of libcurl) but they
 must use "GPL compatible" licenses (as we want to allow users to use libcurl
 properly in GPL licensed environments).

 When changing existing source code, you do not alter the copyright of the
 original file(s). The copyright will still be owned by the original
 creator(s) or those who have been assigned copyright by the original
 author(s).

 By submitting a patch to the curl project, you are assumed to have the right
 to the code and to be allowed by your employer or whatever to hand over that
 patch/code to us. We will credit you for your changes as far as possible, to
 give credit but also to keep a trace back to who made what changes. Please
 always provide us with your full real name when contributing!

1.3 What To Read

 Source code, the man pages, the INTERNALS document, TODO, KNOWN_BUGS and the
 most recent changes in the git log. Just lurking on the curl-library mailing
 list is gonna give you a lot of insights on what's going on right now. Asking
 there is a good idea too.

2. Write a good patch

2.1 Follow code style

 When writing C code, follow the CODE_STYLE already established in the
 project. Consistent style makes code easier to read and mistakes less likely
 to happen. Run 'make checksrc' before you submit anything, to make sure you
 follow the basic style. That script doesn't verify everything, but if it
 complains you know you have work to do.

2.2 Non-clobbering All Over

 When you write new functionality or fix bugs, it is important that you don't
 fiddle all over the source files and functions. Remember that it is likely
 that other people have done changes in the same source files as you have and
 possibly even in the same functions. If you bring completely new
 functionality, try writing it in a new source file. If you fix bugs, try to
 fix one bug at a time and send them as separate patches.

2.3 Write Separate Patches

 It is annoying when you get a huge patch from someone that is said to fix 511
 odd problems, but discussions and opinions don't agree with 510 of them - or
 509 of them were already fixed in a different way. Then the patcher needs to
 extract the single interesting patch from somewhere within the huge pile of
 source, and that gives a lot of extra work. Preferably, all fixes that
 correct different problems should be in their own patch with an attached
 description exactly what they correct so that all patches can be selectively
 applied by the maintainer or other interested parties.

 Also, separate patches enable bisecting much better when we track problems in
 the future.

2.4 Patch Against Recent Sources

 Please try to get the latest available sources to make your patches
 against. It makes the life of the developers so much easier. The very best is
 if you get the most up-to-date sources from the git repository, but the
 latest release archive is quite OK as well!

2.5 Document

 Writing docs is dead boring and one of the big problems with many open source
 projects. Someone's gotta do it. It makes it a lot easier if you submit a
 small description of your fix or your new features with every contribution so
 that it can be swiftly added to the package documentation.

 The documentation is always made in man pages (nroff formatted) or plain
 ASCII files. All HTML files on the web site and in the release archives are
 generated from the nroff/ASCII versions.

2.6 Test Cases

 Since the introduction of the test suite, we can quickly verify that the main
 features are working as they're supposed to. To maintain this situation and
 improve it, all new features and functions that are added need to be tested
 in the test suite. Every feature that is added should get at least one valid
 test case that verifies that it works as documented. If every submitter also
 posts a few test cases, it won't end up as a heavy burden on a single person!

 If you don't have test cases or perhaps you have done something that is very
 hard to write tests for, do explain exactly how you have otherwise tested and
 verified your changes.

3. Sharing Your Changes

3.1 How to get your changes into the main sources

 Ideally you file a pull request on github, but you can also send your plain
 patch to the curl-library mailing list.

 Either way, your change will be reviewed and discussed there and you will be
 expected to correct flaws pointed out and update accordingly, or the change
 risk stalling and eventually just get deleted without action. As a submitter
 of a change, you are the owner of that change until it has been merged.

 Respond on the list or on github about the change and answer questions and/or
 fix nits/flaws. This is very important. We will take lack of replies as a
 sign that you're not very anxious to get your patch accepted and we tend to
 simply drop such changes.

3.2 About pull requests

 With github it is easy to send a pull request to the curl project to have
 changes merged this way instead of mailing patches to the curl-library
 mailing list. See https://github.com/curl/curl/pulls

 We prefer pull requests as it makes it a proper git commit that is easy to
 merge and they are easy to track and not that easy to loose in a flood of
 many emails, like they sometimes do on the mailing lists.

 When you ajust your pull requests after review, consider squashing the
 commits so that we can review the full updated version more easily.

3.3 Making quality patches

 Make the patch against as recent sources as possible.

 If you've followed the tips in this document and your patch still hasn't been
 incorporated or responded to after some weeks, consider resubmitting it to
 the list or better yet: change it to a pull request.

3.5 Write good commit messages

 A short guide to how to do fine commit messages in the curl project.

      ---- start ----
      [area]: [short line describing the main effect]

      [separate the above single line from the rest with an empty line]

      [full description, no wider than 72 columns that describe as much as
      possible as to why this change is made, and possibly what things
      it fixes and everything else that is related]

      [Bug: link to source of the report or more related discussion]
      [Reported-by: John Doe - credit the reporter]
      [whatever-else-by: credit all helpers, finders, doers]
      ---- stop ----

 Don't forget to use commit --author="" if you commit someone else's work,
 and make sure that you have your own user and email setup correctly in git
 before you commit

3.6 Write Access to git Repository

 If you are a very frequent contributor, you may be given push access to the
 git repository and then you'll be able to push your changes straight into the
 git repo instead of sending changes as pull requests or by mail as patches.

 Just ask if this is what you'd want. You will be required to have posted
 several high quality patches first, before you can be granted push access.

3.7 How To Make a Patch with git

 You need to first checkout the repository:

     git clone https://github.com/curl/curl.git

 You then proceed and edit all the files you like and you commit them to your
 local repository:

     git commit [file]

 As usual, group your commits so that you commit all changes that at once that
 constitutes a logical change. See also section "3.5 Write good commit
 messages".

 Once you have done all your commits and you're happy with what you see, you
 can make patches out of your changes that are suitable for mailing:

     git format-patch remotes/origin/master

 This creates files in your local directory named NNNN-[name].patch for each
 commit.

 Now send those patches off to the curl-library list. You can of course opt to
 do that with the 'git send-email' command.

3.8 How To Make a Patch without git

 Keep a copy of the unmodified curl sources. Make your changes in a separate
 source tree. When you think you have something that you want to offer the
 curl community, use GNU diff to generate patches.

 If you have modified a single file, try something like:

     diff -u unmodified-file.c my-changed-one.c > my-fixes.diff

 If you have modified several files, possibly in different directories, you
 can use diff recursively:

     diff -ur curl-original-dir curl-modified-sources-dir > my-fixes.diff

 The GNU diff and GNU patch tools exist for virtually all platforms, including
 all kinds of Unixes and Windows:

 For unix-like operating systems:

     https://savannah.gnu.org/projects/patch/
     https://www.gnu.org/software/diffutils/

 For Windows:

     http://gnuwin32.sourceforge.net/packages/patch.htm
     http://gnuwin32.sourceforge.net/packages/diffutils.htm