Submitting patches
------------------

short story:

git aliases
~~~~~~~~~~~
$ git config --global sendemail.aliasesfile ~/.git_aliases
$ git config --global sendemail.aliasfiletype mutt
$ echo "alias abrt-ml crash-catcher@lists.fedorahosted.org" >> ~/.git_aliases

what to do when push rejects
~~~~~~~~~~~~~~~~~~~~~~~~~~~~
whenever you see after $ git push origin HEAD rejection with message that
you are going non-fast forward. don't panic. it's super easy to fix it
without any *stupid* merge commit from server after $ git pull

version 1
$ git pull --rebase

version 2
$ git format-patch -X     # where X is commits you are ahead of master
$ git reset --hard HEAD~X # where X is commits you are ahead of master
$ git am -3s 000*

version 3
$ git branch <new-feature>
$ git reset --hard HEAD~X # where X is commits you are ahead of master
$ git pull
$ git merge <new-feature>


there are zillion other way how to do this. golden rule is, clean
everything from master, pull and than merge/apply your chenges.


working in master branch
~~~~~~~~~~~~~~~~~~~~~~~~
edit
edit
edit

[master u=]  $ git diff --check
[master u=]  $ git add <files>
[master u+1] $ git commit -s

edit
edit
edit

[master u+1] $ git diff --check
[master u+1] $ git add <files>
[master u+2] $ git commit -s

save your commits to local branch
[master u+2] $ git branch <new-feature>

[master u=] $ git reset --hard HEAD~X # where X is commits you are ahead of master

do review before submitting patches
[master u=] $ git show master..<new-feature>

send patches
[master u=] $ git send-email --to=abrt-ml master..<new-feature>

push patches
[master u=]  $ git pull
[master u=]  $ git merge --no-ff <new-feature> # w/o --no-ff git will
                                               # create [master u+2] w/o
					       # merge commit
[master u+3] $ git push origin HEAD



long story:

(1) Make separate commits for logically separate changes.

Unless your patch is really trivial, you should not be sending
out a patch that was generated between your working tree and
your commit head.  Instead, always make a commit with complete
commit message and generate a series of patches from your
repository.  It is a good discipline.

Give an explanation for the change(s) that is detailed enough so
that people can judge if it is good thing to do, without reading
the actual patch text to determine how well the code does what
the explanation promises to do.

If your description starts to get too long, that's a sign that you
probably need to split up your commit to finer grained pieces.
That being said, patches which plainly describe the things that
help reviewers check the patch, and future maintainers understand
the code, are the most beautiful patches.  Descriptions that summarise
the point in the subject well, and describe the motivation for the
change, the approach taken by the change, and if relevant how this
differs substantially from the prior version, are all good things
to have.

Oh, another thing.  I am picky about whitespaces.  Make sure your
changes do not trigger errors with the sample pre-commit hook shipped
in templates/hooks--pre-commit.  To help ensure this does not happen,
run git diff --check on your changes before you commit.


(1a) Try to be nice to C compilers

NULL pointers shall be written as NULL, not as 0.



(2) Generate your patch using git tools out of your commits.

git based diff tools generate unidiff which is the preferred format.

You do not have to be afraid to use -M option to "git diff" or
"git format-patch", if your patch involves file renames.  The
receiving end can handle them just fine.

Please make sure your patch does not include any extra files
which do not belong in a patch submission.  Make sure to review
your patch after generating it, to ensure accuracy.  Before
sending out, please make sure it cleanly applies to the "master"
branch head.



(3) Sending your patches.

People on the abrt/libreport mailing list need to be able to read and
comment on the changes you are submitting.  It is important for
a developer to be able to "quote" your changes, using standard
e-mail tools, so that they may comment on specific portions of
your code.  For this reason, all patches should be submitted
"inline".  WARNING: Be wary of your MUAs word-wrap
corrupting your patch.  Do not cut-n-paste your patch; you can
lose tabs that way if you are not careful.

It is a common convention to prefix your subject line with
[PATCH].  This lets people easily distinguish patches from other
e-mail discussions.  Use of additional markers after PATCH and
the closing bracket to mark the nature of the patch is also
encouraged.  E.g. [PATCH/RFC] is often used when the patch is
not ready to be applied but it is for discussion, [PATCH v2],
[PATCH v3] etc. are often seen when you are sending an update to
what you have previously sent.

"git format-patch" command follows the best current practice to
format the body of an e-mail message.  At the beginning of the
patch should come your commit message, ending with the
Signed-off-by: lines, and a line that consists of three dashes,
followed by the diffstat information and the patch itself. If
you are forwarding a patch from somebody else, optionally, at
the beginning of the e-mail message just before the commit
message starts, you can put a "From: " line to name that person.

You often want to add additional explanation about the patch,
other than the commit message itself.  Place such "cover letter"
material between the three dash lines and the diffstat.

Do not attach the patch as a MIME attachment, compressed or not.
Do not let your e-mail client send quoted-printable.  Do not let
your e-mail client send format=flowed which would destroy
whitespaces in your patches. Many
popular e-mail applications will not always transmit a MIME
attachment as plain text, making it impossible to comment on
your code.  A MIME attachment also takes a bit more time to
process.  This does not decrease the likelihood of your
MIME-attached change being accepted, but it makes it more likely
that it will be postponed.

Exception:  If your mailer is mangling patches then someone may ask
you to re-send them using MIME, that is OK.

Do not PGP sign your patch, at least for now.  Most likely, your
maintainer or other people on the list would not have your PGP
key and would not bother obtaining it anyway.  Your patch is not
judged by who you are; a good patch from an unknown origin has a
far better chance of being accepted than a patch from a known,
respected origin that is done poorly or does incorrect things.

If you really really really really want to do a PGP signed
patch, format it as "multipart/signed", not a text/plain message
that starts with '-----BEGIN PGP SIGNED MESSAGE-----'.  That is
not a text/plain, it's something else.



(4) Sign your work

To improve tracking of who did what, we've borrowed the
"sign-off" procedure from the Linux kernel project on patches
that are being emailed around.  Although core abrt/libreport
is a lot smaller project it is a good discipline to follow it.

The sign-off is a simple line at the end of the explanation for
the patch, which certifies that you wrote it or otherwise have
the right to pass it on as a open-source patch.  The rules are
pretty simple: if you can certify the below:

        Developer's Certificate of Origin 1.1

        By making a contribution to this project, I certify that:

        (a) The contribution was created in whole or in part by me and I
            have the right to submit it under the open source license
            indicated in the file; or

        (b) The contribution is based upon previous work that, to the best
            of my knowledge, is covered under an appropriate open source
            license and I have the right under that license to submit that
            work with modifications, whether created in whole or in part
            by me, under the same open source license (unless I am
            permitted to submit under a different license), as indicated
            in the file; or

        (c) The contribution was provided directly to me by some other
            person who certified (a), (b) or (c) and I have not modified
            it.

        (d) I understand and agree that this project and the contribution
            are public and that a record of the contribution (including all
            personal information I submit with it, including my sign-off) is
            maintained indefinitely and may be redistributed consistent with
            this project or the open source license(s) involved.

then you just add a line saying

        Signed-off-by: Random J Developer <random@developer.example.org>

This line can be automatically added by git if you run the git-commit
command with the -s option.

Notice that you can place your own Signed-off-by: line when
forwarding somebody else's patch with the above rules for
D-C-O.  Indeed you are encouraged to do so.  Do not forget to
place an in-body "From: " line at the beginning to properly attribute
the change to its true author (see (2) above).

Also notice that a real name is used in the Signed-off-by: line. Please
don't hide your real name.

If you like, you can put extra tags at the end:

1. "Reported-by:" is used to credit someone who found the bug that
   the patch attempts to fix.
2. "Acked-by:" says that the person who is more familiar with the area
   the patch attempts to modify liked the patch.
3. "Reviewed-by:", unlike the other tags, can only be offered by the
   reviewer and means that she is completely satisfied that the patch
   is ready for application.  It is usually offered only after a
   detailed review.
4. "Tested-by:" is used to indicate that the person applied the patch
   and found it to have the desired effect.

You can also create your own tag or use one that's in common usage
such as "Thanks-to:", "Based-on-patch-by:", or "Mentored-by:".

------------------------------------------------
An ideal patch flow

Here is an ideal patch flow for this project the current maintainer
suggests to the contributors:

 (0) You come up with an itch.  You code it up.

 (1) Send it to the list and cc people who may need to know about
     the change.

     The people who may need to know are the ones whose code you
     are butchering.  These people happen to be the ones who are
     most likely to be knowledgeable enough to help you, but
     they have no obligation to help you (i.e. you ask for help,
     don't demand).  "git log -p -- $area_you_are_modifying" would
     help you find out who they are.

 (2) You get comments and suggestions for improvements.  You may
     even get them in a "on top of your change" patch form.

 (3) Polish, refine, and re-send to the list and the people who
     spend their time to improve your patch.  Go back to step (2).

 (4) The list forms consensus that the last round of your patch is
     good.  Send it to the list and cc the maintainer.

------------------------------------------------
Know the status of your patch after submission

* You can use Git itself to find out when your patch is merged in
  master. 'git pull --rebase' will automatically skip already-applied
  patches, and will let you know. This works only if you rebase on top
  of the branch in which your patch has been merged


