threads / discuss / 52779

Develop a patch series with git?

Subject: Develop a patch series with git?

## tl;dr

4 messages between Feb 11, 2020 and Feb 12, 2020.

replies: 3people: 4as markdown or json

Steve Keller· Feb 11, 2020, 09:22 UTC · lore

I wonder how git supports developing a series of small patches. In my usual development I go back and forth along a series of patches before I can commit them all. I use quilt for that.

Say I want to add feature FOO and start a patch "FOO" editing some source file. In the process of doing so I realize that I need an extension of some function to base my patch on, so I do "quilt pop" to undo patch FOO and insert a new patch BAR and then re-apply FOO by calling quilt push. No I can use the new extension from BAR in my current patch FOO. The patch series often contains quite a number of patches and I push, pop, and edit these patches quite often. Only when everything is done I use git commit all the patches into the repository.

My question is whether there is git functionality to replace quilt. Or is the combination of quilt and git common?

Steve

Shourya Shukla· Feb 11, 2020, 13:40 UTC · re: Steve Keller · lore

Re: Develop a patch series with git?

Hello Steve,

> My question is whether there is git functionality to replace quilt.
> Or is the combination of quilt and git common?

I think we can use interactive rebase[1] as well as 'git am'[2] (am = apply mail) to apply a series of patches from a mailbox.

In the case of, let's say a dependency missing on your end, you can do an interactive rebase using 'git rebase -i' to edit your _mini-commits_ which you will be making on applying the patches to include the dependencies. One can also 'squash' commits together(i.e. meld multiple commits into one) in case you want a smaller commit history or you think there is a redundancy in any of your commits.

BTW, I think that 'git quiltimport' is quite old now right? And maybe even obsolete?

Best, Shourya Shukla

[1]: https://git-scm.com/book/en/v2/Git-Tools-Rewriting-History [2]: https://git-scm.com/docs/git-am

Jeff King· Feb 11, 2020, 20:00 UTC · re: Steve Keller · lore

Re: Develop a patch series with git?

On Tue, Feb 11, 2020 at 10:22:20AM +0100, Steve Keller wrote:

Show 16 quoted lines

> I wonder how git supports developing a series of small patches.  In my
> usual development I go back and forth along a series of patches before
> I can commit them all.  I use quilt for that.
> 
> Say I want to add feature FOO and start a patch "FOO" editing some
> source file.  In the process of doing so I realize that I need an
> extension of some function to base my patch on, so I do "quilt pop" to
> undo patch FOO and insert a new patch BAR and then re-apply FOO by
> calling quilt push.  No I can use the new extension from BAR in my
> current patch FOO.  The patch series often contains quite a number of
> patches and I push, pop, and edit these patches quite often.  Only
> when everything is done I use git commit all the patches into the
> repository.
> 
> My question is whether there is git functionality to replace quilt.
> Or is the combination of quilt and git common?

Another responder mentioned "rebase -i", which is the most direct equivalent. But on a smaller scale, also look at "git add -p", which lets you selectively stage hunks for commit.

So quite often my flow is something like:

  1. Messy writing and refactoring, while I get a handle on what my
     changes are going to be.

  2. "git add -p" to pull out some hunks related to refactoring, then
     "git commit" to give it a rough commit message.

  3. Repeat step 2 (with maybe some more step 1 in between) as necessary
     until you have a sequence of rough patches.

  4. Revisit each patch individually with "rebase -i", possibly
     re-ordering, fixing bugs, fleshing out commit messages, etc.
     Another useful tool here is:

       git rebase -x "make test"

     which makes sure that the intermediate steps are all correct.

-Peff

Johannes Schindelin· Feb 12, 2020, 09:02 UTC · re: Jeff King · lore

Re: Develop a patch series with git?

Hi,

On Tue, 11 Feb 2020, Jeff King wrote:

Show 21 quoted lines

> On Tue, Feb 11, 2020 at 10:22:20AM +0100, Steve Keller wrote:
>
> > I wonder how git supports developing a series of small patches.  In my
> > usual development I go back and forth along a series of patches before
> > I can commit them all.  I use quilt for that.
> >
> > Say I want to add feature FOO and start a patch "FOO" editing some
> > source file.  In the process of doing so I realize that I need an
> > extension of some function to base my patch on, so I do "quilt pop" to
> > undo patch FOO and insert a new patch BAR and then re-apply FOO by
> > calling quilt push.  No I can use the new extension from BAR in my
> > current patch FOO.  The patch series often contains quite a number of
> > patches and I push, pop, and edit these patches quite often.  Only
> > when everything is done I use git commit all the patches into the
> > repository.
> >
> > My question is whether there is git functionality to replace quilt.
> > Or is the combination of quilt and git common?
>
> Another responder mentioned "rebase -i", which is the most direct
> equivalent.

I think the most direct equivalent is `guilt`: https://repo.or.cz/w/guilt.git

There haven't been any patches since May 2018 which either means that the project is dead or that it is so robust that no changes are necessary anymore.

Ciao, Johannes