From: Phillip Wood Date: Wed, 23 Sep 2020 18:23:20 GMT Subject: Re: [PATCH 3/3] commit: add an option the reword HEAD Message-ID: <41dcb8cb-8e43-04ce-2ddd-d69c765ee327@gmail.com> In-Reply-To: Hi Dscho On 23/09/2020 11:22, Johannes Schindelin wrote: > Hi Phillip, > > On Mon, 21 Sep 2020, Phillip Wood via GitGitGadget wrote: > >> From: Phillip Wood >> >> If one notices a typo in the last commit after starting to stage >> changes for the next commit it is useful to be able to reword the last >> commit without changing its contents. Currently the way to do that is >> by specifying --amend --only with no pathspec which is not that >> obvious to new users (so much so that before beb635ca9c ("commit: >> remove 'Clever' message for --only --amend", 2016-12-09) commit >> printed a message to congratulate the user on figuring out how to do >> it). If the last commit is empty one has to pass --allow-empty as well >> even though the contents are not being changed. This commits adds a >> --reword option for commit that rewords the last commit without >> changing its contents. > > I would like to explain the idea I tried to get across when I proposed to > implement support for `reword!` (and `--reword`) because I feel that it > will change the design of this patch in a rather big way. > > First of all, let me explain the scenario in which I long for the > `--reword` option: I maintain several patch thickets, the most obvious one > being Git for Windows' patch thicket that is merge-rebased [*1*] onto > every new Git version. > > At times, I need to adjust a commit message in that patch thicket. It > would be quite wasteful to perform a full merge-rebase, therefore I > typically call `git commit --squash -c `, copy the > oneline, paste it after the `squash!` line (surrounded by empty lines), and > then reword the commit message. When the next Git version comes out, I do > a merging-rebase, and when the editor pops up because of that `squash!` > oneline, I remove the now-obsolete version(s) of the commit message. > > Obviously, I have to be careful to either also pass `--only` (which I > somehow managed to learn about only today) or I have to make sure that I > have no staged changes. In practice, I actually specify a bogus path, > which has the same effect as `--only`. > > What I would actually rather have is the `--reword` option: `git commit > --reword `. In my mind, this would _add_ a new, "empty" commit, > letting me edit the commit message of the specified commit, and using that > as commit message, prefixed with the line `reword! `. > > This, in turn, would need to be accompanied by support in the interactive > rebase, to perform the desired reword (which is admittedly quite a bit > different from what the way the todo command `reword` works). > > With that in mind, I would like to caution against the design of your > current patch, because it would slam the door shut on the way I would like > `--reword` to work. I'm keen to have an easy way to reword HEAD and a way to implement your reword! idea. I posted a comment on your gitgitgadget issue about reword! and drop![1] pointing to some patches[2] that implement the reword! idea as amend!. I think we want to be able to fixup a commit and reword it at the same time which is way I chose the name amend! rather than reword! The implementation currently changes `git commit --amend` to take an optional commit which isn't ideal. I wonder if calling it revise! would be better then we could have `git commit --reword` to reword HEAD and `git commit --revise ` to create a commit that will reword and fixup when the user runs `git rebase -i --autostash`. fold! is another possibility. I don't think this patch series stops us implementing something for rebase but it would mean we couldn't use the name reword! unless we allow `git commit --reword` to take an optional commit which I'm not that keen on. What do you think to an alternative name? Best Wishes Phillip [1] https://github.com/gitgitgadget/git/issues/259 [2] https://github.com/phillipwood/git/commits/wip/rebase-amend > Ciao, > Dscho > > Footnote *1*: In Git for Windows, I want to not only rebase the patches > (so that they are as ready to be submitted to the Git mailing list as they > can be) but I also want the commit history to fast-forward. The strategy I > settled on is the "merging rebase": it is a rebase that starts with a fake > merge of the previous commit history, i.e. merging it in using `-s ours` > so that only the commit history comes in, but not the changes. This allows > contributors to pull without problems, but also provides the benefits of > having a rebased version of the patches. The price is a rather big commit > history on top of Git's main branch, as Git for Windows' main branch > contains not only the newest iteration of its patches, but _all_ > iterations (at least since the first merging-rebase). >