On Tue, Dec 4, 2018 at 8:22 AM Duy Nguyen <pclouds@xxxxxxxxx> wrote:
>
> Thanks for all the comments! There are still some I haven't replied
> (either I'll agree and do it anyway, or I'll need some more time to
> digest)
>
> On Tue, Dec 4, 2018 at 1:45 AM Elijah Newren <newren@xxxxxxxxx> wrote:
> > > +'git restore-files' [--from=<tree-ish>] <pathspec>...
> >
> > Isn't this already inferred by the previous line? Or was the
> > inclusion of --from on the previous line in error? Looking at the
> > git-checkout manpage, it looks like you may have just been copying an
> > existing weirdness, but it needs to be fixed. ;-)
>
> Hehe.
>
> > > +'git restore-files' (-p|--patch) [--from=<tree-ish>] [<pathspec>...]
> > > +
> > > +DESCRIPTION
> > > +-----------
> > > +Updates files in the working tree to match the version in the index
> > > +or the specified tree.
> > > +
> > > +'git restore-files' [--from=<tree-ish>] <pathspec>...::
> >
> > <tree-ish> and <pathspec>? I understand <commit-ish> and <pathspec>,
> > or <tree-ish> but have no clue why it'd be okay to specify <tree-ish>
> > and <pathspec> together. What does that even mean?
> >
> > Also, rather than fixing from <tree-ish> to <commit-ish> or <commit>,
> > perhaps we should just use <revision> here? (I'm thinking of git
> > rev-parse's "Specifying revisions", which suggests "revisions" as a
> > good substitute for "commit-ish" that isn't quite so weird for new
> > users.)
>
> tree-ish is technically more accurate. But I'm ok with just
> <revision>. If you give it a blob oid then you should get a nice
> explanation what you're doing wrong anyway.
Documenting as <revision> but having it be more general under the hood
and actually accept <tree-ish> sounds good to me. I just think the
pain of trying to explain <tree-ish> is too much of a hurdle for
users, especially as I expect it to be very unlikely that users will
ever take advantage of it.
> > > + Overwrite paths in the working tree by replacing with the
> > > + contents in the index or in the <tree-ish> (most often a
> > > + commit). When a <tree-ish> is given, the paths that
> > > + match the <pathspec> are updated both in the index and in
> > > + the working tree.
> >
> > Is that the default we really want for this command? Why do we
> > automatically assume these files are ready for commit? I understand
> > that it's what checkout did, but I'd find it more natural to only
> > affect the working tree by default. We can give it an option for
> > affecting the index instead (or perhaps in addition).
>
> Yeah, that behavior of updating the index always bothers me when I use
> it but I seemed to forget when working on this.
>
> > > +--ours::
> > > +--theirs::
> > > + Check out stage #2 ('ours') or #3 ('theirs') for unmerged
> > > + paths.
> > > ++
> > > +Note that during `git rebase` and `git pull --rebase`, 'ours' and
> > > +'theirs' may appear swapped; `--ours` gives the version from the
> > > +branch the changes are rebased onto, while `--theirs` gives the
> > > +version from the branch that holds your work that is being rebased.
> > > ++
> > > +This is because `rebase` is used in a workflow that treats the
> > > +history at the remote as the shared canonical one, and treats the
> > > +work done on the branch you are rebasing as the third-party work to
> > > +be integrated, and you are temporarily assuming the role of the
> > > +keeper of the canonical history during the rebase. As the keeper of
> > > +the canonical history, you need to view the history from the remote
> > > +as `ours` (i.e. "our shared canonical history"), while what you did
> > > +on your side branch as `theirs` (i.e. "one contributor's work on top
> > > +of it").
> >
> > Total aside because I'm not sure what you could change here, but man
> > do I hate this.
>
> Uh it's actually documented? I'm always confused by this too. --ours
> and --theirs at this point are pretty much tied to stage 2 and 3.
> Nothing I can do about it. But if you could come up with some other
> option names, then we could make "new ours" to be stage 3 during
> rebase, for example.
I don't think it's a naming issue, personally. Years ago we could
have defined --ours and --theirs differently based on which kind of
operation we were in the middle of, but you are probably right that
they are now tied to stage 2 and 3. But there's another place that we
might still be able to address this; I think the brain-damage here may
have just been due to the fact that the recursive merge machinery was
rather inflexible and required HEAD to be stage 2. If it were a
little more flexible, then we might just be able to make this problem
go away. Maybe it can still be fixed (I haven't dug too deeply into
it), but if so, the only fix needed here would be to remove this long
explanation about why the tool gets things totally backward.
> > > +Part of the linkgit:git[1] suite
> >
> >
> > My single biggest worry about this whole series is that I'm worried
> > you're perpetuating and even further ingraining one of the biggest
> > usability problems with checkout: people suggest and use it for
> > reverting/restoring paths to a previous version, but it doesn't do
> > that:
> >
> > git restore-files --from master~10 Documentation/
> > <edit some non-documentation files>
> > git add -u
> > git commit -m "Rationale for changing files including reverting Documentation/"
> >
> > In particular, now you have a mixture of files in Documentation/ from
> > master~10 (er, now likely master~11) and HEAD~1; any files and
> > sub-directories that existed in HEAD~1 still remain and are mixed with
> > all other files in Documentation/ from the older commit.
> >
> > You may think this is a special case, but this particular issue
> > results in some pretty bad surprises. Also, it was pretty surprising
> > to me just how difficult it was to implement an svn-like revert in
> > EasyGit, in large part because of this 'oversight' in git. git
> > checkout -- <paths> to me has always been fundamentally wrong, but I
> > just wasn't sure if I wanted to fight the backward compatibility
> > battle and suggest changing it. With a new command, we definitely
> > shouldn't be reinforcing this error. (And maybe we should consider
> > taking the time to fix git checkout too.)
>
> What would be the right behavior for
>
> git restore-files --from=master~10 Documentation/
>
> then? Consider it an error? I often use "git checkout HEAD" and "git
> checkout HEAD^" (usually with -p) but not very far back like
> master~10.
Well, when you use a file rather than a directory:
git restore-files --from=master~10 foo.c
then you expect
git diff master~10 foo.c
to come back empty afterward. I expect the same if I give a directory
rather than a file. (Even if it does make 'restore-files' feel
slightly mis-named.)
> > > +If the branch exists in multiple remotes and one of them is named by
> > > +the `checkout.defaultRemote` configuration variable, we'll use that
> > > +one for the purposes of disambiguation, even if the `<branch>` isn't
> > > +unique across all remotes. Set it to
> > > +e.g. `checkout.defaultRemote=origin` to always checkout remote
> > > +branches from there if `<branch>` is ambiguous but exists on the
> > > +'origin' remote. See also `checkout.defaultRemote` in
> > > +linkgit:git-config[1].
> >
> > So switch-branch will be controlled by checkout.* config variables?
> > That probably makes the most sense, but it does dilute the advantage
> > of adding these simpler commands.
> >
> > Also, the fact that we're trying to make a simpler command makes me
> > think that removing the auto-vivify behavior from the default and
> > adding a simple flag which users can pass to request will allow this
> > part of the documentation to be hidden behind the appropriate flag,
> > which may make it easier for users to compartmentalize the command and
> > it's options, enabling them to learn as they go.
>
> Sounds good. I don't know a good name for this new option though so
> unless anybody comes up with some suggestion, I'll just disable
> checkout.defaultRemote in switch-branch. If it comes back as a new
> option, it can always be added later.
>
> > > +'git switch-branch' -c|-C <new_branch> [<start_point>]::
> > > +
> > > + Specifying `-c` causes a new branch to be created as if
> > > + linkgit:git-branch[1] were called and then switched to. In
> > > + this case you can use the `--track` or `--no-track` options,
> > > + which will be passed to 'git branch'. As a convenience,
> > > + `--track` without `-c` implies branch creation; see the
> > > + description of `--track` below.
> >
> > Can we get rid of --track/--no-track and just provide a flag (which
> > takes no arguments) for the user to use? Problems with --track:
> > * it's not even in your synopsis
> > * user has to repeat themselves (e.g. 'next' in two places from '-c
> > next --track origin/next'); this repetition is BOTH laborious AND
> > error-prone
> > * it's rather inconsistent: --track is the default due to
> > auto-vivify when the user specifies nothing but a branch name that
> > doesn't exist yet, but when the user realizes the branch doesn't exist
> > yet and asks to have it created then suddenly tracking is not the
> > default??
>
> I don't think --track is default anymore (maybe I haven't updated the
> man page correctly). The dwim behavior is only activated in
> switch-branch when you specify --guess to reduce the amount of magic
> we throw at the user. With that in mind, do we still hide
> --track/--no-track from switch-branch?
Ooh, you're adding --guess? Cool, that addresses my concerns, just in
a different manner.
Personally, I'd leave --track/--no-track out. It's extra mental
overhead, git branch has options for setting those if they need some
special non-default setup, and if there is enough demand for it we can
add it later. Removing options once published is much harder.
> > I'm not sure what's best, but here's some food for thought:
> >
> >
> > git switch-branch <branch>
> > switches to <branch>, if it exists. Error cases:
> > * If <branch> isn't actually a branch but a <tag> or
> > <remote-tracking-branch> or <revision>, error out and suggest using
> > --detach.
> > * If <branch> isn't actually a branch but there is a similarly named
> > <remote-tracking-branch> (e.g. origin/<branch>), then suggest using
> > -c.
>
> I would make these advice so I can hide them. Or if I manage to make
> all these hints one line then I'll make it unconditional.
>
> > git switch-branch -c <branch>
> > creates <branch> and, if a relevant-remote-tracking branch exists,
> > base the branch on that revision and set the new branch up to track
>
> Hmm.. this is a bit magical and could be surprising. If I create (and
> switch to) a new branch foo, I don't necessarily mean tracking
> origin/foo (I may not even think about origin/foo when I type the
> command). So tentatively no.
Yeah, if you're adding --guess then I'm happy. I do think, though,
that if the user runs switch-branch to a branch that doesn't exist, we
should check if there is an associated remote-tracking branch so that
we can provide a better error message and help users learn about
--guess. (Also, will there be a short -g form?)
>
> > > +If `-C` is given, <new_branch> is created if it doesn't exist;
> > > +otherwise, it is reset. This is the transactional equivalent of
> > > ++
> > > +------------
> > > +$ git branch -f <branch> [<start_point>]
> > > +$ git switch-branch <branch>
> > > +------------
> > > ++
> > > +that is to say, the branch is not reset/created unless "git
> > > +switch-branch" is successful.
> >
> > ...and when exactly would it fail? Reading this, it looks like the
> > only possible error condition was removed due saying we'll reset the
> > branch if it already exists, so it's rather confusing.
>
> Yeah probably just scrape it. The atomic nature is not worth highlighting.
>
>
> > > +'git switch-branch' --detach [<commit>]::
> > > +
> > > + Prepare to work on a unnamed branch on top of <commit> (see
> > > + "DETACHED HEAD" section), and updating the index and the files
> > > + in the working tree. Local modifications to the files in the
> > > + working tree are kept, so that the resulting working tree will
> > > + be the state recorded in the commit plus the local
> > > + modifications.
> > > ++
> > > +When the <commit> argument is a branch name, the `--detach` option can
> > > +be used to detach HEAD at the tip of the branch (`git switch-branch
> > > +<branch>` would check out that branch without detaching HEAD).
> > > ++
> > > +Omitting <commit> detaches HEAD at the tip of the current branch.
> > > +
> > > +OPTIONS
> > > +-------
> > > +-q::
> > > +--quiet::
> > > + Quiet, suppress feedback messages.
> > > +
> > > +--[no-]progress::
> > > + Progress status is reported on the standard error stream
> > > + by default when it is attached to a terminal, unless `--quiet`
> > > + is specified. This flag enables progress reporting even if not
> > > + attached to a terminal, regardless of `--quiet`.
> > > +
> > > +-f::
> > > +--force::
> > > + Proceed even if the index or the working tree differs from
> > > + HEAD. This is used to throw away local changes.
> >
> > Haven't thought through this thoroughly, but do we really need an
> > option for that instead of telling users to 'git reset --hard HEAD'
> > before switching branches if they want their stuff thrown away?
>
> For me it's just a bit more convenient. Hit an error when switching
> branch? Recall the command from bash history, stick -f in it and run.
> Elsewhere I think both Junio and Thomas (or maybe only Junio) suggests
> moving the "git reset" functionality without moving HEAD to one of
> these commands, which goes the opposite direction...
Fair enough.
> > > +-c <new_branch>::
> > > +--create <new_branch>::
> > > + Create a new branch named <new_branch> and start it at
> > > + <start_point>; see linkgit:git-branch[1] for details.
> > > +
> > > +-C <new_branch>::
> > > +--force-create <new_branch>::
> > > + Creates the branch <new_branch> and start it at <start_point>;
> > > + if it already exists, then reset it to <start_point>. This is
> > > + equivalent to running "git branch" with "-f"; see
> > > + linkgit:git-branch[1] for details.
> >
> > Makes sense, but let's get the -b/-B vs. -c/-C consistent.
>
> Another option I'm considering is -n/-N (for _new_ branch). Maybe
> -c/-C is good enough.
Actually, -n/-N seems like a good idea, especially since --guess also
creates a branch. If we do stick with -c/-C, then we may need to
document --guess as implying -c to avoid confusion (and then make sure
we get the synopsis correct to show which flags can be used together).
> > > +-l::
> > > + Create the new branch's reflog; see linkgit:git-branch[1] for
> > > + details.
> >
> > ?? Jettison this.
>
> Yep. It looks weird to me too. reflog is just behind the scene these
> days. Nobody need to explicitly ask for reflog anymore.
>
> > > +--orphan <new_branch>::
> > > + Create a new 'orphan' branch, named <new_branch>, started from
> > > + <start_point> and switch to it. The first commit made on this
> >
> > What?? started from <start_point>? The whole point of --orphan is
> > you have no parent, i.e. no start point. Also, why does the
> > explanation reference an argument that wasn't in the immediately
> > preceding synopsis?
>
> I guess bad phrasing. It should be "switch to <start_point> first,
> then prepare the worktree so that the first commit will have no
> parent". Or something along that line.
>
> You should really review git-checkout.txt btw ;-)
I did after writing several of these comments, and yeah, it really
needs a clean up. Seems like something someone would do when writing
a (partial) replacement or simplified alternative. ;-)
To be fair though, I suspect anyone familiar enough with git that
looks at git-checkout.txt again is probably going to miss at least one
thing that is bad for new users no matter how closely they look, just
because they've grown accustomed to the documentation as it is. I was
trying to help point out possible issues that I spotted, but I suspect
others may be able to point out more.
> > > + new branch will have no parents and it will be the root of a new
> > > + history totally disconnected from all the other branches and
> > > + commits.
> > > ++
> > > +The index and the working tree are adjusted as if you had previously run
> > > +"git checkout <start_point>". This allows you to start a new history
> > > +that records a set of paths similar to <start_point> by easily running
> > > +"git commit -a" to make the root commit.
> > > ++
> > > +This can be useful when you want to publish the tree from a commit
> > > +without exposing its full history. You might want to do this to publish
> > > +an open source branch of a project whose current tree is "clean", but
> > > +whose full history contains proprietary or otherwise encumbered bits of
> > > +code.
> > > ++
> > > +If you want to start a disconnected history that records a set of paths
> > > +that is totally different from the one of <start_point>, then you should
> > > +clear the index and the working tree right after creating the orphan
> > > +branch by running "git rm -rf ." from the top level of the working tree.
> > > +Afterwards you will be ready to prepare your new files, repopulating the
> > > +working tree, by copying them from elsewhere, extracting a tarball, etc.
> >
> > Ick. Seems overly complex. I'd rather that --orphan defaulted to
> > clearing the index and working tree, and that one would need to pass
> > HEAD for <start_point> if you wanted to start out with all those other
> > files. That would certainly make the explanation a little clearer to
> > users, and more natural when they start experimenting with it.
> >
> > However, --orphan is pretty special case. Do we perhaps want to leave
> > it out of this new command and only include it in checkout?
>
> I started this by simply splitting git-checkout in two commands that,
> combined, can do everything git-checkout can. Then suggestions to have
> better default came in and I think we started to drift further to
> _removing_ options and falling back to git-checkout.
>
> I think we could still keep "complicated" options as long as they are
> clearly described and don't surprise users until they figure them out.
> That way I don't have to go back to git-checkout and deal with all the
> ambiguation it creates.
Fair enough...though I think it may make sense to also review the
complicated options and determine if they are overly complicated. I
think --orphan qualifies (I stumbled with it a bit for years the
occasional time I needed to use it), and my small suggestion above
would simplify both it and its description. We should probably also
consider just removing <start_point> as an acceptable argument to
--orphan; if people want files from some revision after creating an
orphan branch that's a simple extra command.
> > > +-m::
> > > +--merge::
> > > + If you have local modifications to one or more files that are
> > > + different between the current branch and the branch to which
> > > + you are switching, the command refuses to switch branches in
> > > + order to preserve your modifications in context. However,
> > > + with this option, a three-way merge between the current
> > > + branch, your working tree contents, and the new branch is
> > > + done, and you will be on the new branch.
> > > ++
> > > +When a merge conflict happens, the index entries for conflicting
> > > +paths are left unmerged, and you need to resolve the conflicts
> > > +and mark the resolved paths with `git add` (or `git rm` if the merge
> > > +should result in deletion of the path).
> > > +
> > > +--conflict=<style>::
> > > + The same as --merge option above, but changes the way the
> > > + conflicting hunks are presented, overriding the
> > > + merge.conflictStyle configuration variable. Possible values are
> > > + "merge" (default) and "diff3" (in addition to what is shown by
> > > + "merge" style, shows the original contents).
> > > +
> > > +--ignore-other-worktrees::
> > > + `git switch-branch` refuses when the wanted ref is already
> > > + checked out by another worktree. This option makes it check
> > > + the ref out anyway. In other words, the ref can be held by
> > > + more than one worktree.
> >
> > seems rather dangerous...is the goal to be an easier-to-use suggestion
> > for new users while checkout continues to exist, or is this command
> > meant to handle all branch switching functionality that checkout has?
>
> As explained above. I'm still thinking the latter, but with fewer
> surprises and confusion. Though I guess I could be convinced to go
> with the former (the problem with the former is, even as a
> no-longer-new user, I still find git-checkout not that pleasant to use
> and want a better replacement)
>
> > > +<branch>::
> > > + Branch to checkout; if it refers to a branch (i.e., a name that,
> > > + when prepended with "refs/heads/", is a valid ref), then that
> > > + branch is checked out. Otherwise, if it refers to a valid
> > > + commit, your HEAD becomes "detached" and you are no longer on
> > > + any branch (see below for details).
> >
> > I thought we requiring --detach in order to detach. Does this
> > paragraph need updating? Also, if we require --detach when we'll be
> > detaching HEAD, then this paragraph gets a LOT simpler.
>
> Yep. I really need to read through the document and update all of it.
>
> > > +You can use the `"@{-N}"` syntax to refer to the N-th last
> > > +branch/commit checked out using "git checkout" operation. You may
> > > +also specify `-` which is synonymous to `"@{-1}`.
> > > ++
> > > +As a special case, you may use `"A...B"` as a shortcut for the
> > > +merge base of `A` and `B` if there is exactly one merge base. You can
> > > +leave out at most one of `A` and `B`, in which case it defaults to `HEAD`.
> >
> > I actually didn't know about the A...B special case for checkout.
> > Interesting...but I'm starting to wonder if this is too much info for
> > a "simplified command".
>
> I could just hint about A...B and send the user to git-checkout.txt if
> they need to know more. They can learn about git-checkout that way
> too.
It may be fine to stay. Lots of my comments were just "let's try to
note any weirdness or complication that might seem excessive so we at
least have a conversation about it" (because it's easy to gloss over
since we've looked at these documents so many times) rather than a
"this definitely needs to go".
