I'm trying to grasp the Mercurial basics so please bear with me. :) My current workflow is as follows:
do some work until I'm ready to commit or need the others' changes
pull
at this point I'd like to merge my work with the latest changesets and commit, however Mercurial insists on me committing before merging
so it goes like "commit, merge, commit" and I'm basically committing everything twice, writing the same notes in both changesets and pushing two changesets at a time
Is it intended to be so? Is it possible to have just one changeset coming from me with every merge? Is it indeed desirable?
I've read a lot of online manuals but still feel I do not have solid understanding of the process. All comments are welcome. Thanks!
EDIT: Turns out I didn't know that update could merge incoming changes with uncommitted edits.
Merging always creates a separate changeset in Mercurial.
Plus, merging is not possible as long as you have uncommitted stuff in your local repository.
So the solution is to commit first, and pull and merge afterwards.
This will always result in two changesets, not one.
(...because merging always creates a separate changeset)
But you don't commit the same stuff twice, and especially you shouldn't write the same commit message twice:
The first commit is what you actually changed ("fixed a bug in the foo bar").
The second commit is just the merge (TortoiseHG actually pre-populates the commit message with "Merge", 99% of the time I just leave it like that).
This workflow will prevent a merge in the history, but you still do a merge as noted below:
Do some work until you are ready to commit or need another's changes.
hg pull
hg update (Note: hg pull -u does this and the previous in one step.
During hg update, your uncommitted changes will be merged with the new tip of your current branch. You will still have to resolve any conflicts.
hg commit when ready.
I still recommend if you have extensive changes to commit first before pulling/merging because it is easier to start over by updating to that changeset if the merge goes badly.
Keeping the hg pull and hg update separate allows you to look at the incoming changesets and predict how the merge will go.
The reason is feels strange is that you delay your commit until you want to integrate with the others.
A big feature of distributed version control is that commits are local. Because they're local you should commit often — commit every time you have a small consistent chunk of work done. Your commits are not inflicted on others immediately so you wont interrupt them by making many small commits.
If you begin making more commits you'll see that your workflow becomes:
$ hg commit -m "Refactoring for Issue123"
$ hg commit -m "Basic functionality for Issue123"
$ hg commit -m "Fixed off-by-one error (Issue123)"
$ hg commit -m "Finished implementing Issue123"
$ hg commit -m "Added more tests for Issue123"
$ hg commit -m "Begin use new function from Issue123"
$ hg pull
$ hg merge
$ hg commit -m "Merge"
Here the ratio of merge commits to "real" commits is much more sensible.
Many people (myself included) like to use the rebase extension to avoid the merge completely. That extension linearizes the commits by faking the history so that it looks like you did your four commits after the changesets you pulled down with hg pull. The only change in workflow is that you hg rebase instead of hg merge above and then skip the final commit.
Related
I know that when you update to a previous revision, you create a new branch on your next commit. What happens when you clone an earlier revision? Will your next commit (or push) create a new branch?
The reason I ask is because our Tip is currently broken, so until it gets fixed, I was planning to do the following:
hg clone -r <prev_rev> <Tip>
# make changes
hg commit -m "my changes" -u me
# wait for Tip to get fixed
hg pull
hg merge
hg push
Will this work? Or will it end up creating a new branch or a dangling head? I would like to avoid doing either of these things.
Yes, that will create a branch, at least in the sense of having a "fork" in the history of the repository.
The branch will not be assigned a new branch name, but that in itself is not usually important in terms of understanding what the history will look like in a repository.
If your original repo was:
A-B-C-D
Then you do a hg clone -r C... and a new commit, you will end up with:
A-B-C-(D)
\
E
Now, since you have cloned only up to C, that specific local repository may not include D yet. But when you eventually synchronize it with another that will have to be dealt with. If you PULL, then you will get D in that clone. If you try to push HG will warn you about creating a new remote head for which the usual approach is to merge.
There is nothing wrong with this approach. If you need to work around an issue in tip for the time being, this is a reasonable way to do it. But you don't really need a new clone, you could just hg update C and work from there, which might be easier.
I have some uncommitted changes C in my repo. I would like remember that changes in any way and get clean code (without that changes), make a little change and commit it. Now, I would like to recover my changes C and continue working on it. I know that I can deal with it using a lot of ways, but that ways are irritating. How to do it using mercurial?
So, to be more precise I need something like a stack:
Working on the code. Remember changes C on the stack.
hg update --clean
Make a change C2. Commit it.
Pop from stack a changeset C and work on it. But, now the repositorium contains committed change C2 and uncommitted C. It may cause that I need to merge but I expect that this merge will be invisible from the point of view repositorium.
While you certainly can work with mercurial queues, there's IMHO an easier and nicer way: change your default phase to secret and work with those commits like normal commits. Commits in phase secret are mutable and will not be exposed by push and pull commands acting on the repo.
This process has the advantage that you do not need to change your workflow - whether you work with commits you want to share (phase draft or public), or whether you still consider them work-in-progress and keep them locally only.
Additionally if you enable the evolve extension, you gain several benefits: it becomes even easier to amend commits and evolve (thus rebase) all child commits which depend on it.
The big advantage over the use of the mercurial queues is that you can make full use of the inbuild merge features - thus if the underlaying code changes, rebasing the new changesets is WAY easier and natural than using queues and hg shelve.
See the introduction to hg phases and changeset evolution which needs the evolve extension.
Enable the Mercurial Queues extension in your mercurial.ini or .hgrc file:
[extensions]
mq =
Then you can,
hg qnew save # save work in progress as a temporary commit
hg qpop # remove that commit
Make some more changes....
hg ci -m "new changes"
hg qpush # push the saved commit back.
hg qfinish -a # convert all temp commits to full commits.
You can also enable the shelve extension:
[extensions]
shelve =
Then you can:
hg shelve # "put away" current uncommitted changes.
*do other work*
hg unshelve # bring the shelved changes back
See hg help mq and hg help shelve for more info.
I've tried shelve, mq as described in other answers but to be honest I generally stick with:
hg diff > saved.patch # This assumes you've not aliased diff to a UI!!!
hg update -C
.. work
hg patch -f --no-commit saved.patch # I alias this for less typing
.. continue
Less book-keeping involved, its never gone wrong unlike shelve, and the patch itself is more easily portable. Just use common-sense and either make sure the patch applies fully, or use the --partial option and manually complete the patch.
I cloned a project to my local directory and made a lot of changes. My current goal is to push my changed code to a new branch in the remote repository. And eventually this new branch will be merged back to default.
My problem is, because of some stupid effort in the past a few weeks to try to recover some missing files, I end up with a few branch names that I don't want being shown in public.
Here's what I have:
$hg branches
dev-v02 197:xxxxx
dev2 194:xxxxx
dev 183:xxxxx
qa 189:xxxxx
$hg branch
dev-v02
My question is, if I push my current branch dev-v02 to the remote repository by "hg push --new-branch", and this branch later get merged back to default, will the unwanted branches show up in history of default? And if so, is there a safe way to purge them?
I do NOT want to discard my changes. I just don't want the unwanted branches showing up in "hg branches" or "hg his" commands by whoever later clones the project from the remote repository. I searched online and found "hg strip" but I couldn't tell from the article if it would also remove the changes I've made. Thanks.
Edit: I just cloned my local repository by "hg clone -r 197 original-dir dest-dir" as suggested by both kevin and chessbot and now hg branches shows:
dev-02 192:xxxxx
qa 187:xxxxx (inactive)
I guess "qa" remains because I had pushed it to the remote as a QA branch and closed it later, and I just have to live with that. I will push from this new directory from now on. Thanks guys for your help.
Try hg push --new-branch -b dev-v02 to specify that you're pushing only that branch.
(See: https://www.mercurial-scm.org/repo/hg/help/push)
Another thing you could do: Clone the repository locally on your machine, strip out the branches you don't want, and then push that clone to the server. Then you retain your history locally without pushing it to everyone else.
It depends.
Branches are permanently associated with a commit. The branch is part of the commit, and contributes to the hash. Changing the branch of a commit in the past would alter all commit hashes from that point forward. This is quite different from Git, where a branch is little more than an ephemeral pointer to a HEAD. Such pointers are implemented in Mercurial as bookmarks.
If the unwanted branches appear on commits which are (ancestors of) commits you want to publish, there is very little you can do, short of recreating the history with all-new hashes. This could (for instance) be done with hg export and hg import, along with local cloning and (probably) a certain amount of shell scripting. More efficiently, you could use the convert extension to automate the process. Since this changes commit hashes, it will likely cause serious problems if any of the commits have already been distributed publicly.
If you have no interest in sharing the offending commits, you can simply not publish them. This can be done with selective pushing. However, since you'll always have to manually exclude those commits every time you push, it's probably safer to clone and strip (or clone selectively with the -r flag). You can then push from your partial clone with impunity. Assuming you have a sufficiently recent version of Mercurial, you can also force the commits into the secret phase, so that they will not be pushed:
hg phase -fs revisions
You don't want to use hg strip, because it permanently removes the commits from the history (see Editing History in the Mercurial wiki)
If I were you, I would close the branches instead:
hg up -C badbranch
hg commit --close-branch -m 'close badbranch, this approach never worked'
hg up -C default
(source: Pruning branches in the Mercurial wiki)
After closing a branch, hg branches doesn't show it anymore.
If you do want to see closed branches, use the -c parameter:
hg branches -c
Disadvantage:
hg his still shows closed branches.
You could use the -b parameter though, to show only the default branch:
hg his -b default
Is there a way to edit a commit message in Mercurial on a commit after other commits have occured using TortoiseHg? I've read these posts:
How to edit incorrect commit message in Mercurial?
Mercurial: how to amend the last commit?
and have been able to update a "regular" commit message when it is the latest commit on a branch (using TortoiseHg). However, I haven't been able to figure out how to edit a commit message when other commits have occurred after the one I want to edit. It always edits the last commit.
Based on Ed Cottrell's comment, I did a test where I made two commits without pushing to the central repo, and I still have the same issue - only the last commit message can be edited.
EDIT: I should clarify that I am looking to update a changeset that has been pushed.
Histedit extension (bundled with TortoiseHG now) has a mess command for changing the commit message of historical changesets.
Unfortunately, this command is not supported by the TortoiseHG GUI so you need to run the command from command line.
As long as the change in question is local and hasn't been pushed anywhere, it is possible.
The commit message is used to compute the globally unique hash id that is used for all repositories to determine whether or not they already have a changeset. If you change the commit message, you change the unique hash id and every repo will see it as a "new" changeset. All other repositories that had the old changeset will try to get the new one and ask that you merge it with itself.... This is not a good thing, so the short answer to your question is "don't do it".
If you could definitively purge that change from all other repos, so that only the local copy is left you could essentially get to the "draft" state. Note that if any repo has the "old" changeset, it will be pushed to the central repo someday and cause the mess that we are trying to avoid.
If the changeset is still local (e.g. in draft status), you can use hg commit --amend if it is the parent of the working directory.
If there are changes after it, I would use mq and hg qimport all the changes down to and including the one where you want to edit the commit message. hg qpop -a and then hg qpush to get to the patch that represents the changeset you want to edit. Then hg qrefresh -e and make your changes. Then just hg qfin -a and you should be good to go.
The advice from Edward is good — if you've pushed your changes to another repository, you should consider them set in stone and not update the commit message or any other aspect of them.
However, we're working on changing this in Mercurial. There is an experimental extension that will allow you to do more extensive history editing and push those edits to other repositories. It is called the Evolve Extension and it enables some behavior that is partly in the core of Mercurial and partly outside core.
When using evolve, you can edit the second-to-last commit message like this
$ hg update .^
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
$ hg commit --amend -m 'new commit message'
1 new unstable changesets
$ hg stabilize
more:[5] old tip changeset
atop:[6] new commit message
The extension allows you to do this as long as the changesets are in the draft phase. To keep them in the draft phase after pushing them somewhere, the repository you push to need to be configured as a non-publishing repository. You can read more about this in the Changeset Evolution Documentation.
How do I view commits that are about to be pushed?
I'd made a local commit. Pull a change. And no it requires a merge.
I prefer not to merge and would like to undo the commit,
Pull,
Update changes,
Then commit again.
How do I do it since rollback only undo the last command which is pull?
That's really the way Mercurial works, and you shouldnt fight it in the name of a straight linear history, but there are tools that can edit history. Enable the rebase extension and just run hg rebase after your pull. It will move your local commit to the tip automatically in the simple case you described.
How do I view commits that are about to be pushed?
Use hg outgoing. That shows what hg push would have sent to the server. The opposite command is hg incoming, which shows what hg pull would have retrieved.
I'd made a local commit. Pull a change. And no it requires a merge. I prefer not to merge and would like to undo the commit, Pull, Update changes, Then commit again.
Like Mark says, you're looking for the rebase extension. Enable it with
[extensions]
rebase =
in your config file and then run
$ hg pull
$ hg rebase
to move your local work (this can be multiple changesets, not just a single as in your work around!) on top of the changesets you just pulled down.
How do I do it since rollback only undo the last command which is pull?
Please don't use hg rollback as a general undo mechanism. It's a low-level command that should not be used as much as it is, especially not by new users. The rollback command removes the last transaction from the repository — a transaction in Mercurial is typically the last changeset you made or the last changesets (plural) you pulled into the repository.