Discard a local branch in Mercurial before it is pushed - mercurial

Many times it happens that I have few commits on my local Hg repository which I don't want to push and sometimes I want to remove the local branch altogether. But I cannot rollback more than one commit which leaves me no choice than creating a new clone and download the whole repository again. This feels stupid, since if I could just delete my local branch which has not affected the remote repository in anyway, then I wouldn't have to create and setup a new clone. So, is it how it is in Mercurial or is there some way to discard a local branch?
Thanks!

If you enable the mq extension (bundled with Mercurial), you can use hg strip. Be careful, though, as this will modify the history of your repository. The safe method is to clone your repository up to the revision preceding the creation of the branch you want to discard, then to pull the remaining changesets that you want to keep.

I know its too late but it may be useful for any one:
If your branch is not pushed yet.
First rollback changes hg rollback only if you have done commit but
not yet pushed
Second run hg update --clean
Third run hg branch any-existing-branch
Fourth run hg pull -u

If you find yourself doing this often perhaps you should be using bookmarks instead of named branches. http://stevelosh.com/blog/2009/08/a-guide-to-branching-in-mercurial/

Related

Safe way to purge history - Mercurial

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

View/undo a Hg commit?

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.

creating a new branch in mercurial: "abort: push creates new remote head"

I am trying to do something very simple: create a new branch. But I messed up. Where did I make the mistake, and how do I fix it?
I am the only user of Mercurial. I had revision 54 committed and pushed to remote repository. I wanted to create a branch based on revision 53, so I updated my local copy to revision 53, made changes, and committed (ignoring the warning about "it's not the head"). Then when I am trying to push to remote repository, it says
abort: push creates new remote head
Maybe I needed to tell Mercurial that I want to create a new branch? If so, how and at what point?
Thanks!
You tell Mercurial that it can go ahead with
$ hg push --force
You need to force it since multiple (unnamed) heads are normally discouraged. The problem with them is that people that clone the repository wont know which one to use. But since you're the only user you can just go ahead and push.
The alternative is to use a named branch (with hg branch) and then you'll use
$ hg push --new-branch
to allow the creation of a new branch on the remote. Named branches have the advantage that they make it easy to distinguish the two branches. They have the disadvantage that they are permanent. Permanent means that you cannot remove the branch name from the changesets on the branch — the name is literally baked directly into the changeset.
Bookmarks provide a way to have non-permanent branch names, see hg help bookmarks.
Another reason for this error: probably there are some UNMERGED changes form the central repo in your default branch.
hg up default
hg merge
hg ci -m "Merge"
hg pus
I did this. Using TortoiseHg ... this is how I fixed it:
In settings, I enabled the Strip extension then right clicked the branch i did not want, Modified History - strip. If you have pushed, then it needs to be stripped from all other repositories, including workmates who have pulled your unwanted branch.
An alternative is to merge the unwanted branch into your main branch, but do not take any of the changes from that branch - I am unsure of how that mechanism works.

How do you delete a commit in Mercurial?

I want to completely delete a Mercurial commit as if it was never entered in the repository and move back to my prior commit.
Is this possible?
If it was your last commit and you haven't pushed it anywhere, you can do that with rollback. Otherwise, no. Not really. Time to change your passwords.
Edit: It has been pointed out that you can clone from an older revision and merge in the changes you want to keep. That's also true, unless you have pushed it to a repo you don't control. Once you push, your data is very likely to be very hard to get back.
You can try to remove mq info about your commit.
For this you need to go File->Settings->Extensions.
There check mq and restart gui.
After that just right click on unneeded commit and
ModifyHistory->Strip
To edit the history I would use the Histedit Extension extension.
hg histedit 45:c3a3a271d11c
However keep in mind this only makes sense in a situation where you have not yet pushed the commits to the public repository, you own the public repository and/or you can account for all the clones out there. If you receive the following error:
abort: can't rebase immutable changeset 43ab8134e7af
It means that Mecurial thinks this is a public changeset (see phases) that has already been pushed - you can force it to be a draft again doing:
hg phase -f -d 45:c3a3a271d11c
I encounter this fairly often. I make a commit and then pull to push. But then there is something incoming that makes my newly made commit unnecessary. A plain hg rollback isn't enough because it only undoes the pull...
This is the thing to do:
hg strip <rev>
Things are painless when you don't push your changesets anywhere.
If it's more than one commit and/or you already pushed it somewhere else, you can clone your repository and specify the last changeset that should be cloned.
See my answer here how to do this:
Mercurial: Fix a borked history
If you only committed locally and didn't push, you can just create a clone locally (as described in my link) and you're done.
If you already pushed to some remote repository, you would have to replace that with your clone.
Of course it depends if you are able (or allowed) to do this.
You can use "hg backout" to do a reverse merge basically. All options are discussed in the freely available book "Mercurial: The Definitive Guide":
http://hgbook.red-bean.com/read/finding-and-fixing-mistakes.html
If using tortoise you can use modify history > strip...
Yes. Unless I am mistaken, as of v2.3 (rel. 2012/08/01) you can use the HisteditExtension with a drop command to drop a commit, along with strip or backout to remove changes.
A simple Google search on the feature: https://www.google.com/webhp#q=histedit+drop
In 2022 I do use evolve extension. It is one of the best extensions for this purpose.
To prune unwanted changeset, if you for example did a quick hack to get the code working:
$ echo 'debug hack' >> file1.c
$ hg commit -m 'debug hack'
Now you have a proper patch you can do hg prune .:
$ hg prune .
1 files updated, 0 files merged, 0 files removed, 0 files unresolved
working directory is now at 2a39221aaebb
1 changesets pruned
If you push the change to the remote repository you will find only obsolescence markers:
$ hg push
searching for changes
no changes found
remote: 1 new obsolescence markers
To check the changes to your local repo you can pull from the remote one:
$ hg pull
pulling from ssh://userid#server/repo
searching for changes
no changes found

Copy Mercurial repository with uncommitted changes

I have an mercurial repositry a bitbucket.org and a clone on my wokstation. The clone has some uncommited (unfished) work in it. I have to copy these clone to my laptop because I will be on a trip for one or two weeks and want to do some work.
Is there a simple and save way to copy the repository with its uncommited changes to another device? I knew I could clone the repo from the workstation to my laptop but this won't copy uncommited work.
Simply copy the entire repository's folder.
Just commit that work. That work needs to be finished to be committed is left-over CVS/SVN thinking. Commit it, and then update to its parent and work on whatever else you want to work on. When eventually the work is done you're pushing a changegroup not individual changesets, so no one will have the uncompiling stage at the end of those interstitial changesets on them.
Avoiding committing work in Mercurial (using shelve, attic, copying repos, etc.) is the only way to lose work -- avoid it.
I prefer my first answer (commit it) but if you positively can't bring yourself to commit unfinished work then you should be using Mercurial Queues with a patch queue that lives in its own repository. This is easily done with:
hg qinit --create-repo
Then you import your uncomitted changes as a patch using:
hg qnew --force name-for-this-work
then you can:
hg qcommit -m "work in progress"
Then you can qclone that repo and get both the work in progress and the base repository on which it's overlayed. More details are available in the Mercurial book's chapter on queues.
Really, though, there's just never a good reason to have uncommitted work for more than an hour or two.