Mercurial: Switch working directory to branch without losing changes? - mercurial

Let's say that I have a named branch 'B1' which I'm doing feature development on.
I am at a good stopping point before a demo though not done with the feature so I:
hg up default
hg merge B1
hg ci -m "merged in feature drop"
hg push
Now I continue working for a half an hour or so and go to commit only to realize that I forgot to update back to B1 and that my current working directory is on default - uhoh. In theory I should be able to just mark my working directory parent as the tip of B1 - is there an easy way to do this?
I could of course commit, update back to B1, and merge my changes back, but then there's an unstable changeset in default and this happens often enough to me that I would like a real solution.

Two ways. First, the obvious way:
hg diff > foo
hg up -C b1
hg import --no-commit foo
rm foo
Second, the magical way:
hg up -r 'ancestor(., b1)' # take working dir back to the fork point
hg up b1 # take it forward to the branch head
This way involves merges. Depending on how much your branches have diverged, this may be painless. Or it may be complicated, and you may make a mess of your changes that you haven't saved anywhere. Which is why even magicians like myself prefer to do it the first way.

I would use the shelve extension. I think it’s distributed along with TortoiseHg, you can also use it from the UI:
hg shelve --all
hg up B1
hg unshelve

Rebase extension allow you to change parent for any commit for wrongly commited changeset.
If you want just change branch for future commit - MQ (as mentioned) or Shelve

Typically for this sort of dynamic approach, I favor mercurial queues.
In your situation, what I would do would be to create a patch on default with the changes, pop the patch off, switch over to B1, and apply the patch.
It goes something like:
hg qnew OOPSPATCH
hg qrefresh
hg qpop
hg up B1
hg qpush
<hack hack>
hg qrefresh
hg qfinish

All you need is simple hg up -m B1
From hg up --help:
options:
…
-m --merge merge uncommitted changes
…

Related

Can changes made by strip be reflected in the public repo?

Let's say I have this:
hg clone public_repo my_repo
touch a b c d
hg add .
hg commit -m a a
hg commit -m b b
hg commit -m c c
hg commit -m d d
hg push
# let's say revX is the revision that added a
hg strip revX
In my repository's history, the commits are gone. However, if I try to do a push after the strip, it tells me no changes found. Can the strip be applied to the public repo?
EDIT: the question is just hypothetical :). I am not in this situation, I just thought it would be interesting to find out how this works.
You need to run hg strip there. If it's bitbucket repo, you can do it from the admin panel. If not, SSH.
This is not possible. You have to strip the public repo as well.
hg strip just takes away changesets. It does not perform an "adding" operation which could be pushed.
In the exact example you provide, you could just hg rollback on the public repo.
Let me pretend you're asking a slightly different question: I've stripped part of my repository history, how do I propagate this change to other dev's repositories?
Mercurial offers no way of propagating stripping in the same way it propagates adding changesets. So you have to come up with your own way.
Bitbucket, for example, has an updates list (on the repo summary page, if my memory serves me well). If you do a strip, Bitbucket displays there something like this:
Changeset 12345abcdef was stripped from the repository, please run hg strip 12345abcdef locally.
When we had to propagate stripping of part of an old branch in our shop, here's what we did:
Stripped the changesets on the server.
Created a batch file named strip.bat on the default branch of the repo containing the command we'd run on the server, i.e. hg strip 1234567890.
Told everybody that whenever they cannot push because “push creates new remote heads” for no apparent reason, this means they should run strip.bat.
In case we ever need to strip something again, we just add another hg strip in the batch file.
P.S. Yes it's better not to strip, e.g. use backout to commit inverse changesets. Sometimes that's not an option: if you mistakenly merged branch a into branch b when you wanted the merge b into a, you're trapped. Even if you backout the merge changeset on feature, the merged changesets from a are already marked as merged, and you'll have a hard time doing another merge of these branches.
The correct and safe way to remove unwanted changes that made it to the wild is to hg backout them.
Sometimes it is not possible to strip or backout a change, for example if it was a merge revision and you don't have admin access to the server. One method that does work is to branch the last good revision and then close the bad head.
hg up badrev^ (Go to the revision before the bad one)
touch dummy && hg add dummy && hg ci -m 'dummy' && hg rm dummy && hg ci --amend -m 'Fix accidental merge' (Create a second head with no changes from the good revision)
hg up badrev (Go to the bad revision)
hg ci --close-branch -m 'Close bad head' (Close the bad head)
hg push

Placing recent commits in a separate (named) branch in Mercurial (Hg)

If I have several commits made to the default branch since the last push, is it possible to go back, and move those commits into a separate named branch?
That is, I have:
A--B--C--D
and I want:
A
\
B--C--D
I hope this makes sense?
Take a look at the Transplant extension.
But personally, I'd do it using MQ, like so:
# assuming revs 1 and 2 are the ones we want to move
hg qimport -r1:2
# qimport creates a patch for each changeset
>hg qapplied
1.diff
2.diff
# pop the patches, to save for later
>hg qpop -a
popping 2.diff
popping 1.diff
patch queue now empty
# switch branches
>hg branch my-branch
marked working directory as branch my-branch
# push our saved changesets, essentially rebasing on the new branch
>hg qpush -a
applying 1.diff
applying 2.diff
now at: 2.diff
# make the patches part of permanent history
>hg qfin -a
You could probably also bend the Rebase extension to suit this purpose, if you prefer.
If the commits are still in only your local repository and have not been pushed to any other one, then yes, you can re-arrange them with fairly minimal trouble. If they have moved beyond just your local repo, however, you will run into a lot of trouble.
To re-arrange commits, you want to use the MQ extension. Here's a tutorial, since it explains things better than I could here.

ignore non-existant files when merging in Mercurial

I am working with a repository with stable and experimental branches. Sometimes I add a file on the experimental branch that is not yet ready for the stable branch. When I merge, I want to merge the changes in the files that are common to both branches, but ignore the files that don't exist on one of the branches.
Here's a simple example:
hg init
hg branch stable
(create file A)
hg add A
hg commit -m "Added A"
hg branch exp
(create file B)
hg add B
hg commit -m "Added B, which is really experimental"
(modify file A)
hg commit -m "Some changes to A"
hg update stable
hg merge exp
However I change the merge tool configuration, Mercurial always seems to take B along with the merge. Since it doesn't exist on the stable branch, it's never a conflict.
I could do the following:
hg update stable
hg merge exp
hg commit -m "Merged"
hg revert -r 0 B
but that requires me to know which files need reverting.
Any thoughts on the simplest way to make the merge ignore files that don't exist on one branch, and preferably do it automatically?
You cannot ask Mercurial to do what you want.
You do not merge individual files, you merge the entire branch, which means that all the files that are part of the branch becomes part of the merge. This is how Mercurial is designed and how it operates.
Now, you could revert/forget/delete the files you don't want before you commit, but then you're just setting yourself up for disaster later.
I recommend you separate things you want to keep from things you don't know if you want to keep so that you can merge one branch and let the other be separate for now.

Mercurial Getting out of a bad merge

I just merged branch A into B, and for some reason the merge did not go well. I want to revert B back to where it was before the merge and try again like it never happened before. I was thinking of just doing
hg clone myrepo newrepo -r A -r 12345
where 12345 is the revision number before B's bad merge commit
I think this works, but I have a lot of other branches (most of which are closed using commit --close-branch) and this puts those branches back to an inactive state.
Is there a way to clone everything except revision 123456 or something? (where 123456 is the bad commit on B)
Assuming you have not pushed the merge changeset to any public location, the easiest solution is to use the hg strip command that comes with the Mercurial Queues (i.e. mq) extension.
From the wiki:
hg strip rev removes the rev revision
and all its descendants from a
repository. To remove an unwanted
branch, you would specify the first
revision specific to that branch. By
default, hg strip will place a backup
in the .hg/strip-backup/ directory. If
strip turned out to be a bad idea, you
can restore with hg unbundle
.hg/strip-backup/filename.
It might not be as nice as hg rollback, but usually what I do is update to head A, merge in previous head B, check that I got it right this time, and then dummy-merge away the bad merge.
I hope I'm understanding your situation correctly. If I am you should be able to update to the revision of B before the merge, give that revision a new branch name, merge A in to it, and continue on. You'll probably want to mark the original B branch as closed.
$ hg up 12345 #12345 is the revision of B prior to the merge
$ hg branch B-take2
$ hg merge A
$ hg commit -m 'merge A in to B-take2'
$ hg up B
$ hg commit --close-branch -m 'mark original B branch as closed'
Is it too late to use the hg rollback command? If so, try the hg backout command.

With Mercurial, if there are two local clones, can you push from one branch to another branch?

If there are two branches, and I have been doing work on the default branch, I think one way to push to the foo branch of the other clone is
cd ~/development/clone2
hg up default
hg pull ~/developmet/clone1
hg up foo
hg merge default
or
cd ~/development/clone1
hg up default
hg push ~/developmet/clone2
cd ~/development/clone2
hg up foo
hg merge default
These 2 methods work exactly the same? (one is a pull, one is a push).
Is there an easier way to directly push clone1's default branch to clone2's foo branch? thanks.
(I use clone 1 to see all the changes I have done (without seeing anybody else's changes), and use clone2 to merge and integrate with other team members)
You can always push and pull a single revision and all of it ancestors using:
hg push -r revision ~/development/clone1
or
hg pull -r revision ~/development/clone2
There's no way to "push to another branch" because you'll always have to merge the two different branches manually
Both methods you described work exactly the same, but the first one is recommended (Always do the merge work in your clone, not the integration repository or somebody else's clone)
Maybe is an intentional omission but in both examples you have to commit the result of the merge and in the first example you have to push the merge changeset back to clone2
So in ~/development/clone1 do:
hg up default
hg pull -u ~/development/clone2
hg up foo
hg merge default
hg ci -m 'merged default into foo'
hg push ~/development/clone2
If you do this a lot you may consider adding this lines to your ~/development/clone1/.hg/hgrc file
[paths]
default = ~/development/clone2
This way you can omit the repository path when you're pulling and pushing from the integration repository