there is a new feature in mercurial 3, called 'graft' (graft to local).
it does a good job of moving a change-set to a different branch.
Is there a way to "COPY" a change-set to a branch?
I am interested in in moving stuff from the QA branch to the production branch, but I still need the code to reside in QA. So what I really want is a copy. I just found this and have only tried a few things, maybe it'll all become clear with some more tinkering and reading...
Does anyone have a better way of 'cherry picking' change-sets to move cross branch (or trunk)???
Graft copies changesets, it doesn't move them. From hg help graft (emphasis mine):
This command uses Mercurial's merge logic to copy individual changes from other branches without merging branches in the history graph. This is sometimes known as 'backporting' or 'cherry-picking'. By default, graft will copy user, date, and description from the source changesets.
Related
I have two repositories with tho different mercurual named branches, say V1 and V2. The branches are divergent since about one-two years. I'd like to graft some changesets from one repo into the other, without pulling the changes.
I don't want to pull the changes for multiple reasons.
I don't want to conflict developers with history of multiple branches, because there will be enough local branches to care about.
I want to have single branch central repos and developers could accidently push the second branch. The central branches would interact with SVN and should have only one branch per repo. I know I could use central hooks, to prevent such a push, but I don't want questions like, can't push, or how can I do that.
The size of the repo would grow to multiple gigabytes (before pull about 700MB). As I understand, it's because of deficites of current mercurial storage format.
I know, the transplant extension can do the work. I tried it, but I can't force other developers to handle rejects instead of simply use a merge tool. Is there an other way?
In fact there are more then two repos with each a branch, but for the example simplicity two should be enough.
You might be able to do the work in an intermediate repo:
Pull in the changes
Do whatever grafting/rebasing/transplanting you need
Strip out the things you pulled in step 1. or if that doesn't work:
Pull only the changes from the branch you want into the actual repo
You'd end up with a repository that includes your desired change sets, but not all the history from the unwanted branch.
Follow-up to #DanMan
Pull needed branch into intermediate repo
Strip unwanted changesets in clone
hg pull CLONE in real target
Write a tool, a hg-extension or extend the graft command so it can graft from a second repository, similar to the transplant extension.
Yes, the implementation is not so easy as adding the second-repo-functionality in the transplant command. The transplant extension simply uses a patch from an other repo instead of one from own repo. But I think also for graft there is no technical reason, not to do that.
If I understand right, grafting of a single file change is not more than calling the merge tool with the files:
(base) the parent of the to-graft changeset
(my changes) the target revision, on which to graft
(theirs) the to-graft refision
So in order to graft a file change from an other repo, the whole file from other repo is needed before the to-graft changeset was applied (base) and after it was applied (theirs). Technically it should be no problem.
Additionally the implementation
need to determine, which files are affected by the changeset to graft
need to handle deletions correctly
need to handle file renamings (not sure, how complicated it is)
All that should be possible, I see no real technical problems.
I am new to Mercurial and still somehow in the evaluation process, so these four concepts are kind of confusing for me. Some are mentioned to be an equivalent to Git's Staging/Index concept, or some even a better one than Git's Staging.
How do the four commands hg graft, hg record, hg qrecord and hg shelve (and hg transplant, but this is explained in Graft vs. Transplant already) compare to each other, and how the concepts of queues and the dirstate? In which use cases is one choosen over the other?
I know there are help pages for each one, but it still is difficult to figure out what each one does as VCS in general is a new topic for me.
The design of Mercurial simply does not include the concept of a staging area. That is, there is no intermediate state between local modification and commit.
Here is an overview of each of the concepts you mentioned:
hg graft is the equivalent of git cherry-pick. It copies a commit from one branch to another. A typical use case for this feature is to copy a bug fix from one release branch to another. This command replaces the older (and now obsolete) hg transplant extension.
hg record and hg qrecord are similar to git add --patch. They allow you to interactively select hunks for commit. So if you modified several different areas of one file, you could select which areas (i.e. hunks) you actually want to commit and which you want to leave as local modifications.
qrecord is only available if you have mq enabled. It commits to an mq patch rather than a standard commit.
hg shelve is similar to git stash. It allows you to temporarily set aside local modifications to your files (or hunks of a file). These modifications can then be unshelved when you are ready for them.
dirstate is an internal class of of the Mercurial source code. It is not exposed to the user.
Mercurial Queues (also know as mq) are probably the closest you will get to a staging area in Mercurial. Here is a description from the Mercurial wiki:
Changes are maintained as patches which are committed into Mercurial.
Commits can be removed or reordered, and the underlying patch can be
refreshed based on changes made in the working directory. The patch
directory can also be placed under revision control, so you can have a
separate history of changes made to your patches.
mq is often used to polish/rework commits that you are testing locally, but have not pushed to a public location. Some people also use it to maintain a set of modifications to 3rd party code.
I've forked a project from the internet, and I want to write some new features. I want to write several orthogonal features at the same time, (eg. debug helpers, new feature X, new feature Y), and have the code for all of them in my current directory, but when I commit, I want to be able to say "these files go to branch 'debug'", "those files go to branch 'feature X'", etc. Where these are branches in the 'hg branches' sense.
The reason for this is the project upstream may not want to merge my debug helpers or hacked bug fixes, but I certainly want to use them whilst developing my features.
Effectively, I just want to apply the changes in those files to the branch, but keep several branches checked out & merged to my current working directory.
Is this possible? Perhaps there's some hg extension to do this?
Thanks!
Look at mercurial queues (MQ) for things like debug helpers or local hacks. Very useful for patches that you only want locally and may want to apply to any revision/branch.
Doing the same thing with branches becomes tedious IMHO as you have to be very careful to do the changes for debug and features on different branches, and then merge them in to a local, throwaway branch in order to run anything. You can end up with lots of changesets on the feature branch that leave the tree in a broken state because you can only test after you commit.
I don't fully understand why you'd you would want to do things that way. If your features are orthogonal, you can work on them independently until they are ready to be merged. That is exactly what branches are for after all!
But to answer your question: you could commit on a branch and then, as a matter of workflow, always up to default and merge it in. That would keep the default branch as the sum of the other features. You would need to update to the feature branch before you commit, though and that could get tedious.
The other option for post-facto determining which branch you want to commit to is to use the rebase extension. In this case, you'd commit your changes and then do hg rebase -d targetBranch.
I don't recommend using history revisions as part of your standard workflow, though. That smells to me.
I faced today my first mercurial problem. I was in my repo, I modified a file and I did a
hg commit
hg pull
followed by
hg update
hg rollback
to repair what I've done, (but actually I didn't push anything)
The problem is that when I did the pull (that I should do before the commit, the head changed and so hg heads looks like :
- Modif from yesterday
- My modif
- Modif from last week
and now I see that someone also did another modification (via the http interface). What should I do to repair my local repo, (if possible modifying my summary) and push it after the 2 others modifications.
Thanks a lot. Quiet confusing, was easier on my "one-man" repo..
Your local repo doesn't need "repairing". This is a very standard case that you will see often if you use Mercurial a lot.
The issue is multiple heads.
You can either merge your heads, assuming your working directory is your version and there is only the other head:
hg merge
This will result in a merge changeset (same as if you were merging across branches).
Or you can enable the rebase extension to re-base your version onto the tip of the branch (the other head):
hg rebase --source<YourVersionNumber> --dest<TipVersionNumber>
This will not result in a merge changeset, and will simply transplant your changes on top of the changeset you specify as if they were born of that changeset all along (hence rebase or "new"basing).
Multiple heads is a funny sort of inner-branch branching... you can continue checking stuff in against your own head and change between heads using hg update. We block multiple heads per branch on our server, so our push would fail. I'd advise keeping multiple heads local as they are less clear-cut than branches.
I tend to work with Mercurial in one of two ways:
If the work is large in scale I will branch it off and follow Continuous Integration practices (constantly merging the main branch into my own etc). I then re-merge back into main when I am happy with the end result.
If the work is small in scale I will simply work against main branch and "merge" heads every so often. I say "merge" as I usually use rebase. Re-basing works great if the changes are simple and conflicts are unlikely.
My hard and fast rule: if I can't use rebase I put it on a branch born of main.
I'm an ex SVN user trying to work out the best way to do branched development in hg. My project is fairly new currently has no branches. A friend of mine suggested that making a local clone of the repos. then working in that was better than using a named branch.
So if I use this model, would the workflow be:
[say original project has been cloned to be in c:\projects\sk\tracker]
hg clone https:[url of repos] tracker_featurex [to be issued from c:\projects\sk]
change to subdir tracker_featurex
checkin and push as per normal
[optional, how do I pull changes from the main repos. into this one?]
[final step, how do I get changes from this clone back into the main trunk?]
I need help on whether this workflow is correct and what the exact commands would be for the two steps in the [] braces.
Thanks a great deal to anyone who can help,
Fred
I would recommend you take a look at Steve Losh's post on branching in Mercurial: http://stevelosh.com/blog/2009/08/a-guide-to-branching-in-mercurial/
He goes over various types of branches (clones, bookmarks, named branches, anonymous branches) as well as the commands you would run for each. There are pros and cons to all of them. Local clones are ok if you are the only developer but they are not as useful in a workflow where more than one developer needs to work on a branch. The claim that clones are universally better than named branches is a myth. You should find a branching model that fits your workflow.
Update:
If you do want to do local clones you can move you changes using hg push from the new workspace (Assuming you have a Projects folder and a repo named test):
Projects> hg clone test test-new-feature
Projects> cd test-new-feature
Projects/test-new-feature> <do some work>
Projects/test-new-feature> hg commit -m "Work is done."
Projects/test> <Might need a pull/merge here>
Projects/test-new-feature> hg push
If there are changes in the test repo you need to pull/merge them before pushing.
You can also hg pull from the original workspace:
Projects> hg clone test test-new-feature
Projects> cd test-new-feature
Projects/test-new-feature> <do some work>
Projects/test-new-feature> hg commit -m "Work is done."
Projects/test-new-feature> cd ../test
Projects/test> hg pull ../test-new-feature
This might create multiple heads in the test repo and you would need to merge/commit.
Projects/test> hg merge
Projects/test> hg commit -m "Merged in new-feature."
Either are good options. I might recommend pulling rather than pushing. The main difference to me is the location of the merge step. I think pulling from the feature repo makes the history a little more readable.
I am fledgling to Hg, so take what I say with a word of caution :-)
I love having named branches, but use them very judiciously! There are downsides to the approach I use below, but it works well for my current environment which is a small shop. I don't mind preserving history forever and I'm not concerned with reducing the number of commits (but Mq/record/etc can address this latter bit).
This is how I use branches in the code I work on:
Default branch.
This is built on the build server.
This should only have one head.
This should always compile.
This should always be the "best effort" at completing bugs/features.
"Workbench" branch.
This can have multiple heads.
Anonymous branches are encouraged. Shared bookmarks used to "name" active anonymous branches.
The state should be almost always compilable, but it is not a requirement.
Represents "work in progress".
Okay, so this is what my process might look like this: (I've excluded pull/push/merge-theirs steps).
I get a bug report in.
I switch to "workbench" tip (or whatever revision is appropriate).
I fix the bug, possibly committing several times. (I really should learn to use queues or record, etc.)
(If I am interrupted in the above process, e.g. have to work on a different bug, or am otherwise side-tracked I will create a new head above where #2, or as appropriate. I may give the current anonymous branch tip a name with a bookmark, or I may not.)
Once complete, I merge the relevant branch/changes into "default" and hopefully the build server still loves me :-)
I think the best thing to do is forget about how branches in SVN worked. They are not liked named branches at all and anyone who says otherwise is latching onto the fact they both have "names" and not much more. Every branch in Hg is part of a "named branch" (that is, has a name associated with it, be it "default" or "workbench" or otherwise). But it doesn't matter, except for organization: a branch is a branch and it doesn't matter if it's referring to the "tip" of an anonymous branch or the tip of the only head (really an anonymous branch itself) in a named branch.
Try a few things, use what works best :)
making a local clone of the repos. then working in that was better than using a named branch.
Overly dramatic and ambitious statement in common. When you clone-per-feature, you have only one branch (named branch) per repo, but nothing more (practically, briefly speaking).
When feature is finished, you have to "push to parent"|"pull from clone" in order to return changes back. At this stage, if some work was done in parent repo after clone, anonymous branch will appear (+1 head) and merge is a must (same as for work in named brach in one repo), but, it named brach can tells something fast later (you use good names, isn't it?), anonymous branch tells almost nothing without additional tricks (bookmarks, f.e). Part of my repo below as example of work in clone with intermediate pulls and must-merges after pulls/ (sorry, russian commit-messages) and even I can't recall now, why I had repo cloned for editorials - maybe I just play with Clones-Workflow