Mercurial : How to revert to a prev version after performing push - mercurial

I have two branches let's say A and B. I have done few changes in A and committed my code into A then i have merged A into B and did a push.
Now the problem is i have added some unnecessary files into B.
I want o revert to a prev version of B. I have see few solutions to perform hg update -r and then forcefully push it to the repo which might lead to new heads which i don't want to do.
Bare me for the explanation, doing this for the first time. Thanks.
I want to revert back to 3313 revision

you can go on your head, remove the unnecessary files, commit and push.
Go to your branch B
hg update -r 3316
Remove the files, commit and push
hg forget yourfilethere
hg commit -m "Remove unecessary files"
hg push
let me know if it helps!

If what you want is to remove or modify a pushed revision, then I am afraid Mercurial (by design) does not support this. (You can change the phase of a revision to 'draft' and strip or amend it, but when you pull again the old revision will re-appear.)
If you really need to remove the revision (e.g. it contains some huge files), then there is nothing you can do about it on your local repository; the only way this can be done is on the remote repository (e.g. having the administrator run hg strip directly on the remote repository, or some equivalent thereof; the BitBucket interface does support stripping a revision).
We have had a similar problem at work, where some user committed very large files to the repository, and a lot of work was done on the repository afterwards. The only way we were to solve it was using the 'convert' extension to remove the files, and then pushing into a brand new repository. (If we had just pushed the converted repository to the existing one, this would just have created duplicate revisions starting from the point where the bad files were committed.)

Related

How do I put a bunch of uncommitted changes aside while working on something else

If I have a bunch of uncommitted changes and want to set it aside while working on something else instead, and then later (f.i. after several days) come back to it and proceed working. What would be the easiest workflow to accomplish this? (So far I have only experience with Mercurial's basic functionality). My usual method was to create a new branch using clone, but there might be better ways.
You have a handful options:
Shelve the items. This saves the changes and removes them from the working directory so the branch can continue. It doesn't create a change-set.
hg shelve --all --name "UnfinishedChanges"
hg unshelve --name "UnfinishedChanges"
Update/Edit: Newer versions of mercurial may need to use
hg shelve -n "UnfinishedChanges"
hg unshelve "UnfinishedChanges"
You can still use --name as an alternative to -n, but mercurial doesn't seem to like --name anymore. Additionally, the --all is no longer required and mercurial will in fact freak out over it.
Patch queue the items using mq. This isn't too dissimilar to shelve in some respects, but behaves differently. The end result is the same, changes are removed and can be optionally re-applied later. When pushed, the patches are logical change-sets, when popped they are saved elsewhere and are not part of change-set history.
hg qnew "UnfinishedWork"
hg qrefresh
hg qpop
hg qpush "UnfinishedWork"
Commit them locally, update to the previous change-set and continue working and make use of anonymous branches (or multiple heads). If you then want the changes, you can merge heads. If you don't want the changes, you can strip the change-set.
hg commit -m"Commiting unfinished work in-line."
hg update -r<previous revision>
hg strip -r<revision of temporary commit>
Commit them to a named branch. The workflow then becomes the same as option 3 - merge or strip when you are ready.
hg branch "NewBranch"
hg commit -m"Commiting unfinished work to temporary named branch."
hg update <previous branch name>
Personally I use option 3 or 4 as I don't mind stripping change-sets or checking-in partial code (so long as that doesn't eventually get pushed). This can be used in conjunction with the new Phase stuff to hide your local change-sets from other users if need-be.
I also use the rebase command to move change-sets around to avoid merges where a merge wouldn't add anything to the history of the code. Merges I tend to save for activity between important branches (such as release branches), or activity from a longer-lived feature branch. There is also the histedit command I use for compressing change-sets where the "chattiness" of them reduces the value.
Patch queues are also a common mechanism for doing this, but they have stack semantics. You push and pop patches, but a patch that is "underneath" another patch in the stack requires that the one on top of it be pushed also.
Warning, as with all these options, if the files have more changes since the temporary changes that you've shelved / queued / branched, there will be merge resolution required when un-shelving / pushing / merging.
Personally, I don't like any of the answers posted so far:
I don't like clone branching because I like each project to have only one directory. Working on different directories at the same time completly messes the history of recent files of my editors. I always end up changing the wrong file. So I don't do that anymore.
I use shelve for quick fixes (just to move my uncommited changes to another branch, if I realize I'm at the wrong one). You are talking about days, no way I'd shelve something for days.
I think mq is too complicated for such an ordinary sittuation
I think the best way is to simply commit your changes, than you go back to the changeset before you start these changes and work from there. There are some minor issues, let me illustrate:
Let's say you have the changeset A. Than you start your changes. At this point you want set it aside for a while. First of all, commit your work:
hg ci -m "Working on new stuff"
If you want, you can add a bookmark to make it easier to come back later. I always create bookmarks to my anonymous branches.
hg bookmark new-stuff
Go back to the changeset before these modifications
hg update A
From here, you work and generate the changeset C. Now you have 2 heads (B and C), you'll be warned when you try to push. You can push only one branch by specifying the head of that branch:
hg push -r C
Or you can change the phase of the new-stuff branch to secret. Secret changesets won't be pushed.
hg phase -r new-stuff --secret --force
To keep local uncommited changes, easiest way for me is just to save them as a patch file.
hg diff > /tmp/`hg id -i`.patch
and when you need to return to previous state:
hg up <REV_WHERE_SAVED>
hg patch --no-commit /tmp/<REV_WHERE_SAVED>.patch
You can just clone your repo multiple times. I tend to have a root clone, then multiple childs from there. Example:
MyProject.Root
MyProject.BugFix1
MyProject.BugFix2
MyProject.FeatureChange1
MyProject.FeatureChange2
The 4 childs are all cloned from the root and push/pull to/from the root. The root then push/pulls from the master repo on the network/internet somewhere. The root acts as your sort of personal staging area.
So in your case, you'd just clone up a new repo and start working. Leave your 'shelved' work alone in the other repo. It's that simple.
The only downside is disk space usage, but if that were a concern you'd not be using DVCS at all anyway ;) Oh and it does kind of pollute your Visual Studio "recent projects" list, but what the hey.
[Edit following comments] :-
To conclude then... what you're doing is completely fine and normal. I would argue it is the best possible way to work when the following are true: 1) it is short-lived 2) you don't need to collaborate with other developers 3) the changes don't need to leave your PC until commit/push time.

Mercurial: how to amend the last commit?

I'm looking for a counter-part of git commit --amend in Mercurial, i.e. a way to modify the commit which my working copy is linked to. I'm only interested in the last commit, not an arbitrary earlier commit.
The requirements for this amend-procedure are:
if possible, it should not require any extensions. It must not require non-default extensions, i.e. extensions which do not come with an official Mercurial installation.
if the commit to amend is one head of my current branch, no new head should be created. If the commit is not head, a new head may be created.
the procedure should be safe in a way that if for whatever reasons the amending fails, I want to have the same working copy and repository state restored as before the amending. With other words, if the amending itself can fail, there should be a fail-safe procedure to restore the working copy and repository state. I'm referring to "failures" which lie in the nature of the amend-procedure (like e.g. conflicts), not to file-system-related problems (like access restrictions, not being able to lock a file for writing, ...)
Update (1):
the procedure must be automatable, so it can be performed by a GUI client without any user interaction required.
Update (2):
files in the working directory must not be touched (there may be file system locks on certain modified files). This especially means, that a possible approach may at no point require a clean working directory.
With the release of Mercurial 2.2, you can use the --amend option with hg commit to update the last commit with the current working directory
From the command line reference:
The --amend flag can be used to amend the parent of the working directory with a new commit that contains the changes in the parent in addition to those currently reported by hg status, if there are any. The old commit is stored in a backup bundle in .hg/strip-backup (see hg help bundle and hg help unbundle on how to restore it).
Message, user and date are taken from the amended commit unless specified. When a message isn't specified on the command line, the editor will open with the message of the amended commit.
The great thing is that this mechanism is "safe", because it relies on the relatively new "Phases" feature to prevent updates that would change history that's already been made available outside of the local repository.
You have 3 options to edit commits in Mercurial:
hg strip --keep --rev -1 undo the last (1) commit(s), so you can do it again (see this answer for more information).
Using the MQ extension, which is shipped with Mercurial
Even if it isn't shipped with Mercurial, the Histedit extension is worth mentioning
You can also have a look on the Editing History page of the Mercurial wiki.
In short, editing history is really hard and discouraged. And if you've already pushed your changes, there's barely nothing you can do, except if you have total control of all the other clones.
I'm not really familiar with the git commit --amend command, but AFAIK, Histedit is what seems to be the closest approach, but sadly it isn't shipped with Mercurial. MQ is really complicated to use, but you can do nearly anything with it.
GUI equivalent for hg commit --amend:
This also works from TortoiseHG's GUI (I'm using v2.5):
Swich to the 'Commit' view or, in the workbench view, select the 'working directory' entry.
The 'Commit' button has an option named 'Amend current revision' (click the button's drop-down arrow to find it).
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\/
Caveat emptor:
This extra option will only be enabled if the mercurial version is at least
2.2.0, and if the current revision is not public, is not a patch and has no
children. [...]
Clicking the button will call
'commit --amend' to 'amend' the revision.
More info about this on the THG dev channel
I'm tuning into what krtek has written. More specifically solution 1:
Assumptions:
you've committed one (!) changeset but have not pushed it yet
you want to modify this changeset (e.g. add, remove or change files and/or the commit message)
Solution:
use hg rollback to undo the last commit
commit again with the new changes in place
The rollback really undoes the last operation. Its way of working is quite simple: normal operations in HG will only append to files; this includes a commit. Mercurial keeps track of the file lengths of the last transaction and can therefore completely undo one step by truncating the files back to their old lengths.
Assuming that you have not yet propagated your changes, here is what you can do.
Add to your .hgrc:
[extensions]
mq =
In your repository:
hg qimport -r0:tip
hg qpop -a
Of course you need not start with revision zero or pop all patches, for the last just one pop (hg qpop) suffices (see below).
remove the last entry in the .hg/patches/series file, or the patches you do not like. Reordering is possible too.
hg qpush -a; hg qfinish -a
remove the .diff files (unapplied patches) still in .hg/patches (should be one in your case).
If you don't want to take back all of your patch, you can edit it by using hg qimport -r0:tip (or similar), then edit stuff and use hg qrefresh to merge the changes into the topmost patch on your stack. Read hg help qrefresh.
By editing .hg/patches/series, you can even remove several patches, or reorder some. If your last revision is 99, you may just use hg qimport -r98:tip; hg qpop; [edit series file]; hg qpush -a; hg qfinish -a.
Of course, this procedure is highly discouraged and risky. Make a backup of everything before you do this!
As a sidenote, I've done it zillions of times on private-only repositories.
Recent versions of Mercurial include the evolve extension which provides the hg amend command. This allows amending a commit without losing the pre-amend history in your version control.
hg amend [OPTION]... [FILE]...
aliases: refresh
combine a changeset with updates and replace it with a new one
Commits a new changeset incorporating both the changes to the given files
and all the changes from the current parent changeset into the repository.
See 'hg commit' for details about committing changes.
If you don't specify -m, the parent's message will be reused.
Behind the scenes, Mercurial first commits the update as a regular child
of the current parent. Then it creates a new commit on the parent's
parents with the updated contents. Then it changes the working copy parent
to this new combined changeset. Finally, the old changeset and its update
are hidden from 'hg log' (unless you use --hidden with log).
See https://www.mercurial-scm.org/doc/evolution/user-guide.html#example-3-amend-a-changeset-with-evolve for a complete description of the evolve extension.
Might not solve all the problems in the original question, but since this seems to be the de facto post on how mercurial can amend to previous commit, I'll add my 2 cents worth of information.
If you are like me, and only wish to modify the previous commit message (fix a typo etc) without adding any files, this will work
hg commit -X 'glob:**' --amend
Without any include or exclude patterns hg commit will by default include all files in working directory. Applying pattern -X 'glob:**' will exclude all possible files, allowing only to modify the commit message.
Functionally it is same as git commit --amend when there are no files in index/stage.
Another solution could be use the uncommit command to exclude specific file from current commit.
hg uncommit [file/directory]
This is very helpful when you want to keep current commit and deselect some files from commit (especially helpful for files/directories have been deleted).

Mercurial clone cleanup to match upstream

I have a hg clone of a repository into which I have done numerous changes locally over a few months and pushed them to my clone at google code. Unfortunately as a noob I committed a whole bunch of changes on the default branch.
Now I would like to make sure my current default is EXACTLY as upstream and then I can do proper branching off default and only working on the branches..
However how do I do that cleanup though?
For reference my clone is http://code.google.com/r/mosabua-roboguice/source/browse
PS: I got my self into the same problem with git and got that cleaned up: Cleanup git master branch and move some commit to new branch?
First, there's nothing wrong with committing on the default branch. You generally don't want to create a separate named branch for every task in Mercurial, because named branches are forever. You might want to look at the bookmark feature for something closer to git branches ("hg help bookmarks"). So if the only thing wrong with your existing changesets is that they are on the default branch, then there really is nothing wrong with them. Don't worry about it.
However, if you really want to start afresh, the obvious, straightforward thing to do is reclone from upstream. You can keep your messy changesets by moving the existing repo and recloning. Then transplant the changesets from the old repo into the new one on a branch of your choosing.
If you don't want to spend the time/bandwidth for a new clone, you can use the (advanced, dangerous, not for beginners) strip command. First, you have to enable the mq extension (google it or see the manual -- I'm deliberately not explaining it here because it's dangerous). Then run
hg strip 'outgoing("http://upstream/path/to/repo")'
Note that I'm using the revsets feature added in Mercurial 1.7 here. If you're using an older version, there's no easy way to do this.
The best way to do this is with two clones. When working with a remote repo I don't control I always keep a local clone called 'virgin' to which I make no changes. For example:
hg clone -U https://code.google.com/r/mosabua-roboguice-clean/ mosabua-roboguice-clean-virgin
hg clone mosabua-roboguice-clean-virgin mosabua-roboguice-clean-working
Note that because Mercurial uses hard links for local clones and because that first clone was a clone with -U (no working directory (bare repo in git terms)) this takes up no additional disk space.
Work all you want in robo-guice working and pull in robo-guice virgin to see what's going on upstream, and pull again in roboguice-working to get upstream changes.
You can do something like this after the fact by creating a new clone of the remote repo and if diskspace is precious use the relink extension to associate them.
Preface - all history changes have sense only for non-published repos. You'll have to push to GoogleCode's repo from scratch after editing local history (delete repo on GC, create empty, push) - otherwise you'll gust get one more HEAD in default branch
Manfred
Easy (but not short) way - default only+MQ
as Greg mentioned, install MQ
move all your commits into MQ-patches on top of upstream code
leave your changes as pathes forever
check, edit if nesessary and re-integrate patches after each upstream pull (this way your own CG-repo without MQ-patches will become identical to upstream)
More complex - MQ in the middle + separate branches
above
above
create named branch, switch to it
"Finish" patches
Pull upstream, merge with your branch changes (from defaut to yourbranch)
Commit your changes only into yourbranch
Rebasing
Enable rebase extension
Create named branch (with changeset in it? TBT)
Rebase your changesets to the new ancestor, test results
See 5-6 from "More complex" chapter
Perhaps you could try the Convert extension. It can bring a repository in a better shape, while preserving history. Of course, after the modifications have been done, you will have to delete the old repo and upload the converted one.

Mercurial commit only tip

In my setup I have a central Hg repo to which I'm pushing my local changes. Say in my local clone I have a series of local commits and then I want to push the changes to the central repo. How can I push only the final state without including all of the "small" local commits that I made?
I want this because sometimes I dont want to pollute the central repo's history with all of the small local commits that I made.
Why would you want to do that? Committing small changes makes it easy to revert something. If you collect everything in one big commit, reverting a small change might not be as easy.
I agree with bjorn (and I'm upvoting his answer), what you're doing isn't a great idea -- meaningful history is a good thing. If you can't be talked out of it then what you're trying to do isn't just push the last changeset but a new changeset that is a combination of all those changesets. The easiest way to do that is to use the collapse extension, though mq or even export/import can do it. The key there is that in collapsing multiple changesets into one you're rewriting history and you're going to remove your existing changesets and replace them with that new combined changeset. Doing so violates the immutability of history that makes Mercurial so trust worthy.
How to do this without any extensions is explained in the mercurial wiki page ConcatenatingChangesets.
That page also links to a few alternative approaches with hg extensions, like the CollapseExtension.
It is possible to rewrite your history using the mq extension. Suppose the revisions you want to collapse are revs, 5,6,7 with 7 being the tip. You would accomplish this via:
# Import the revs you want to collapse into mq
# mq will create patches for each revision from 5:tip, with the name
# <local rev number>.diff
hg qimport -r5:tip
# Goto the first commit
hg qgoto 5.diff
# Fold in the other commits successively. Aside from shell magic, there is
# no command line way to specify multiple patches at once.
hg qfold 6.diff
hg qfold 7.diff
# Commit the new mq patch as a changeset of its own
hg qfinish 5.diff
Now, your repository contains only a rev 5 with the contents of what was previously revisions 5, 6, and 7.

Why does mercurial merge committed changes in the working copy?

I've been using Mercurial for a few weeks now and don't understand why when Mercurial comes to merge committed changes from two repositories it does it in the working copy?
Surely the merge could happen without the use of the working copy removing the need to shelf changes etc.
It just doesn't seem necessary to involve the working copy. Am I missing something?
There is only one working copy per repository, by definition:
The working directory is the top-level directory in a repository, in which
the plain versions of files are available to read, edit and build.
Unless your file system descends from Schrödinger's cat, you cannot have two versions of the same file at the same time, thus you cannot have two working copies.
Nevertheless, it's indeed theoretically possible to use something like a ephemeral clone (per #Ry4an) to act as the working copy of a merge, resolve conflicts there, commit, then make it disappear. You'd get a beautiful merge changeset and your intact working copy.
I can think of several ways to achieve this:
Petition hg team to do it in core
Write an extension to implement the ephemeral clone or some other way
Shelve with a temporary changeset
Shelve with MQ
I would strongly recommend #4, as I would for almost all workflow scenarios. It took me a few good days to grok MQ, but once I did I've never had to turn back.
In an MQ workflow, your working copy is always the current patch. So for the merge situation you would do:
hg qrefresh
hg qpop -a
hg update -r<merge first parent>
hg merge [-r<merge second parent>]
hg commit
hg update qparent
hg qgo <working copy patch>
You don't have to pop all patches in #2. I always do that whenever I need to deal with real changesets to avoid mixing them up with patches.
Solution #3 is really the same as #4, since a patch is a temporary changeset by definition (this is really the only thing you need for understanding MQ). It's just different commands:
hg commit -A
hg update -r<merge first parent>
hg merge [-r<merge second parent>]
hg commit
hg update -r<working copy changeset parent>
hg revert -a -r<working copy changeset>
hg strip <working copy changeset>
If you want to keep the working copy changeset and continue to commit, simply update to it in #5.
From your question it seems like you already know #4 but don't like shelving. I think shelving is good because merging is a fundamentally different task than coding (changing working copy), and shelving makes the context switch explicit and safe.
I didn't write Mercurial, so I can't say why they did it that way, but here are some of the positive results of that decision:
you can look over the results of the merge before you commit it
you can edit the results of the merge before you commit it
you're encouraged to commit frequently
If you really want to do a merge and have stuff in your working dir that you can't bear to commit don't bother with shelve just do:
cd ..
hg clone myrepo myrepo-mergeclone
hg -R myrepo-mergeclone merge
hg -R myrepo-mergeclone push myrepo
On the same file system clone is near instantaneous and uses hardlinks under the covers so it takes up almost no space past that of the temporary working copy.
As mentioned in the chapter "Merge" of HgInit:
The merge command, hg merge, took the two heads and combined them.
Then it left the result in my working directory.
It did not commit it. That gives me a chance to check that the merge is correct.
Such check can include conflicts in merge, that the user has to review:
In KDiff3, you see four panes
The top left is the original file.
Top center shows Rose her version.
Top right shows Rose my version.
The bottom pane is an editor where Rose constructs a merged file with the conflicts resolved.
So you need a working directory (a view for the merge) in order to resolve fully a merge.