I have a file in which several separate blocks have changed in one changeset. (This is not the most recent changeset.)
Now I need to revert just one of these blocks to the status of the revision right before those changes. What is the recommended procedure for this? Does Mercurial/TortoiseHg offer any help, or should I just manually replace this block with the old contents?
If you would want a complete changeset being undone, it could be done without manual work by using hg backout. From its help:
hg backout [OPTION]... [-r] REV
reverse effect of earlier changeset
Prepare a new changeset with the effect of REV undone in the current
working directory. If no conflicts were encountered, it will be committed
immediately.
If REV is the parent of the working directory, then this new changeset is
committed automatically (unless --no-commit is specified).
Note:
'hg backout' cannot be used to fix either an unwanted or incorrect
merge.
However as you only want a single hunk reverted, you can use hg backout and then you need to use the --interactive flag for the commit so that you can pick the right hunk(s) to be committed:
hg commit --message "Revert some stuff" --interactive
Last, revert the working dir to a now unmodified state - you don't want to change back the remaining hunks
Related
Is there a way to disassociate a file on a feature branch from its parent branch, in that changes to the file on the parent branch will no longer merge into the feature branch?
ie: app/index.html [develop] changes should no longer merge into app/index.html [feature/redesign] when merging develop into feature/redesign ?
You should ask yourself why you want to do this, it sounds backwards. Anyway, the following should work: perform the merge as usual, don't care about what happens to app/index.html (that is, in case of conflict just accept something, don't think about it). Then, before doing the merge commit, revert that file to its previous revision on redesign branch. To make an example:
(on branch redesign)
hg merge develop
hg revert -r redesign app/index.html
Now hg status will still show app/index.html as modified, but if you look at its contents, they are the same as before the merge. Do the merge commit as usual:
hg commit -m 'Merge develop into redesign'
Note: you must do this each time you do a merge, there is no "dissociate" capability.
Just delete and re-create it on the branch.
Now my there's an extra few hundred lines of code in my project, scattered over half a dozen classes, and I'm not looking forward to tracking them down one by one.
No, but this is an avoidable problem
Instead of doing hg shelve, do hg commit --secret. This will create a "real" commit in the repository, which can be rebased or stripped (hg strip) when you no longer need it. It can also be folded into another changeset using hg histedit or hg fold (the latter requires the Evolve extension, which is experimental at the time of writing, while the former is interactive and may be hard to script).
The --secret flag ensures the changeset will not be accidentally pushed until you manually run hg phase -d REV on the changeset.
Yes, with a few steps. The help for unshelve specifies "If a shelved change is applied successfully, the bundle that contains the shelved changes is moved to a backup location (.hg/shelve-backup)." So hg update --clean will return you to the pre-unshelve state, unless you added changes in the mean-time, in which case you need to figure out how to recover the world prior to the unwanted patches. Then you can re-apply the patches stored in the backup individually if you wish to essentially re-do the unshelve under whatever conditions you prefer. In any event, the back-up contains the data you thought was missing.
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).
||
||
\/
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).
How can I undo my last accidentally commited (not pushed) change in Mercurial?
If possible, a way to do so with TortoiseHg would be prefered.
Update
In my concrete case I commited a changeset (not pushed). Then I pulled and updated from the server. With these new updates I decided, that my last commit is obsolete and I don't want to sync it. So it seems, that hg rollback is not exactly what I'm searching for, because it would rollback the pull instead of my commit.
One way would be hg rollback (deprecated as of Hg2.7, August 2013)
Please use hg commit --amend instead of rollback to correct mistakes in the last commit.
Roll back the last transaction in a repository.
When committing or merging, Mercurial adds the changeset entry last.
Mercurial keeps a transaction log of the name of each file touched and its length prior to the transaction. On abort, it truncates each file to its prior length. This simplicity is one benefit of making revlogs append-only. The transaction journal also allows an undo operation.
See TortoiseHg Recovery section:
This thread also details the difference between hg rollback and hg strip:
(written by Martin Geisler who also contributes on SO)
'hg rollback' will remove the last transaction. Transactions are a concept often found in databases. In Mercurial we start a transaction when certain operations are run, such as commit, push, pull...
When the operation finishes succesfully, the transaction is marked as complete. If an error occurs, the transaction is "rolled back" and the repository is left in the same state as before.
You can manually trigger a rollback with 'hg rollback'. This will undo the last transactional command. If a pull command brought 10 new changesets into the repository on different branches, then 'hg rollback' will remove them all.
Please note: there is no backup when you rollback a transaction!
'hg strip' will remove a changeset and all its descendants. The
changesets are saved as a bundle, which you can apply again if you
need them back.
ForeverWintr suggests in the comments (in 2016, 5 years later)
You can 'un-commit' files by first hg forgetting them, e.g.: hg forget filea; hg commit --amend, but that seems unintuitive.
hg strip --keep is probably a better solution for modern hg.
hg strip will completely remove a revision (and any descendants) from the repository.
To use strip you'll need to install MqExtension by adding the following lines to your .hgrc (or mercurial.ini):
[extensions]
mq =
In TortoiseHg the strip command is available in the workbench. Right click on a revision and choose 'Modify history' -> 'Strip'.
Since strip changes the the repository's history you should only use it on revisions which haven't been shared with anyone yet. If you are using mercurial 2.1+ you can uses phases to track this information. If a commit is still in the draft phase it hasn't been shared with other repositories so you can safely strip it. (Thanks to Zasurus for pointing this out).
Since you can't rollback you should merge that commit into the new head you got when you pulled. If you don't want any of the work you did in it you can easily do that using this tip.
So if you've pulled and updated to their head you can do this:
hg --config ui.merge=internal:local merge
keeps all the changes in the currently checked out revision, and none of the changes in the not-checked-out revision (the one you wrote that you no longer want).
This is a great way to do it because it keeps your history accurate and complete. If 2 years from now someone finds a bug in what you pulled down you can look in your (unused but saved) implementation of the same thing and go, "oh, I did it right". :)
hg rollback is what you want.
In TortoiseHg, the hg rollback is accomplished in the commit dialog. Open the commit dialog and select "Undo".
In the current version of TortoiseHg Workbench 4.4.1 (07.2018) you can use Repository - Rollback/undo...:
Its workaround.
If you not push to server, you will clone into new folder else washout(delete all files) from your repository folder and clone new.
I believe the more modern and simpler way to do this now is hg uncommit. Note this leaves behind an empty commit which can be useful if you want to reuse the commit message later. If you don't, use hg uncommit --no-keep to not leave the empty commit.
hg uncommit [OPTION]... [FILE]...
uncommit part or all of a local changeset
This command undoes the effect of a local commit, returning the affected
files to their uncommitted state. This means that files modified or
deleted in the changeset will be left unchanged, and so will remain
modified in the working directory.
If no files are specified, the commit will be left empty, unless --no-keep
Sorry, I am not sure what the equivalent is TortoiseHg.
after you have pulled and updated your workspace do a thg and right click on the change set you want to get rid of and then click modify history -> strip, it will remove the change set and you will point to default tip.
I ran into this issue recently, although my situation was slightly different - I had already pushed the commit I wanted to undo. I solved my problem with hg backout <revision-code>. It seems to work in a similar way to git revert. From this answer:
backout: create a new commit that is the inverse of a given commit.
Net effect is an undo, but the change remains in your history.
In TortiseHg this can be done by right clicking the commit you wish to undo and selecting Backout.... TortiseHg doc here.
I think there's an argument for creating a new undo commit instead of removing the previous commit outright. From this article about git revert:
Instead of removing the commit from the project history, it figures
out how to invert the changes introduced by the commit and appends a
new commit with the resulting inverse content. This prevents Git from
losing history, which is important for the integrity of your revision
history and for reliable collaboration.
I'm new to collaborating with Mercurial. My situation:
Another programmer changed rev 1 of a file to replace 4-space indents with 2-space indent. (I.e. changed every line.) Call that rev 2, pushed to the remote repo.
I've committed substantive changes rev 1 with various code changes in my local workspace. Call that rev 3.
I've hg pulled and hg merged without a clear idea of what was going on.
The conflicts are myriad and not really substantive.
So I really wish I'd changed my local repo to 2-space indents before merging; then the merge will be trivial (i'm supposing). But I can't seem to back up. I think I need to hg update -r 3 but it says abort: outstanding uncommitted merges.
How can I undo the merge, changes spacing in my local repo, and remerge?
BTW: if you just revert the merge you did and 3 is not your revision number you can do this:
hg update -C -r .
You can discard uncommitted changes with the -C (or --clean) flag:
hg update -C -r 3
BEWARE: Everything that was not committed will be gone!
After that you should probably use some kind of code formatter tool to do the entire operation, or at least some find and replace with regular expressions. Something as simple as replacing what matches ^____ (use 4 spaces instead of underscores) with __ (2 spaces), repeated a few times (unless you have insanely some nested code) should work.
To undo an uncommitted merge, use
hg update --clean
which will check out a clean copy of the original merge parent, losing all changes.
I apparently just needed to hg update -C -r 3, which overwrites my local files with the rev in mind (which is what I thought hg update would do; but I was wrong.) Thanks for my help!