Rolling back changes in mercurial best pracitice - mercurial

Question

I am trying to undo a committed change that I have not yet pushed.
I use use TortisHG. I could not work out how to get the strip extension enabled.
There is a solution in there I suspect might be best practice, but I can't get my head around the merge part. And I don't think it solves the problem of resolving a locally committed, but un pushed change-set.
I have found rollback in Tortis does not cut the mustard.
Finally - is this easier with GIT?

Answer 1

Just update the workspace to the point before the unwanted committed change.
Then just graft subsequent bits after that change that you require working forwards in time from that location
You can then tidy up using strip

Answer 2

Almost exactly the same question was asked a couple of days ago - Discarding more than one commit in TortoiseHg. It works when the unwanted changesets are on the head of a branch. To save you the trouble of looking, I've reproduced my answer below. If you've committed desirable changesets on top of the unwanted ones, there is a slightly more complex answer using rebase, but it's not clear that that is a problem here:
In a recent mercurial (since v2.8 I think), you can make changesets obsolete which hides them from most views, yet they are still there if you find you ever want them. This is the recommended way to do what you want.
Lets say the most recent changeset is 132 and the latest good change is 130. Simply make changesets 131 & 132 obsolete like this:
hg prune -r 131::132
Couldn't be simpler (just make sure the current parent isn't one of the unwanted changesets). [And I don't see how git could make that any simpler.]
If you find you want to see the contents of the obsolete changesets, just add --hidden to the normal command line, e.g.:
hg log -r 120::132 --hidden
NB. Tortoise has a feature to view obsolete changesets, but I don't believe it yet has the ability to make them obsolete.

Answer 3

One option is to amend the old changeset. This is particularly useful is the changeset you want to undo is the tip but includes some changes you would like to revert and some that you would like to keep. Just revert the files you want undone and run hg commit --amend. This applies any working directory changes to the previous commit. The effect this will have is cancelling out the changes you wanted to get rid of.

Answer 4

The 'Keep "My" or "Their" files when doing a merge' you have mentioned from the 'best practices', is more about discarding changes from one of the branches. I believe that all you need is the "strip" extension".
You can also make a trick with MQ by importing temporarily your changesets to a patch queue and cherry-picking back only the changess that you need:
Right click on your lowest changeset that you want discard, "Modify history" -> "Import to MQ"
Open "Patch Queue" dialog and press "Unapply all patches"
Re-arrange patches in the order that you need with drag-n-drop
Apply only the patches that you need
Finalize them with right click on a changeset, "Modify history" -> "Finish patch"
Regarding enabling the "strip" extension. If you have enabled MQ extension the "strip" is activated automatically even though it's been showing as "unchecked" and "disabled". Disabling MQ (and restarting the TortoiseHG), will allow you to enable/disable "strip" explicitly.
PS: checked on Win32 machine, TortoiseHG 3.2.3
PPS: sorry for "GUIsh" way of solving the problem :-)
Update:
I tried to reproduce the command line version of described above with an older version of Mercurial.
Firstly we create a repo and fill it with changesets:
C:\temp>mkdir testhg
C:\temp>cd testhg
C:\temp\testhg>hg init
C:\temp\testhg>hg --version
Mercurial Distributed SCM (version 2.2.1)
(see http://mercurial.selenic.com for more information)
Copyright (C) 2005-2012 Matt Mackall and others
This is free software; see the source for copying conditions. There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE
C:\temp\testhg>echo test1 > file.txt
C:\temp\testhg>hg addremove
adding file.txt
C:\temp\testhg>hg ci -m "test 1"
C:\temp\testhg>echo test2 >> file.txt
C:\temp\testhg>hg ci -m "test 2"
C:\temp\testhg>echo test3 >> file.txt
C:\temp\testhg>hg ci -m "test 3"
These are our changesets:
C:\temp\testhg>hg log
2[tip] 201b257237ac 2015-01-13 17:59 +0200 Username
test 3
1 2054f00740b6 2015-01-13 17:58 +0200 Username
test 2
0 160251440fb0 2015-01-13 17:58 +0200 Username
test 1
Move two last changes into a patch queue:
C:\temp\testhg>hg qimport -r 1 -r 2
C:\temp\testhg>hg qseries
1.diff
2.diff
Remove a change in the middle (the patch file itself is still kept in patched directory though):
C:\temp\testhg>hg qremove -k 1.diff
Push back a change that we want to keep in the history and finalize it:
C:\temp\testhg>hg qpush
applying 2.diff
patching file file.txt
Hunk #1 succeeded at 2 with fuzz 2 (offset -1 lines).
now at: 2.diff
C:\temp\testhg>hg log
1[2.diff,qbase,qtip,tip] 9d0771cf5145 2015-01-13 17:59 +0200 Username
test 3
0[qparent] 160251440fb0 2015-01-13 17:58 +0200 Username
test 1
C:\temp\testhg>type file.txt
test1
test3
C:\temp\testhg>hg qfinish 1
C:\temp\testhg>hg log
1[tip] 9d0771cf5145 2015-01-13 17:59 +0200 Username
test 3
0 160251440fb0 2015-01-13 17:58 +0200 Username
test 1