* Piers Cawley <[email protected]> [2011-02-08 17:10]:
> On Mon, Feb 7, 2011 at 12:48 PM, Aristotle Pagaltzis <[email protected]> wrote:
> >* Philippe Bruhat (BooK) <[email protected]> [2011-02-07 09:50]:
> >>> You probably want this instead:
> >>>
> >>> git stash
> >>> git reset --hard HEAD^
> >>> git stash pop
> >>>
> >>> THIS is a git undo button.
> >>
> >> --mixed
> >>
> >> Resets the index but not the working tree (i.e., the
> >> changed files are preserved but not marked for commit)
> >> and reports what has not been updated. This is the
> >> default action.
> >
> >Yeah, but I *don't* want all changed files preserved. I want
> >only the changes preserved that were made *on top* of the
> >commit, but not any changes that came from the commit itself.
>
> Err... that's what it does. Stash saves a changeset, not whole
> files. You roll back to HEAD^ and then reapply the changes.
What is what what does? OK, it looks like someone or other got
royally confused. Time for a few pictures.
Initial situation:
HEAD^:foo.txt | HEAD:foo.txt | index:foo.txt | ./foo.txt
| | |
foo | foo | foo | foo
| | |
bar | bar | bar | bar
| | |
| quux | quux | baz
| | |
| | | quux
The current commit adds a line over the previous one, the index
reflects the current commit, and the working copy has some extra
changes on top of that. Now I want to get rid of the current
commit.
After `git reset --hard HEAD^`:
HEAD:foo.txt | index:foo.txt | ./foo.txt
| |
foo | foo | foo
| |
bar | bar | bar
The extra change that was in the working copy is lost.
If I do `git reset --mixed HEAD^` instead:
HEAD:foo.txt | index:foo.txt | ./foo.txt
| |
foo | foo | foo
| |
bar | bar | bar
| |
| | baz
| |
| | quux
The working copy still has the `quux` line, but it *also* has
the `baz` line that was added by the commit I wanted to throw
away. If I commit now, the spirit of the thrown-away commit will
live on.
But with `git stash ; git reset --hard HEAD^ ; git stash pop`:
HEAD:foo.txt | index:foo.txt | ./foo.txt
| |
foo | foo | foo
| |
bar | bar | bar
| |
| | baz
The stuff that was originally *only* in the working copy is still
there afterwards, yet the stuff that was in the commit I threw
away is now gone from everywhere – working copy and index too.
Hopefully that clears up why I described this as a proper undo
button and why `git reset` alone is insufficient, `--mixed` or
not.
Regards,
--
Aristotle Pagaltzis // <http://plasmasturm.org/>
