Hi Bill,
> Being able to list the reflog and view previous commit messages doesn't
restore my history, or allow me to see the changes made to that history.
One of the things which (still) excites me about git is that, actually, you
can restore history using the reflog, and you can see the history leading
up to each commit.
First off, git stores history as a linked list of working copy snapshots.
To display the history for a commit, git log takes the latest commit,
follows its parent reference to get the previous commit, then finds the
next parent, etc, and prints out the commit message for each one. It can
start from any commit, including ones in the reflog. Here is what it looks
like:
git log master
git log master@{1}
The first line gets the log starting at the commit which the master branch
currently points to, that is, the most recent commit to master.
The second line uses reflog syntax to start logging from where master most
recently pointed to, that is, one step back in the reflog. master@{0}
points to the current master, master@{2} points further back etc.
Next, restoring history with the reflog. First off, a branch in git is a
reference to a commit, which gets updated whenever you commit to a branch.
Using git reset, you can change which commit a branch points to. So, if you
know the sha1 for a commit, say, from the reflog, you can change the branch
to point to that. All together, if you are on the master branch (check git
status) you can reset to a different commit like this:
git reset master@{1}
Finally, what is the gitx bug? Well, it sounds like you are left looking at
a commit with no history, which looks like it contains a snapshot of the
whole working copy. Diffs in the log diff the snapshot from one commit with
the snapshot from the previous one, so if it can't find any previous
commits there will be nothing to diff with, so the log will show everything
as new. Since commits always reference full snapshots, that means the
snapshot itself is good. The problem is finding the previous commit. GitX
has probably not set the parent commit properly, so git log can't follow
the history back.
HTH,
Douglas
On Saturday, 3 November 2012, <[email protected]> wrote:
> I've had this happen too, multiple times, doing nothing other than a
normal checkin of new changes. Checkin as usual, and suddenly *bam* every
previous checkin in log/history is gone.
> Has happened to me at least half a dozen times, with no warning or
pattern that I can find.
> This is *insane* behavior for a revision control client!
> Being able to list the reflog and view previous commit messages doesn't
restore my history, or allow me to see the changes made to that history.
> I quit using GitX because of this.
> --Bill
>
> On Thursday, October 28, 2010 8:23:17 AM UTC-6, brotherbard wrote:
>>
>> On Oct 28, 2010, at 7:43 AM, TTop wrote:
>>
>> > I was using GitX 0.7.1 to prepare a commit. Something happened -- I
>> > don't know what -- and suddenly my branch only had a single commit in
>> > it that appears to contain all the files in my tree. So I went to the
>> > command line and did this:
>> >
>> > $ git reset --soft HEAD^
>> > fatal: ambiguous argument 'HEAD^': unknown revision or path not in the
>> > working tree.
>> >
>> > When I do 'git log' in this branch, there's only one commit. Now, I
>> > had many commits in this branch a few minutes ago. I really, really,
>> > don't want to lose this.
>> >
>> > What steps should I take to attempt to recover? Is there some log to
>> > see what happened?
>>
>> Use 'git reflog' to see the history of the changes to HEAD or 'git
reflog show branchname' to see changes to just that branch. Find the last
SHA that seems valid and check it out.
>>
>> --Nathan
>>
>> http://brotherbard.com/
