Re: Master and origin/master diverged

[Neal Kreitzinger <nkreitzinger@gmail.com>]

On 6/22/2012 12:53 PM, Hilco Wijbenga wrote:
> Hi all,
>
> One of my developers managed to push something that somehow "diverged"
> origin/master from everyone else's local master.
>
> A --> B --> C --> D (everybody's local master)
> |
> \--> B' --> C' --> D' --> E (origin/master)
>
> (i.e., A is the commit where things diverged; everyone's local master
> points to D but the new commit (E) that was pushed to origin/master
> uses different SHA1s for B, C, and D). I hope I explained it clearly
> enough.
>
> Now running git pull creates a merge commit joining D and E.
>
> When I asked the developer what he had done he told me everything had
> looked normal. No Git warnings, nothing strange in gitk (i.e. normal
> linear history). So I do not understand what went wrong.
>
> Does anyone have any idea as to what might have happened? Perhaps if I
> understand how this happened I might be able to prevent it from
> happening again.
>
Some ways you can prevent it from happening again:
(1) setting your canonical repo config to deny non-ff, and deny deletes:
[receive]
         denyDeletes = true
         denyNonFastforwards = true
(2) have your devs do git pull --ff-only

v/r,
neal