Re: git mv after the fact
Show 23 quoted lines
> Le 27 mai 2026 à 19:24, Junio C Hamano <gitster@pobox.com> a écrit :
>
> Chris Torek <chris.torek@gmail.com> writes:
>
>>> Chris Torek <chris.torek@gmail.com> writes:
>>>> A flag for "git mv" would be convenient (and slightly moreefficient ...
>>>
>>
>> On Tue, May 26, 2026 at 8:09 PM Junio C Hamano <gitster@pobox.com> wrote:
>>> May be convenient, but I do not get the "efficient" part.
>>
>> A normal `git mv` renames the index entry and the file in the working
>> tree without running `git add` on the *contents*, so there's no new hash
>> computation. Presumably a `git mv --after foo bar` would do the same: verify
>> that there is no existing `bar` in the index, that there is an existing `foo` in
>> the index, and that there is no `foo` but there is a `bar` in the working tree,
>> and then it would rename (add-and-remove, really, because of sorting)
>> the index entry, without scanning the working tree contents.
>>
>> In other words, we skip reading the 3 terabyte file, or whatever.
>
> Yup, that matches what I wrote. We do not rehash and we only write
> the index just once.
One thing I wondered: if we don’t have an exact move but assume (by not hashing), doesn’t that mean the index would differ from what’s on disk? I originally thought that might be a problem, but the more I thought the more I realized that’s a fairly typical state anyway.
Just seemed like a potential footgun to me, but perhaps not worth worrying about.
Ben Knoble <ben.knoble@gmail.com>