Re: [PATCHv2] write_index: optionally allow broken null sha1s
Jonathan Nieder <jrnieder@gmail.com> writes:
Show 17 quoted lines
> In other words, why not use something like this?
>
> write_index: optionally allow broken null sha1s
>
> Commit 4337b58 (do not write null sha1s to on-disk index, 2012-07-28)
> added a safety check preventing git from writing null sha1s into the
> index. The intent was to catch errors in other parts of the code that
> might let such an entry slip into the index (or worse, a tree).
>
> Some existing repositories have some invalid trees that contain null
> sha1s already, though. Until 4337b58, a common way to clean this up
> would be to use git-filter-branch's index-filter to repair such broken
> entries. That now fails when filter-branch tries to write out the
> index.
>
> Introduce a GIT_ALLOW_NULL_SHA1 environment variable to relax this check
> and make it easier to recover from such a history.
I found this version more readable than Peff's (albeit slightly).
> After this patch, do you think (in a separate change) it would make
> sense for cache-tree.c::update_one() to check for null sha1 and error
> out unless GIT_ALLOW_NULL_SHA1 is true? That would let us get rid of
> the caveat from the last paragraph.
Hmm, interesting thought.
Junio C Hamano <gitster@pobox.com>