Johannes Berg <johannes@xxxxxxxxxxxxxxxx> writes:
> The index-pack documentation explicitly states that the pack
> name is derived from the sorted list of object names, but
> that clearly isn't true. I can't seem to be able to figure
> out if this was ever changed though.
>
> Be less explicit in the docs as to what the exact output is,
> and just say that it's whatever goes into the pack name.
>
> Really it seems to be the sha1 of the entire file, without
> the checksum footer.
Please avoid "seems to be" and spend a bit of effort digging the
history especially when we are not in a hurry to get to the definite
answer. We can go "less explicit", or be a bit more informative by
saying that it is the trailer hash that is standard practice shared
across our binary files like the index and the packfile.
I think this is 1190a1ac (pack-objects: name pack files after
trailer hash, 2013-12-05). It forgot to update the comment before
write_idx_file() function when it did this change:
/*
* On entry *sha1 contains the pack content SHA1 hash, on exit it is
* the SHA1 hash of sorted object names. The objects array passed in
* will be sorted by SHA1 on exit.
*/
const char *write_idx_file(const char *index_name, struct pack_idx_entry **objects,
int nr_objects, const struct pack_idx_option *opts,
- unsigned char *sha1)
+ const unsigned char *sha1)
{
Obviously, after it turned *sha1 into 'const', it no longer is
possible for it to have anything different from what was passed in
upon exit.
> +Once the index has been created, the hash that goes into the name of
> +the pack/idx file is printed to stdout. If --stdin was also used then
> +this is prefixed by either "pack\t", or "keep\t" if a new .keep file
> +was successfully created. This is useful to remove a .keep file used
> +as a lock to prevent the race with 'git repack' mentioned above.
The change is good---I made sure that among these filve lines, what
changed was only the first one and half lines. I however would have
preferred not to see the line rewrapping.
Thanks.
