<rsbecker@xxxxxxxxxxxxx> writes:
>> - Why did the repository got into this state in the first place?
>> It seems that it would be much better solution to prevent refs
>> from having garbage values in them or to prevent objects that are
>> necessary from going away than any "prune invalid refs" feature.
>
> I agree. However, there are some configurations where disk write
> caches are enabled and require a sync or some other flush
> operation to force a complete write to disk. In such situations,
> corruptions are always possible despite the best efforts by the
> application.
The question was posed to see where the current "best efforts" are
still inadequate.
>> - "fetch" still feels a wrong place to have the feature, if it is
>> about fixing a local repository corruption. You should be able
>> to recover from such a broken ref even if you are only working
>> locally without fetching from anybody.
>
> I think fsck would be a better place for this.
>
>>If you can somehow _enumerate_ such broken refs, you could drive update-ref to
>>remove them.
Interesting. "git fsck" certainly can be used to help you find out
about them. In a throw-away repository, after manually crafting
some "broken refs" (because update-ref will refuse to create a ref
pointing at a missing object):
$ git for-each-ref
9e830ad6c4f43159cef50cb1c2205f513c79bc8b commit refs/heads/master
$ echo 9e830ad6c4f43159cef50cb1c2205f513c79bc8a >.git/refs/heads/broken-missing
$ git rev-parse master: >.git/refs/heads/broken-tree
$ git rev-parse "master:foo /baz" >.git/refs/heads/broken-blob
running "git fsck" does tell you about them, ...
$ git fsck
Checking object directories: 100% (256/256), done.
error: refs/heads/broken-blob: not a commit
error: refs/heads/broken-missing: invalid sha1 pointer 9e830ad6c4f43159cef50cb1c2205f513c79bc8a
error: refs/heads/broken-tree: not a commit
... and using the information, you can
$ for r in refs/heads/broken-{blob,missing,tree}
do git update-ref -d "$r"
done
to unbreak the repository.
