Re: [RFC PATCH] multi-pack-index: allow operating without pack files

On Sun, 2021-08-22 at 19:11 -0600, Martin Fick wrote:

On Sunday, August 22, 2021 8:34:43 PM MDT Derrick Stolee wrote:

quoted

On 8/20/2021 3:55 PM, Johannes Berg wrote:

quoted

Technically, multi-pack-index doesn't need pack files to exist,
but add_packed_git() today checks whether it exists or not.

Having a multi-pack-index is supposed to indicate that we have
these objects in the objects/pack directory within the specified
pack-files.

Hmm, isn't it a normal supported use case for repacking to potentially delete 
packfiles which are in the MIDX (I'm specifically thinking about when someone 
runs git gc with an older git version which knows nothing about MIDX files)?

Yeah, the multi-pack-index contains all the pack names that are there
(and then which one the object is in), and when git tries to use it,
then it doesn't really seem to have any issues?

You can "git repack -a -d" with an old version, or save the multi-pack-
index temporarily elsewhere and copy it back after repack, and things
work just fine, except of course "git multi-pack-index verify" will
complain loudly.

johannes