Re: What's cooking in git.git (Aug 2020, #07; Thu, 27)

[Jeff King <peff@peff.net>]

On Thu, Aug 27, 2020 at 02:43:02PM -0700, Junio C Hamano wrote:

> * tb/repack-clearing-midx (2020-08-26) 1 commit
>   (merged to 'next' on 2020-08-27 at a465875cbb)
>  + builtin/repack.c: invalidate MIDX only when necessary
> 
>  When a packfile is removed by "git repack", multi-pack-index gets
>  cleared; the code was taught to do so less aggressively by first
>  checking if the midx actually refers to a pack that no longer
>  exists.
> 
>  Will merge to 'master'.

This seems to break t7700 when run with midx support:

  $ git checkout e08f7bb093
  HEAD is now at e08f7bb093 builtin/repack.c: invalidate MIDX only when necessary

  $ make && (cd t && GIT_TEST_MULTI_PACK_INDEX=1 ./t7700-repack.sh -i)
  [...]
  + git repack -a -d
  Enumerating objects: 10, done.
  Counting objects: 100% (10/10), done.
  Delta compression using up to 16 threads
  Compressing objects: 100% (5/5), done.
  Writing objects: 100% (10/10), done.
  Total 10 (delta 1), reused 10 (delta 1), pack-reused 0
  fatal: error preparing packfile from multi-pack-index
  error: last command exited with $?=128
  not ok 6 - packed obs in alt ODB are repacked when local repo has packs
  #	
  #		rm -f .git/objects/pack/* &&
  #		echo new_content >>file1 &&
  #		git add file1 &&
  #		test_tick &&
  #		git commit -m more_content &&
  #		git repack &&
  #		git repack -a -d &&
  #		test_no_missing_in_packs

I didn't look into whether it's a bug in the actual code, or just a
weird interaction with the way GIT_TEST_MULTI_PACK_INDEX triggers
git-repack to write a midx. But either way we should figure that out
before it graduates.

-Peff