[PATCH 0/3] Teach `git fsck` a new option: `--name-objects`

When using experimental features (such as worktrees), it is quite possible to end up with a repository that is a little bit corrupted. In this developer's case, the auto gc run during interactive rebases in worktrees completely messed up the reflogs.

The symptoms are broken links between commits/trees/blobs.

Trying to work around such problems can be a real challenge: while several tools will report when objects are missing, all of them simply state the SHA-1. This is not useful when the user has to kiss the offending reflog good-bye, but does not even know which one.

This patch series introduces a new option to `git fsck`: --name-objects. With this option, the fsck command will report not only the SHA-1 of missing objects, but also a name by which this object is supposed to be reachable.

Example output:

	...
	broken link from    tree b5eb6ff...  (refs/stash@{<date>}~37:)
		      to    blob ec5cf80...

Originally, I intended to teach name-rev a new mode where it would also name objects other than commits and tags, but since the objects in question were lost to a garbage collection, and therefore there would not have been any objects to call names to begin with, I had to abandon said quest.

Johannes Schindelin (3):
  fsck: refactor how to describe objects
  fsck_walk(): optionally name objects on the go
  fsck: optionally show more helpful info for broken links

 Documentation/git-fsck.txt |  9 +++++-
 builtin/fsck.c             | 77 ++++++++++++++++++++++++++++++++++++----------
 fsck.c                     | 72 +++++++++++++++++++++++++++++++++++++++++++
 fsck.h                     |  1 +
 t/t1450-fsck.sh            | 22 +++++++++++++
 5 files changed, 163 insertions(+), 18 deletions(-)

Published-As: https://github.com/dscho/git/releases/tag/fsck-name-objects-v1