Re: [PATCH 1/2] refs: Add for_each_worktree_ref for iterating over all worktree HEADs

From: Jonathan Nieder <jrnieder@gmail.com>
Date: May 17, 2017, 00:28 UTC
Message-ID: <20170517002825.GR27400@aiede.svl.corp.google.com>
In-Reply-To: <CACpkpxn4zSdUMT-i6XWBR77sQTpr5-vudbLVTCs1_hiv7a2t_w@mail.gmail.com>

(+cc: Duy, worktree expert) Hi Manish,

Manish Goregaokar wrote:

> Git prune will happily delete commits checked out in other worktrees.
> This is probably not desired.

Yikes.  Thanks for working on it.

> (Tabs have been converted to spaces in this email sadly, because GMail
> garbles these. This should suffice for review, and I'll send the patch
> as an attachment or in some other form when done so that it can be
> cleanly applied. Let me know if this won't work.)

I don't think this will work well --- many reviewers (e.g. I am one of them) rely on being able to apply patches and inspect them locally. See the Discussion and MUA-Specific Hints sections of git-format-patch(1) for some hints about how to accomplish that.

Patch left unsnipped for reference.

Thanks, Jonathan

Show 60 quoted lines

> To ensure that `git prune` does not remove refs checked out
> in other worktrees, we need to include these HEADs in the
> set of roots. This adds the iteration function necessary
> to do this.
> 
> Signed-off-by: Manish Goregaokar <manishearth@gmail.com>
> ---
>  refs.c | 16 ++++++++++++++++
>  refs.h |  1 +
>  2 files changed, 17 insertions(+)
> 
> diff --git a/refs.c b/refs.c
> index 2d71774..27e0b60 100644
> --- a/refs.c
> +++ b/refs.c
> @@ -3,6 +3,7 @@
>   */
> 
>  #include "cache.h"
> +#include "commit.h"
>  #include "lockfile.h"
>  #include "refs.h"
>  #include "refs/refs-internal.h"
> @@ -1157,6 +1158,21 @@ int head_ref(each_ref_fn fn, void *cb_data)
>      return head_ref_submodule(NULL, fn, cb_data);
>  }
> 
> +int for_each_worktree_ref(each_ref_fn fn, void *cb_data)
> +{
> +    int i, flag, retval;
> +    struct object_id oid;
> +    struct worktree **worktrees = get_worktrees(GWT_SORT_LINKED);
> +    for (i = 0; worktrees[i]; i++) {
> +        struct commit* commit =
> lookup_commit_reference(worktrees[i]->head_sha1);
> +        oid = commit->object.oid;
> +        if (!read_ref_full("HEAD", RESOLVE_REF_READING, oid.hash, &flag)) {
> +            if (retval = fn("HEAD", &oid, flag, cb_data))
> +                return retval;
> +        }
> +    }
> +}
> +
>  /*
>   * Call fn for each reference in the specified submodule for which the
>   * refname begins with prefix. If trim is non-zero, then trim that
> diff --git a/refs.h b/refs.h
> index 9fbff90..425a853 100644
> --- a/refs.h
> +++ b/refs.h
> @@ -192,6 +192,7 @@ typedef int each_ref_fn(const char *refname,
>   * stop the iteration.
>   */
>  int head_ref(each_ref_fn fn, void *cb_data);
> +int for_each_worktree_ref(each_ref_fn fn, void *cb_data);
>  int for_each_ref(each_ref_fn fn, void *cb_data);
>  int for_each_ref_in(const char *prefix, each_ref_fn fn, void *cb_data);
>  int for_each_fullref_in(const char *prefix, each_ref_fn fn, void *cb_data,
> -- 
> 2.10.1