Re: [PATCH] Updated StGit patch detection in vcs_info

[Daniel Shahaf <d.s@daniel.shahaf.name>]

Peter Grayson wrote on Sat, Nov 12, 2022 at 10:42:21 -0500:
> The vcs_info patch detection code attempted to interrogate StGit patch
> stack state by inspecting .git/patches/applied and
> .git/patches/unapplied. As of StGit 1.0, StGit stack and patch state is
> no longer maintained via files in the .git/ directory, but is instead
> captured in the repo's object database, accessible via the
> refs/stacks/<branch> reference.
> 
> Thus zsh's approach for interrogating StGit patch state is long
> obsoleted.
> 
> This patch updates vcs_info to use StGit's prescribed interface for
> interrogating applied and unapplied patch state: the `stg series` command.
> This approach will work with effectively all versions of StGit, pre-1.0,
> 1.x, and 2.x.
> 

Great!

> The new test for StGit patches is moved to the end of the if/elif chain
> that also tests for git rebase, merge, and cherrypick states. If any of
> those operations are in progress, a StGit user will want to know about that
> instead of the StGit stack state.
> 
> N.B. it may be possible for vcs_info to interrogate StGit stack state
> in a faster manner by probing the filesystem and git object database
> directly instead of executing `stg series`, but this would require vcs_info
> to have knowledge of StGit internals across many versions.
> 

Either or both of these paragraphs might work better as a source
comment, so as to ensure future editors of this file will be aware of
these considerations.

> Signed-off-by: Peter Grayson <pete@jpgrayson.net>
> ---
>  .../VCS_Info/Backends/VCS_INFO_get_data_git    | 18 +++++++++---------
>  1 file changed, 9 insertions(+), 9 deletions(-)
> 
> diff --git a/Functions/VCS_Info/Backends/VCS_INFO_get_data_git b/Functions/VCS_Info/Backends/VCS_INFO_get_data_git
> index e45eebc8e..9edc2d140 100644
> --- a/Functions/VCS_Info/Backends/VCS_INFO_get_data_git
> +++ b/Functions/VCS_Info/Backends/VCS_INFO_get_data_git
> @@ -184,15 +184,8 @@ fi
>  VCS_INFO_adjust
>  VCS_INFO_git_getaction ${gitdir}
>  
> -local patchdir=${gitdir}/patches/${gitbranch}
> -if [[ -d $patchdir ]] && [[ -f $patchdir/applied ]] \
> -   && [[ -f $patchdir/unapplied ]]
> -then
> -    # stgit
> -    git_patches_applied=(${(f)"$(< "${patchdir}/applied")"})
> -    git_patches_unapplied=(${(f)"$(< "${patchdir}/unapplied")"})
> -    VCS_INFO_git_handle_patches
> -elif [[ -d "${gitdir}/rebase-merge" ]]; then
> +local patchdir
> +if [[ -d "${gitdir}/rebase-merge" ]]; then
>      # 'git rebase -i'
>      patchdir="${gitdir}/rebase-merge"
>      local p
> @@ -389,6 +382,13 @@ elif [[ -f "${gitdir}/CHERRY_PICK_HEAD" ]]; then
>          git_patches_unapplied=()
>      fi
>      VCS_INFO_git_handle_patches
> +elif git_patches_applied=(${(f)"$(stg series --noprefix --applied 2>/dev/null)"}); then
> +    # N.B. the "--noprefix" option is available in StGit 2.x as an alias for --no-prefix.
> +    # The former is compatible with StGit versions going back to 2008.
> +    if zstyle -t ":vcs_info:${vcs}:${usercontext}:${rrn}" get-unapplied; then
> +        git_patches_unapplied=(${(f)"$(stg series --noprefix --unapplied 2>/dev/null)"})
> +    fi
> +    VCS_INFO_git_handle_patches
>  else
>      gitmisc=''
>  fi

+1

If you wish, you can add the patches' log messages here, too (as printed
by «stg series --description»); a gen-applied-string hook can be used to
show those in the prompt.  There's an example in Misc/vcs_info-examples.
(But I'd be happy to merge the patch without this, too :))

Cheers,

Daniel