[PATCH v3] repo: add paths.toplevel to repo info

From: Jayesh Daga <jayeshdaga99@gmail.com>

repo info currently does not expose the repository's working tree root, even though this information is available via `repo_get_work_tree()` and `git rev-parse --show-toplevel`.

Add a new field `paths.toplevel` to expose this value.

While doing so, document the correspondence between `git rev-parse` options and `repo info` fields to make it easier to identify missing or future additions.

For bare repositories, this value is empty, consistent with other non-applicable fields.

Signed-off-by: Jayesh Daga jayeshdaga99@gmail.com
---
    repo: add paths.toplevel to repo info
    
    repo info currently does not expose the repository's working tree root,
    even though this information is available via repo_get_work_tree().
    
    This makes it harder for scripts to retrieve the repository root through
    a structured interface, often requiring the use of git rev-parse
    --show-toplevel.
    
    Add a new field paths.toplevel to git repo info that returns the working
    tree root. For bare repositories, this value is empty, consistent with
    other non-applicable fields.
    
    This provides a consistent and script-friendly way to query repository
    paths without invoking additional commands.
    
    Signed-off-by: Jayesh Daga jayeshdaga99@gmail.com

Published-As: https://github.com/gitgitgadget/git/releases/tag/pr-git-2264%2Fjayesh0104%2Frepo-toplevel-v3
Fetch-It-Via: git fetch https://github.com/gitgitgadget/git pr-git-2264/jayesh0104/repo-toplevel-v3
Pull-Request: https://github.com/git/git/pull/2264

Range-diff vs v2:

 1:  05e34bfe2c ! 1:  8a58b6ce03 repo: add paths.toplevel to repo info
     @@ Commit message
          For bare repositories, this value is empty, consistent
          with other non-applicable fields.
      
     -    Signed-off-by: Jayesh Daga [jayeshdaga99@gmail.com](mailto:jayeshdaga99@gmail.com)
     +    Signed-off-by: Jayesh Daga jayeshdaga99@gmail.com
      
       ## builtin/repo.c ##
      @@ builtin/repo.c: static int get_layout_bare(struct repository *repo UNUSED, struct strbuf *buf)
     @@ builtin/repo.c: static int get_layout_bare(struct repository *repo UNUSED, struc
       
      +static int get_paths_toplevel(struct repository *repo, struct strbuf *buf)
      +{
     -+    const char *wt = repo_get_work_tree(repo);
     ++	const char *wt = repo_get_work_tree(repo);
      +
     -+    if (!wt)
     -+	return -1; /* match existing error style */
     ++	if (!wt)
     ++		return -1; /* match existing error style */
      +
     -+    strbuf_addstr(buf, wt);
     -+    return 0;
     ++	strbuf_addstr(buf, wt);
     ++	return 0;
      +}
      +
       static int get_layout_shallow(struct repository *repo, struct strbuf *buf)
       {
       	strbuf_addstr(buf,
     -@@ builtin/repo.c: static const struct repo_info_field repo_info_field[] = {
     +@@ builtin/repo.c: static int get_references_format(struct repository *repo, struct strbuf *buf)
     + 	return 0;
     + }
     + 
     ++/*
     ++ * rev-parse --<opt>        repo info <field>
     ++ *
     ++ * is-bare-repository      layout.bare
     ++ * is-shallow-repository   layout.shallow
     ++ * show-object-format      object.format
     ++ * show-ref-format         references.format
     ++ * show-toplevel           paths.toplevel
     ++ *
     ++ * show-cdup               <missing>
     ++ * show-prefix             <missing>
     ++ *
     ++ * Some <missing> entries may be candidates for future
     ++ * implementation, while others may not be needed.
     ++ */
     ++
     + /* repo_info_field keys must be in lexicographical order */
     + static const struct repo_info_field repo_info_field[] = {
       	{ "layout.bare", get_layout_bare },
       	{ "layout.shallow", get_layout_shallow },
       	{ "object.format", get_object_format },

 builtin/repo.c       | 28 ++++++++++++++++++++++++++++
 t/t1900-repo-info.sh | 16 ++++++++++++++++
 2 files changed, 44 insertions(+)