Re: [PATCH 1/3] ls-tree: make <tree-ish> optional

[Elijah Newren <newren@gmail.com>]

On Mon, Jul 2, 2018 at 8:58 PM, Joshua Nelson <jyn514@gmail.com> wrote:
> use syntax similar to `git-checkout` to make <tree-ish> optional for
> `ls-tree`. if <tree-ish> is omitted, default to HEAD. infer arguments as
> follows:
>
> 1. if args start with --
>         assume <tree-ish> to be HEAD
> 2. if exactly one arg precedes --, treat the argument as <tree-ish>
> 3. if more than one arg precedes --, exit with an error
> 4. if -- is not in args
>         a) if args[0] is a valid <tree-ish> object, treat is as such
>         b) else, assume <tree-ish> to be HEAD
>
> in all cases, every argument besides <tree-ish> is treated as a <path>

Cool, this is something I've wanted a few times.  Thanks for
submitting.  A few minor issues:
  1. Could you start sentences with capitals?  Thus, 'Use syntax...',
'Infer arguments...', 'In all cases...', etc.
  2. Missing Signed-off-by on this commit (and commit 2); I notice you
correctly added it to commit 3.

Also, additional issues below...

> ---
>  builtin/ls-tree.c | 39 ++++++++++++++++++++++++++++++++++-----
>  1 file changed, 34 insertions(+), 5 deletions(-)
>
> diff --git builtin/ls-tree.c builtin/ls-tree.c
> index 409da4e83..14102b052 100644
> --- builtin/ls-tree.c
> +++ builtin/ls-tree.c

Do you have diff.noprefix set?  It took me a little bit to realize
that this was the reason your patches weren't applying for me.

> @@ -153,7 +153,7 @@ int cmd_ls_tree(int argc, const char **argv, const char *prefix)
>                 chomp_prefix = strlen(prefix);
>
>         argc = parse_options(argc, argv, prefix, ls_tree_options,
> -                            ls_tree_usage, 0);
> +                            ls_tree_usage, PARSE_OPT_KEEP_DASHDASH);
>         if (full_tree) {
>                 ls_tree_prefix = prefix = NULL;
>                 chomp_prefix = 0;
> @@ -163,10 +163,39 @@ int cmd_ls_tree(int argc, const char **argv, const char *prefix)
>             ((LS_TREE_ONLY|LS_RECURSIVE) & ls_options))
>                 ls_options |= LS_SHOW_TREES;
>
> +       const char *object;
> +       short initialized = 0;

This will fail to compile under 'make DEVELOPER=1' (ISO C90 forbids
mixed declarations and code).

>         if (argc < 1)
> -               usage_with_options(ls_tree_usage, ls_tree_options);
> -       if (get_oid(argv[0], &oid))
> -               die("Not a valid object name %s", argv[0]);
> +               object = "HEAD";
> +       else {
> +               /* taken from checkout.c;
> +                * we have a simpler case because we never create a branch */

/*
 * multi-line comment style in git utilizes puts the first word on the
 * second line, and terminates on its own line, like this.
 */

Also, I was going to ask if this code should be put into a utility
function or something, but it isn't taken verbatim from checkout.c,
just adopted from there.

> +               short dash_dash_pos = -1, i = 0;
> +               for (; i < argc; i++) {

Any reason you moved the i = 0 to the line before?  I thought 'i' was
uninitialized and almost commented to that effect before I noticed
where it was.

> +                       if (!strcmp(argv[i], "--")) {
> +                               dash_dash_pos = i;
> +                               break;
> +                       }
> +               }
> +               if (dash_dash_pos == 0) {
> +                       object = "HEAD";
> +                       argv++, argc++;
> +               } else if (dash_dash_pos == 1) {
> +                       object = argv[0];
> +                       argv += 2, argc += 2;
> +               } else if (dash_dash_pos >= 2)
> +                       die(_("only one reference expected, %d given."), dash_dash_pos);
> +               else if (get_oid(argv[0], &oid)) // not a valid object
> +                       object = "HEAD";
> +               else {
> +                       argv++, argc++;
> +                       initialized = 1;
> +               }
> +       }
> +
> +       if (!initialized) // if we've already run get_oid, don't run it again
> +               if (get_oid(object, &oid))
> +                       die("Not a valid object name %s", object);
>
>         /*
>          * show_recursive() rolls its own matching code and is
> @@ -177,7 +206,7 @@ int cmd_ls_tree(int argc, const char **argv, const char *prefix)
>         parse_pathspec(&pathspec, PATHSPEC_ALL_MAGIC &
>                                   ~(PATHSPEC_FROMTOP | PATHSPEC_LITERAL),
>                        PATHSPEC_PREFER_CWD,
> -                      prefix, argv + 1);
> +                      prefix, argv);
>         for (i = 0; i < pathspec.nr; i++)
>                 pathspec.items[i].nowildcard_len = pathspec.items[i].len;
>         pathspec.has_wildcard = 0;
> --
> 2.18.GIT
>