Re: [PATCH 2/2] Teach commit about CHERRY_PICK_HEAD

[Jonathan Nieder <jrnieder@gmail.com>]

Jay Soffian wrote:

> This change fixes that situation. A bare 'commit' will now take the
> authorship from CHERRY_PICK_HEAD and the commit message from MERGE_MSG.
> If the user wishes to reset authorship, that must now be done explicitly
> via --reset-author.

Might also be worth mentioning that it makes --amend fail in such a
situation (a change worth celebrating).

> --- a/builtin/commit.c
> +++ b/builtin/commit.c
> @@ -56,8 +56,10 @@ static const char empty_amend_advice[] =
>  
>  static unsigned char head_sha1[20];
>  
> -static char *use_message_buffer;
> +static const char *use_message_buffer;
>  static const char commit_editmsg[] = "COMMIT_EDITMSG";
> +static const char cherry_pick_head[] = "CHERRY_PICK_HEAD";
> +static const char merge_head[] = "MERGE_HEAD";

Hmm, these variables but not MERGE_MSG, MERGE_MODE, and SQUASH_MSG?

> @@ -68,6 +70,7 @@ static enum {
>  
>  static const char *logfile, *force_author;
>  static const char *template_file;
> +static const char *author_message, *author_message_buffer;

That's not a message at all, is it?  On first reading I thought it
would be a message about the author.  Maybe a comment can help.

	/* name and content of commit from which to copy authorship */

> @@ -88,7 +91,8 @@ static enum {
>  } cleanup_mode;
>  static char *cleanup_arg;
>  
> -static int use_editor = 1, initial_commit, in_merge, include_status = 1;
> +static enum commit_whence whence;
> +static int use_editor = 1, initial_commit, include_status = 1;

The name "whence" is not so self-explanatory but I don't have any
better ideas (I probably would have written "merge_or_cherry_pick"; we
can be glad you came up with something better).

> @@ -163,6 +167,36 @@ static struct option builtin_commit_options[] = {
>  	OPT_END()
>  };
>  
> +static void determine_whence(struct wt_status *s)
> +{
> +	if (file_exists(git_path(merge_head)))
> +		whence = FROM_MERGE;

Micronit: maybe COMMITTING_A_MERGE or COMMIT_DURING_MERGE to avoid
using valuable namespace?

> @@ -644,7 +678,7 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
>  	 * This final case does not modify the template message,
>  	 * it just sets the argument to the prepare-commit-msg hook.
>  	 */
> -	else if (in_merge)
> +	else if (whence == FROM_MERGE)
>  		hook_arg1 = "merge";

Perhaps:

	else if (whence == CHERRY_PICK) {
		hook_arg1 = "commit";
		hook_arg2 = author_message;
	}

> @@ -694,16 +728,18 @@ static int prepare_to_commit(const char *index_file, const char *prefix,
[...]
>  				"# If this is not correct, please remove the file\n"
>  				"#	%s\n"
>  				"# and try again.\n"
>  				"#\n",
> +				whence_s(),
> +				git_path(whence == FROM_MERGE
> +					 ? merge_head
> +					 : cherry_pick_head));

Ok.  We probably should move away from having to suggest
"rm -f .git/whatever" in the future (maybe

	git update-ref -d %s

is simpler advice?  I dunno).

> @@ -898,6 +934,27 @@ static void handle_untracked_files_arg(struct wt_status *s)
>  		die("Invalid untracked files mode '%s'", untracked_files_arg);
>  }
>  
> +static const char *read_commit_message(const char *name) {

Nice.  Opening '{' should be in the first column.

> +++ b/builtin/revert.c
[...]
> @@ -284,9 +233,7 @@ static void print_advice(void)
>  
>  	advise("after resolving the conflicts, mark the corrected paths");
>  	advise("with 'git add <paths>' or 'git rm <paths>'");
> -
> -	if (action == CHERRY_PICK)
> -		advise("and commit the result with 'git commit -c CHERRY_PICK_HEAD'");
> +	advise("and commit the result with 'git commit'");

Hoorah!

> --- a/wt-status.c
> +++ b/wt-status.c
> @@ -60,7 +60,7 @@ static void wt_status_print_unmerged_header(struct wt_status *s)
>  	color_fprintf_ln(s->fp, c, "# Unmerged paths:");
>  	if (!advice_status_hints)
>  		return;
> -	if (s->in_merge)
> +	if (s->whence != FROM_COMMIT)
>  		;
>  	else if (!s->is_initial)
>  		color_fprintf_ln(s->fp, c, "#   (use \"git reset %s <file>...\" to unstage)", s->reference);

Isn't the advice of using "git reset -- <paths>" still good in the
CHERRY_PICK case?

> @@ -77,7 +77,7 @@ static void wt_status_print_cached_header(struct wt_status *s)
>  	color_fprintf_ln(s->fp, c, "# Changes to be committed:");
>  	if (!advice_status_hints)
>  		return;
> -	if (s->in_merge)
> +	if (s->whence != FROM_COMMIT)
>  		; /* NEEDSWORK: use "git reset --unresolve"??? */

Likewise here.

> --- a/wt-status.h
> +++ b/wt-status.h
> @@ -24,6 +24,12 @@ enum untracked_status_type {
>  	SHOW_ALL_UNTRACKED_FILES
>  };
>  
> +enum commit_whence {
> +  FROM_COMMIT,
> +  FROM_MERGE,
> +  FROM_CHERRY_PICK
> +};

Style: please use tabs to indent.

> @@ -40,7 +46,7 @@ struct wt_status {
>  	const char **pathspec;
>  	int verbose;
>  	int amend;
> -	int in_merge;
> +	enum commit_whence whence;

Might benefit from a comment.

	/* whether a merge or cherry-pick is in progress */
	enum commit_whence whence;

Thanks, very readable.